[PATCH v20240912 1/4] Refactor float8out_internval for better performance

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[PATCH v20240912 1/4] Refactor float8out_internval for better performance
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* [PATCH v20240912 1/4] Refactor float8out_internval for better performance
@ 2024-09-11 04:19 Andy Fan <[email protected]>
  0 siblings, 0 replies; 398+ messages in thread

From: Andy Fan @ 2024-09-11 04:19 UTC (permalink / raw)

Some users like cube, geo needs calls float8out_internval to get a
string, and then copy them into its own StringInfo. In this commit,
we would let the user provide a buffer to float8out_internal so that it
can put the data to buffer directly. This commit also reuse the existing
string length to avoid another strlen call in appendStringInfoString.
---
 contrib/cube/cube.c             | 17 +++++++++++++++--
 src/backend/utils/adt/float.c   | 14 ++++++++------
 src/backend/utils/adt/geo_ops.c | 34 ++++++++++++++++++++++-----------
 src/include/catalog/pg_type.h   |  1 +
 src/include/utils/float.h       |  2 +-
 5 files changed, 48 insertions(+), 20 deletions(-)

diff --git a/contrib/cube/cube.c b/contrib/cube/cube.c
index 1fc447511a..a239acf35c 100644
--- a/contrib/cube/cube.c
+++ b/contrib/cube/cube.c
@@ -12,6 +12,7 @@
 
 #include "access/gist.h"
 #include "access/stratnum.h"
+#include "catalog/pg_type.h"
 #include "cubedata.h"
 #include "libpq/pqformat.h"
 #include "utils/array.h"
@@ -295,26 +296,38 @@ cube_out(PG_FUNCTION_ARGS)
 	StringInfoData buf;
 	int			dim = DIM(cube);
 	int			i;
+	int str_len;
 
 	initStringInfo(&buf);
 
 	appendStringInfoChar(&buf, '(');
+
+	/* 3 for ", " and 1 for '\0'. */
+	enlargeStringInfo(&buf, (MAXFLOAT8LEN + 4) * dim);
 	for (i = 0; i < dim; i++)
 	{
 		if (i > 0)
 			appendStringInfoString(&buf, ", ");
-		appendStringInfoString(&buf, float8out_internal(LL_COORD(cube, i)));
+		float8out_internal(LL_COORD(cube, i), buf.data + buf.len, &str_len);
+		buf.len += str_len;
+		buf.data[buf.len] = '\0';
 	}
 	appendStringInfoChar(&buf, ')');
 
 	if (!cube_is_point_internal(cube))
 	{
 		appendStringInfoString(&buf, ",(");
+
+		/* 3 for ", " and 1 for '\0'. */
+		enlargeStringInfo(&buf, (MAXFLOAT8LEN + 4) * dim);
 		for (i = 0; i < dim; i++)
 		{
 			if (i > 0)
 				appendStringInfoString(&buf, ", ");
-			appendStringInfoString(&buf, float8out_internal(UR_COORD(cube, i)));
+
+			float8out_internal(UR_COORD(cube, i), buf.data + buf.len, &str_len);
+			buf.len += str_len;
+			buf.data[buf.len] = '\0';
 		}
 		appendStringInfoChar(&buf, ')');
 	}
diff --git a/src/backend/utils/adt/float.c b/src/backend/utils/adt/float.c
index f709c21e1f..1f31f8540e 100644
--- a/src/backend/utils/adt/float.c
+++ b/src/backend/utils/adt/float.c
@@ -531,22 +531,24 @@ float8out(PG_FUNCTION_ARGS)
  * float8out_internal - guts of float8out()
  *
  * This is exposed for use by functions that want a reasonably
- * platform-independent way of outputting doubles.
- * The result is always palloc'd.
+ * platform-independent way of outputting doubles, output the
+ * string length to *len;
  */
 char *
-float8out_internal(double num)
+float8out_internal(double num, char *ascii, int *len)
 {
-	char	   *ascii = (char *) palloc(32);
 	int			ndig = DBL_DIG + extra_float_digits;
 
+	if (ascii == NULL)
+		ascii = (char *) palloc(MAXFLOAT8LEN);
+
 	if (extra_float_digits > 0)
 	{
-		double_to_shortest_decimal_buf(num, ascii);
+		*len = double_to_shortest_decimal_buf(num, ascii);
 		return ascii;
 	}
 
