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[PATCH v1 3/7] Row pattern recognition patch (planner).
426+ messages / 2 participants
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* [PATCH v1 3/7] Row pattern recognition patch (planner).
@ 2023-06-25 11:48 Tatsuo Ishii <[email protected]>
  0 siblings, 0 replies; 426+ messages in thread

From: Tatsuo Ishii @ 2023-06-25 11:48 UTC (permalink / raw)

---
 src/backend/optimizer/plan/createplan.c | 13 ++++++++++---
 src/include/nodes/plannodes.h           |  9 +++++++++
 2 files changed, 19 insertions(+), 3 deletions(-)

diff --git a/src/backend/optimizer/plan/createplan.c b/src/backend/optimizer/plan/createplan.c
index 4bb38160b3..5ac65248a2 100644
--- a/src/backend/optimizer/plan/createplan.c
+++ b/src/backend/optimizer/plan/createplan.c
@@ -287,8 +287,8 @@ static WindowAgg *make_windowagg(List *tlist, Index winref,
 								 int frameOptions, Node *startOffset, Node *endOffset,
 								 Oid startInRangeFunc, Oid endInRangeFunc,
 								 Oid inRangeColl, bool inRangeAsc, bool inRangeNullsFirst,
-								 List *runCondition, List *qual, bool topWindow,
-								 Plan *lefttree);
+								 List *runCondition, List *patternVariable, List *patternRegexp, List *defineClause,
+								 List *qual, bool topWindow, Plan *lefttree);
 static Group *make_group(List *tlist, List *qual, int numGroupCols,
 						 AttrNumber *grpColIdx, Oid *grpOperators, Oid *grpCollations,
 						 Plan *lefttree);
@@ -2684,6 +2684,9 @@ create_windowagg_plan(PlannerInfo *root, WindowAggPath *best_path)
 						  wc->inRangeAsc,
 						  wc->inRangeNullsFirst,
 						  wc->runCondition,
+						  wc->patternVariable,
+						  wc->patternRegexp,
+						  wc->defineClause,
 						  best_path->qual,
 						  best_path->topwindow,
 						  subplan);
@@ -6581,7 +6584,8 @@ make_windowagg(List *tlist, Index winref,
 			   int frameOptions, Node *startOffset, Node *endOffset,
 			   Oid startInRangeFunc, Oid endInRangeFunc,
 			   Oid inRangeColl, bool inRangeAsc, bool inRangeNullsFirst,
-			   List *runCondition, List *qual, bool topWindow, Plan *lefttree)
+			   List *runCondition, List *patternVariable, List *patternRegexp, List *defineClause,
+			   List *qual, bool topWindow, Plan *lefttree)
 {
 	WindowAgg  *node = makeNode(WindowAgg);
 	Plan	   *plan = &node->plan;
@@ -6607,6 +6611,9 @@ make_windowagg(List *tlist, Index winref,
 	node->inRangeAsc = inRangeAsc;
 	node->inRangeNullsFirst = inRangeNullsFirst;
 	node->topWindow = topWindow;
+	node->patternVariable = patternVariable;
+	node->patternRegexp = patternRegexp;
+	node->defineClause = defineClause;
 
 	plan->targetlist = tlist;
 	plan->lefttree = lefttree;
diff --git a/src/include/nodes/plannodes.h b/src/include/nodes/plannodes.h
index 1b787fe031..eb511176ac 100644
--- a/src/include/nodes/plannodes.h
+++ b/src/include/nodes/plannodes.h
@@ -1096,6 +1096,15 @@ typedef struct WindowAgg
 	/* nulls sort first for in_range tests? */
 	bool		inRangeNullsFirst;
 
+	/* Row Pattern Recognition PATTERN variable name (list of String) */
+	List		*patternVariable;
+
+	/* Row Pattern Recognition PATTERN regular expression quantifier ('+' or ''. list of String) */
+	List		*patternRegexp;
+
+	/* Row Pattern Recognition DEFINE clause (list of TargetEntry) */
+	List	   *defineClause;
+
 	/*
 	 * false for all apart from the WindowAgg that's closest to the root of
 	 * the plan
-- 
2.25.1


----Next_Part(Sun_Jun_25_21_05_09_2023_126)--
Content-Type: Text/X-Patch; charset=us-ascii
Content-Transfer-Encoding: 7bit
Content-Disposition: inline;
 filename="v1-0004-Row-pattern-recognition-patch-executor.patch"



