[PATCH v2] Repurpose PROC_COPYABLE_FLAGS as PROC_XMIN

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[PATCH v2] Repurpose PROC_COPYABLE_FLAGS as PROC_XMIN_FLAGS
440+ messages / 2 participants
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* [PATCH v2] Repurpose PROC_COPYABLE_FLAGS as PROC_XMIN_FLAGS
@ 2022-05-14 14:51 Alvaro Herrera <alvherre@alvh.no-ip.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Alvaro Herrera @ 2022-05-14 14:51 UTC (permalink / raw)

This is a slight, convenient semantics change from what commit
0f0cfb494004 introduced that lets us simplify the coding in the one
place where it is used.
---
 src/backend/storage/ipc/procarray.c | 17 +++++++----------
 src/include/storage/proc.h          |  7 +++----
 2 files changed, 10 insertions(+), 14 deletions(-)

diff --git a/src/backend/storage/ipc/procarray.c b/src/backend/storage/ipc/procarray.c
index ca22336e35..cd58c5faf0 100644
--- a/src/backend/storage/ipc/procarray.c
+++ b/src/backend/storage/ipc/procarray.c
@@ -2685,17 +2685,14 @@ ProcArrayInstallRestoredXmin(TransactionId xmin, PGPROC *proc)
 		TransactionIdIsNormal(xid) &&
 		TransactionIdPrecedesOrEquals(xid, xmin))
 	{
-		/* Install xmin */
+		/*
+		 * Install xmin and propagate the statusFlags that affect how the
+		 * value is interpreted by vacuum.
+		 */
 		MyProc->xmin = TransactionXmin = xmin;
-
-		/* walsender cheats by passing proc == MyProc, don't check its flags */
-		if (proc != MyProc)
-		{
-			/* Flags being copied must be valid copy-able flags. */
-			Assert((proc->statusFlags & (~PROC_COPYABLE_FLAGS)) == 0);
-			MyProc->statusFlags = proc->statusFlags;
-			ProcGlobal->statusFlags[MyProc->pgxactoff] = MyProc->statusFlags;
-		}
+		MyProc->statusFlags = (MyProc->statusFlags & ~PROC_XMIN_FLAGS) |
+			(proc->statusFlags & PROC_XMIN_FLAGS);
+		ProcGlobal->statusFlags[MyProc->pgxactoff] = MyProc->statusFlags;
 
 		result = true;
 	}
diff --git a/src/include/storage/proc.h b/src/include/storage/proc.h
index 15be21c00a..2579e619eb 100644
--- a/src/include/storage/proc.h
+++ b/src/include/storage/proc.h
@@ -69,11 +69,10 @@ struct XidCache
 	(PROC_IN_VACUUM | PROC_IN_SAFE_IC | PROC_VACUUM_FOR_WRAPAROUND)
 
 /*
- * Flags that are valid to copy from another proc, the parallel leader
- * process in practice.  Currently, flags that are set during parallel
- * vacuum and parallel index creation are allowed.
+ * Xmin-related flags. Make sure any flags that affect how the process' Xmin
+ * value is interpreted by VACUUM are included here.
  */
-#define		PROC_COPYABLE_FLAGS (PROC_IN_VACUUM | PROC_IN_SAFE_IC)
+#define		PROC_XMIN_FLAGS (PROC_IN_VACUUM | PROC_IN_SAFE_IC)
 
 /*
  * We allow a small number of "weak" relation locks (AccessShareLock,
-- 
2.30.2