-	(void) pg_strfromd(ascii, 32, ndig, num);
+	*len = pg_strfromd(ascii, 32, ndig, num);
 	return ascii;
 }
 
diff --git a/src/backend/utils/adt/geo_ops.c b/src/backend/utils/adt/geo_ops.c
index 07d1649c7b..59f2feaa59 100644
--- a/src/backend/utils/adt/geo_ops.c
+++ b/src/backend/utils/adt/geo_ops.c
@@ -29,6 +29,7 @@
 #include <float.h>
 #include <ctype.h>
 
+#include "catalog/pg_type.h"
 #include "libpq/pqformat.h"
 #include "miscadmin.h"
 #include "nodes/miscnodes.h"
@@ -202,10 +203,12 @@ single_decode(char *num, float8 *x, char **endptr_p,
 static void
 single_encode(float8 x, StringInfo str)
 {
-	char	   *xstr = float8out_internal(x);
+	int str_len;
+	enlargeStringInfo(str, MAXFLOAT8LEN + 1);
+	float8out_internal(x, str->data + str->len, &str_len);
 
-	appendStringInfoString(str, xstr);
-	pfree(xstr);
+	str->len += str_len;
+	str->data[str->len] = '\0';
 }								/* single_encode() */
 
 static bool
@@ -254,12 +257,20 @@ fail:
 static void
 pair_encode(float8 x, float8 y, StringInfo str)
 {
-	char	   *xstr = float8out_internal(x);
-	char	   *ystr = float8out_internal(y);
+	int data_len;
+	/* the additional 2 is for ',' and '\0' */
+	enlargeStringInfo(str, MAXFLOAT8LEN * 2 + 2);
 
-	appendStringInfo(str, "%s,%s", xstr, ystr);
-	pfree(xstr);
-	pfree(ystr);
+	float8out_internal(x, str->data + str->len, &data_len);
+	str->len += data_len;
+
+	str->data[str->len] = ',';
+	str->len++;
+
+	float8out_internal(y, str->data + str->len, &data_len);
+	str->len += data_len;
+
+	str->data[str->len] = '\0';
 }
 
 static bool
@@ -1023,9 +1034,10 @@ Datum
 line_out(PG_FUNCTION_ARGS)
 {
 	LINE	   *line = PG_GETARG_LINE_P(0);
-	char	   *astr = float8out_internal(line->A);
-	char	   *bstr = float8out_internal(line->B);
-	char	   *cstr = float8out_internal(line->C);
+	int datalen;
+	char	   *astr = float8out_internal(line->A, NULL, &datalen);
+	char	   *bstr = float8out_internal(line->B, NULL, &datalen);
+	char	   *cstr = float8out_internal(line->C, NULL, &datalen);
 
 	PG_RETURN_CSTRING(psprintf("%c%s%c%s%c%s%c", LDELIM_L, astr, DELIM, bstr,
 							   DELIM, cstr, RDELIM_L));
diff --git a/src/include/catalog/pg_type.h b/src/include/catalog/pg_type.h
index e925969732..1ab8e4e4e9 100644
--- a/src/include/catalog/pg_type.h
+++ b/src/include/catalog/pg_type.h
@@ -344,6 +344,7 @@ MAKE_SYSCACHE(TYPENAMENSP, pg_type_typname_nsp_index, 64);
 
 #endif							/* EXPOSE_TO_CLIENT_CODE */
 
+#define MAXFLOAT8LEN 32
 
 extern ObjectAddress TypeShellMake(const char *typeName,
 								   Oid typeNamespace,
diff --git a/src/include/utils/float.h b/src/include/utils/float.h
index 7d1badd292..65c395299d 100644
--- a/src/include/utils/float.h
+++ b/src/include/utils/float.h
@@ -47,7 +47,7 @@ extern float8 float8in_internal(char *num, char **endptr_p,
 extern float4 float4in_internal(char *num, char **endptr_p,
 								const char *type_name, const char *orig_string,
 								struct Node *escontext);
-extern char *float8out_internal(float8 num);
+extern char *float8out_internal(float8 num, char *ascii, int *len);
 extern int	float4_cmp_internal(float4 a, float4 b);
 extern int	float8_cmp_internal(float8 a, float8 b);
 
-- 
2.45.1


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v20240912-0002-Continue-to-remove-some-unnecesary-strlen-.patch



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

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

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

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached 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] 398+ 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; 398+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