^ permalink  raw  reply  [nested|flat] 426+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 426+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 426+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 426+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 426+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 426+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 426+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 426+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 426+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 426+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 426+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 426+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 426+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 426+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 426+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 426+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 426+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 426+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 426+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 426+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 426+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 426+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 426+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 426+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 426+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 426+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 426+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 426+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 426+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 426+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 426+ messages in thread

* [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 426+ messages in thread

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

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

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached 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] 426+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 426+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 426+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 426+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 426+ messages in thread

* [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 426+ messages in thread

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

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

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached 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] 426+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 426+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 426+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 426+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 426+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 426+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 426+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 426+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 426+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 426+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 426+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 426+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 426+ messages in thread

* [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 426+ messages in thread

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

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

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached 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] 426+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 426+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 426+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 426+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 426+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 426+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 426+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 426+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 426+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 426+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 426+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 426+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 426+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 426+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 426+ messages in thread

* [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 426+ messages in thread

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

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

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached 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] 426+ messages in thread

* [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 426+ messages in thread

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

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

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached 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] 426+ messages in thread

* [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 426+ messages in thread

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

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

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached 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] 426+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 426+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 426+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 426+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 426+ messages in thread

* [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 426+ messages in thread

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

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

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached 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] 426+ messages in thread

* [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 426+ messages in thread

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

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

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached 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] 426+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 426+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 426+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 426+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 426+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 426+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 426+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 426+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 426+ messages in thread

* [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 426+ messages in thread

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

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

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached 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] 426+ messages in thread

* [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 426+ messages in thread

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

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

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached 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] 426+ messages in thread

* [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 426+ messages in thread

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

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

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached 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] 426+ messages in thread

* [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 426+ messages in thread

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

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

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached 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] 426+ messages in thread

* [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 426+ messages in thread

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

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

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached 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] 426+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 426+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 426+ messages in thread

* [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 426+ messages in thread

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

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

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached 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] 426+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 426+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 426+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 426+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 426+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 426+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 426+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 426+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 426+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 426+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 426+ messages in thread

* [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 426+ messages in thread

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

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

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached 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] 426+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 426+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 426+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 426+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 426+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 426+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 426+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 426+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 426+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 426+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 426+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 426+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 426+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 426+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 426+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 426+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 426+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 426+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 426+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 426+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 426+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 426+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 426+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 426+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 426+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 426+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 426+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 426+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 426+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 426+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 426+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 426+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 426+ messages in thread

* [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 426+ messages in thread

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

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

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached 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] 426+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 426+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 426+ messages in thread

* [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 426+ messages in thread

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

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

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached 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] 426+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 426+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 426+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 426+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 426+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 426+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 426+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 426+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 426+ messages in thread

* [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 426+ messages in thread

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

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

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached 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] 426+ messages in thread

* [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 426+ messages in thread

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

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

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached 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] 426+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 426+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 426+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 426+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 426+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 426+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 426+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 426+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 426+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 426+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 426+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 426+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 426+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 426+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 426+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 426+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 426+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 426+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 426+ messages in thread

* [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 426+ messages in thread

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

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

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached 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] 426+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 426+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 426+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 426+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 426+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 426+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 426+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 426+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 426+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 426+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 426+ messages in thread

* [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 426+ messages in thread

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

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

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached 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] 426+ messages in thread

* [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 426+ messages in thread

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

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

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached 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] 426+ messages in thread

* [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 426+ messages in thread

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

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

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached 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] 426+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 426+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 426+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 426+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 426+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 426+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 426+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 426+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 426+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 426+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 426+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 426+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 426+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 426+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 426+ messages in thread

* [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 426+ messages in thread

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

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

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached 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] 426+ messages in thread

* [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 426+ messages in thread

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

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

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached 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] 426+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 426+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 426+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 426+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 426+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 426+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 426+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 426+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 426+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 426+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 426+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 426+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 426+ messages in thread

* [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 426+ messages in thread

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

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

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached 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] 426+ messages in thread

* [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 426+ messages in thread

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

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

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached 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] 426+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 426+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 426+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 426+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 426+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 426+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 426+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 426+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 426+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 426+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 426+ messages in thread

* [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 426+ messages in thread

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

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

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached 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] 426+ messages in thread

* [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 426+ messages in thread

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

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

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached 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] 426+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 426+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 426+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 426+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 426+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 426+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 426+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 426+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 426+ messages in thread

* [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 426+ messages in thread

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

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

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached 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] 426+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 426+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 426+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 426+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 426+ messages in thread

* [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 426+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 426+ messages in thread

* [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic
@ 2026-07-09 19:53 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 426+ messages in thread

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

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

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached 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] 426+ messages in thread