--zgl76stv2tlmzxb2--





^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Xf36GNcW+0xZNily
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v2-0008-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Xf36GNcW+0xZNily
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v2-0008-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Xf36GNcW+0xZNily
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v2-0008-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Xf36GNcW+0xZNily
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v2-0008-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Xf36GNcW+0xZNily
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v2-0008-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Xf36GNcW+0xZNily
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v2-0008-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Xf36GNcW+0xZNily
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v2-0008-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Xf36GNcW+0xZNily
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v2-0008-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Xf36GNcW+0xZNily
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v2-0008-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Xf36GNcW+0xZNily
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v2-0008-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Xf36GNcW+0xZNily
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v2-0008-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Xf36GNcW+0xZNily
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v2-0008-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Xf36GNcW+0xZNily
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v2-0008-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Xf36GNcW+0xZNily
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v2-0008-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Xf36GNcW+0xZNily
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v2-0008-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Xf36GNcW+0xZNily
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v2-0008-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Xf36GNcW+0xZNily
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v2-0008-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Xf36GNcW+0xZNily
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v2-0008-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Xf36GNcW+0xZNily
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v2-0008-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Xf36GNcW+0xZNily
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v2-0008-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Xf36GNcW+0xZNily
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v2-0008-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Xf36GNcW+0xZNily
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v2-0008-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Xf36GNcW+0xZNily
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v2-0008-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Xf36GNcW+0xZNily
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v2-0008-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Xf36GNcW+0xZNily
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v2-0008-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Xf36GNcW+0xZNily
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v2-0008-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Xf36GNcW+0xZNily
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v2-0008-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Xf36GNcW+0xZNily
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v2-0008-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Xf36GNcW+0xZNily
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v2-0008-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Xf36GNcW+0xZNily
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v2-0008-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Xf36GNcW+0xZNily
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v2-0008-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Xf36GNcW+0xZNily
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v2-0008-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Xf36GNcW+0xZNily
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v2-0008-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Xf36GNcW+0xZNily
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v2-0008-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Xf36GNcW+0xZNily
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v2-0008-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Xf36GNcW+0xZNily
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v2-0008-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Xf36GNcW+0xZNily
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v2-0008-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Xf36GNcW+0xZNily
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v2-0008-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Xf36GNcW+0xZNily
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v2-0008-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Xf36GNcW+0xZNily
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v2-0008-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Xf36GNcW+0xZNily
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v2-0008-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Xf36GNcW+0xZNily
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v2-0008-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Xf36GNcW+0xZNily
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v2-0008-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Xf36GNcW+0xZNily
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v2-0008-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Xf36GNcW+0xZNily
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v2-0008-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Xf36GNcW+0xZNily
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v2-0008-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Xf36GNcW+0xZNily
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v2-0008-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Xf36GNcW+0xZNily
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v2-0008-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Xf36GNcW+0xZNily
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v2-0008-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Xf36GNcW+0xZNily
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v2-0008-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Xf36GNcW+0xZNily
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v2-0008-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Xf36GNcW+0xZNily
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v2-0008-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Xf36GNcW+0xZNily
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v2-0008-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Xf36GNcW+0xZNily
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v2-0008-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Xf36GNcW+0xZNily
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v2-0008-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Xf36GNcW+0xZNily
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v2-0008-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Xf36GNcW+0xZNily
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v2-0008-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Xf36GNcW+0xZNily
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v2-0008-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Xf36GNcW+0xZNily
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v2-0008-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Xf36GNcW+0xZNily
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v2-0008-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Xf36GNcW+0xZNily
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v2-0008-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Xf36GNcW+0xZNily
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v2-0008-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Xf36GNcW+0xZNily
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v2-0008-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Xf36GNcW+0xZNily
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v2-0008-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Xf36GNcW+0xZNily
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v2-0008-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Xf36GNcW+0xZNily
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v2-0008-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Xf36GNcW+0xZNily
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v2-0008-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Xf36GNcW+0xZNily
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v2-0008-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Xf36GNcW+0xZNily
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v2-0008-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Xf36GNcW+0xZNily
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v2-0008-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Xf36GNcW+0xZNily
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v2-0008-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Xf36GNcW+0xZNily
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v2-0008-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Xf36GNcW+0xZNily
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v2-0008-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Xf36GNcW+0xZNily
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v2-0008-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Xf36GNcW+0xZNily
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v2-0008-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Xf36GNcW+0xZNily
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v2-0008-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Xf36GNcW+0xZNily
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v2-0008-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Xf36GNcW+0xZNily
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v2-0008-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Xf36GNcW+0xZNily
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v2-0008-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Xf36GNcW+0xZNily
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v2-0008-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Xf36GNcW+0xZNily
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v2-0008-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Xf36GNcW+0xZNily
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v2-0008-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Xf36GNcW+0xZNily
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v2-0008-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Xf36GNcW+0xZNily
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v2-0008-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Xf36GNcW+0xZNily
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v2-0008-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Xf36GNcW+0xZNily
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v2-0008-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Xf36GNcW+0xZNily
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v2-0008-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Xf36GNcW+0xZNily
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v2-0008-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Xf36GNcW+0xZNily
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v2-0008-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Xf36GNcW+0xZNily
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v2-0008-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Xf36GNcW+0xZNily
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v2-0008-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Xf36GNcW+0xZNily
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v2-0008-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Xf36GNcW+0xZNily
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v2-0008-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Xf36GNcW+0xZNily
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v2-0008-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Xf36GNcW+0xZNily
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v2-0008-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Xf36GNcW+0xZNily
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v2-0008-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Xf36GNcW+0xZNily
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v2-0008-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Xf36GNcW+0xZNily
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v2-0008-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Xf36GNcW+0xZNily
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v2-0008-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Xf36GNcW+0xZNily
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v2-0008-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Xf36GNcW+0xZNily
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v2-0008-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Xf36GNcW+0xZNily
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v2-0008-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Xf36GNcW+0xZNily
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v2-0008-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Xf36GNcW+0xZNily
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v2-0008-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Xf36GNcW+0xZNily
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v2-0008-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Xf36GNcW+0xZNily
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v2-0008-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Xf36GNcW+0xZNily
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v2-0008-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Xf36GNcW+0xZNily
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v2-0008-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Xf36GNcW+0xZNily
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v2-0008-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Xf36GNcW+0xZNily
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v2-0008-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Xf36GNcW+0xZNily
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v2-0008-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Xf36GNcW+0xZNily
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v2-0008-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Xf36GNcW+0xZNily
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v2-0008-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Xf36GNcW+0xZNily
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v2-0008-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Xf36GNcW+0xZNily
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v2-0008-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Xf36GNcW+0xZNily
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v2-0008-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Xf36GNcW+0xZNily
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v2-0008-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 440+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 440+ messages in thread

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Thread overview: 440+ messages (download: mbox mbox.gz follow: Atom feed)
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2022-05-14 14:51 [PATCH v2] Repurpose PROC_COPYABLE_FLAGS as PROC_XMIN_FLAGS Alvaro Herrera <alvherre@alvh.no-ip.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
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2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
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2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
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2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
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2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
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2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <nathan@postgresql.org>

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