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

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

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached 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] 398+ 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; 398+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

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

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

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached 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] 398+ 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; 398+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

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

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

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached 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] 398+ 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; 398+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

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

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

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached 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] 398+ 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; 398+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

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

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

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached 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] 398+ 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; 398+ messages in thread

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

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

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached 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] 398+ 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; 398+ messages in thread

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

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

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached 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] 398+ 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; 398+ messages in thread

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

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

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached 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] 398+ 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; 398+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

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

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

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached 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] 398+ 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; 398+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

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

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

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached 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] 398+ 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; 398+ messages in thread

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

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

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached 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] 398+ 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; 398+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

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

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

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached 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] 398+ 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; 398+ messages in thread

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

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

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached 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] 398+ 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; 398+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

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

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

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached 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] 398+ 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; 398+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

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

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

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached 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] 398+ 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; 398+ messages in thread

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

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

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached 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] 398+ 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; 398+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

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

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

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached 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] 398+ 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; 398+ messages in thread

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

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

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached 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] 398+ 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; 398+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

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

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

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached 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] 398+ 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; 398+ messages in thread

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

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

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached 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] 398+ 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; 398+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

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

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

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached 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] 398+ 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; 398+ messages in thread

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

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

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached 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] 398+ 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; 398+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

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

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

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached 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] 398+ 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; 398+ messages in thread

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

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

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached 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] 398+ 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; 398+ messages in thread

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

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

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached 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] 398+ 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; 398+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

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

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

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached 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] 398+ 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; 398+ messages in thread

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

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

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached 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] 398+ 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; 398+ messages in thread

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

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

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached 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] 398+ 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; 398+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

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

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

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached 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] 398+ 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; 398+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

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

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

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached 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] 398+ 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; 398+ messages in thread

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

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

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached 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] 398+ 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; 398+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

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

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

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached 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] 398+ 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; 398+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

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

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

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached 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] 398+ 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; 398+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

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

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

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached 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] 398+ 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; 398+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

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

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

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached 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] 398+ 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; 398+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

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

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

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached 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] 398+ 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; 398+ messages in thread

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

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

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached 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] 398+ 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; 398+ messages in thread

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

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

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached 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] 398+ 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; 398+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

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

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

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached 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] 398+ 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; 398+ messages in thread

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

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

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached 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] 398+ 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; 398+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

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

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

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached 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] 398+ 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; 398+ messages in thread

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

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

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached 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] 398+ 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; 398+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

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

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

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached 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] 398+ 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; 398+ messages in thread

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

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

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached 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] 398+ 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; 398+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

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

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

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached 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] 398+ 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; 398+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

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

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

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached 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] 398+ 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; 398+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

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

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

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached 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] 398+ 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; 398+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

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

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

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached 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] 398+ 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; 398+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

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

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

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached 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] 398+ 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; 398+ messages in thread

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

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

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached 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] 398+ 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; 398+ messages in thread

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

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

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached 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] 398+ 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; 398+ messages in thread

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

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

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached 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] 398+ 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; 398+ messages in thread

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

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

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached 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] 398+ 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; 398+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

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

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

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached 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] 398+ 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; 398+ messages in thread

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

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

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached 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] 398+ 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; 398+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

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

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

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


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



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached 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] 398+ 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; 398+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached 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] 398+ 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; 398+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached 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] 398+ 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; 398+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached 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] 398+ 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; 398+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached 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] 398+ 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; 398+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached 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] 398+ 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; 398+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached 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] 398+ 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; 398+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached 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] 398+ 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; 398+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached 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] 398+ 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; 398+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached 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] 398+ 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; 398+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached 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] 398+ 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; 398+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached 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] 398+ 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; 398+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached 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] 398+ 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; 398+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached 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] 398+ 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; 398+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached 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] 398+ 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; 398+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached 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] 398+ 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; 398+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached 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] 398+ 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; 398+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached 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] 398+ 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; 398+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached 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] 398+ 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; 398+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached 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] 398+ 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; 398+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached 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] 398+ 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; 398+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached 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] 398+ 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; 398+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached 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] 398+ 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; 398+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached 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] 398+ 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; 398+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached 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] 398+ 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; 398+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached 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] 398+ 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; 398+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached 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] 398+ 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; 398+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached 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] 398+ 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; 398+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached 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] 398+ 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; 398+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached 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] 398+ 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; 398+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached 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] 398+ 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; 398+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached 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] 398+ 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; 398+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached 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] 398+ 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; 398+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached 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] 398+ 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; 398+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached 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] 398+ 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; 398+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached 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] 398+ 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; 398+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached 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] 398+ 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; 398+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached 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] 398+ 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; 398+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached 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] 398+ 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; 398+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached backends */
+	pg_atomic_uint32 refcnt;	/* number of attached backends */
 } SharedFileSet;
 
 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0007-convert-ParallelBlockTableScanDescData-phs_-start.patch



^ permalink  raw  reply  [nested|flat] 398+ 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; 398+ messages in thread

From: Nathan Bossart @ 2026-07-09 19:53 UTC (permalink / raw)

---
 src/backend/storage/file/sharedfileset.c | 27 +++++++++---------------
 src/include/storage/sharedfileset.h      |  5 ++---
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/backend/storage/file/sharedfileset.c b/src/backend/storage/file/sharedfileset.c
index d76bd72dc63..4f12f92beae 100644
--- a/src/backend/storage/file/sharedfileset.c
+++ b/src/backend/storage/file/sharedfileset.c
@@ -38,8 +38,7 @@ void
 SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 {
 	/* Initialize the shared fileset specific members. */
-	SpinLockInit(&fileset->mutex);
-	fileset->refcnt = 1;
+	pg_atomic_init_u32(&fileset->refcnt, 1);
 
 	/* Initialize the fileset. */
 	FileSetInit(&fileset->fs);
@@ -55,19 +54,15 @@ SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
 void
 SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg)
 {
-	bool		success;
+	uint32		refcnt;
 
-	SpinLockAcquire(&fileset->mutex);
-	if (fileset->refcnt == 0)
-		success = false;
-	else
-	{
-		++fileset->refcnt;
-		success = true;
-	}
-	SpinLockRelease(&fileset->mutex);
+	refcnt = pg_atomic_read_u32(&fileset->refcnt);
+	while (refcnt != 0 &&
+		   !pg_atomic_compare_exchange_u32(&fileset->refcnt, &refcnt,
+										   refcnt + 1))
+		;
 
-	if (!success)
+	if (refcnt == 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("could not attach to a SharedFileSet that is already destroyed")));
@@ -98,11 +93,9 @@ SharedFileSetOnDetach(dsm_segment *segment, Datum datum)
 	bool		unlink_all = false;
 	SharedFileSet *fileset = (SharedFileSet *) DatumGetPointer(datum);
 
-	SpinLockAcquire(&fileset->mutex);
-	Assert(fileset->refcnt > 0);
-	if (--fileset->refcnt == 0)
+	Assert(pg_atomic_read_u32(&fileset->refcnt) > 0);
+	if (pg_atomic_sub_fetch_u32(&fileset->refcnt, 1) == 0)
 		unlink_all = true;
-	SpinLockRelease(&fileset->mutex);
 
 	/*
 	 * If we are the last to detach, we delete the directory in all
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
index 904396e7173..d89626ae64b 100644
--- a/src/include/storage/sharedfileset.h
+++ b/src/include/storage/sharedfileset.h
@@ -15,10 +15,10 @@
 #ifndef SHAREDFILESET_H
 #define SHAREDFILESET_H
 
+#include "port/atomics.h"
 #include "storage/dsm.h"
 #include "storage/fd.h"
 #include "storage/fileset.h"
-#include "storage/spin.h"
 
 /*
  * A set of temporary files that can be shared by multiple backends.
@@ -26,8 +26,7 @@
 typedef struct SharedFileSet
 {
 	FileSet		fs;
-	slock_t		mutex;			/* mutex protecting the reference count */
-	int			refcnt;			/* number of attached 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] 398+ messages in thread

end of thread, other threads:[~2026-07-09 19:53 UTC | newest]

Thread overview: 398+ messages (download: mbox mbox.gz follow: Atom feed)
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2024-09-11 04:19 [PATCH v20240912 1/4] Refactor float8out_internval for better performance Andy Fan <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v1 6/8] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>
2026-07-09 19:53 [PATCH v2 7/9] convert SharedFileSet->refcnt to an atomic Nathan Bossart <[email protected]>

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