Invent ResourceOwner mechanism as per my recent proposal, and use it to

keep track of portal-related resources separately from transaction-related
resources.  This allows cursors to work in a somewhat sane fashion with
nested transactions.  For now, cursor behavior is non-subtransactional,
that is a cursor's state does not roll back if you abort a subtransaction
that fetched from the cursor.  We might want to change that later.

Author: tglsfdc

contrib/userlock/user_locks.c

@@ -75,7 +75,7 @@ user_write_unlock_oid(Oid oid)
 int
 user_unlock_all(void)
 {
-	return LockReleaseAll(USER_LOCKMETHOD, MyProc, ReleaseAll, 0, NULL);
+	return LockReleaseAll(USER_LOCKMETHOD, MyProc, true);
 }
 
 /* end of file */

src/backend/access/gist/gistscan.c

@@ -8,7 +8,7 @@
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/access/gist/gistscan.c,v 1.52 2004/07/01 00:49:27 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/access/gist/gistscan.c,v 1.53 2004/07/17 03:27:20 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -17,6 +17,7 @@
 #include "access/genam.h"
 #include "access/gist.h"
 #include "access/gistscan.h"
+#include "utils/resowner.h"
 
 
 /* routines defined and used here */
@@ -41,7 +42,7 @@ static void adjustiptr(IndexScanDesc s, ItemPointer iptr,
 typedef struct GISTScanListData
 {
 	IndexScanDesc gsl_scan;
-	TransactionId gsl_creatingXid;
+	ResourceOwner gsl_owner;
 	struct GISTScanListData *gsl_next;
 } GISTScanListData;
 
@@ -224,7 +225,7 @@ gistregscan(IndexScanDesc s)
 
 	l = (GISTScanList) palloc(sizeof(GISTScanListData));
 	l->gsl_scan = s;
-	l->gsl_creatingXid = GetCurrentTransactionId();
+	l->gsl_owner = CurrentResourceOwner;
 	l->gsl_next = GISTScans;
 	GISTScans = l;
 }
@@ -253,52 +254,28 @@ gistdropscan(IndexScanDesc s)
 }
 
 /*
- * AtEOXact_gist() --- clean up gist subsystem at xact abort or commit.
+ * ReleaseResources_gist() --- clean up gist subsystem resources.
  *
  * This is here because it needs to touch this module's static var GISTScans.
  */
 void
-AtEOXact_gist(void)
-{
-	/*
-	 * Note: these actions should only be necessary during xact abort; but
-	 * they can't hurt during a commit.
-	 */
-
-	/*
-	 * Reset the active-scans list to empty. We do not need to free the
-	 * list elements, because they're all palloc()'d, so they'll go away
-	 * at end of transaction anyway.
-	 */
-	GISTScans = NULL;
-}
-
-/*
- * AtEOSubXact_gist() --- clean up gist subsystem at subxact abort or commit.
- *
- * This is here because it needs to touch this module's static var GISTScans.
- */
-void
-AtEOSubXact_gist(TransactionId childXid)
+ReleaseResources_gist(void)
 {
 	GISTScanList l;
 	GISTScanList prev;
 	GISTScanList next;
 
 	/*
-	 * Note: these actions should only be necessary during xact abort; but
-	 * they can't hurt during a commit.
-	 */
-
-	/*
-	 * Forget active scans that were started in this subtransaction.
+	 * Note: this should be a no-op during normal query shutdown.
+	 * However, in an abort situation ExecutorEnd is not called and so
+	 * there may be open index scans to clean up.
 	 */
 	prev = NULL;
 
 	for (l = GISTScans; l != NULL; l = next)
 	{
 		next = l->gsl_next;
-		if (l->gsl_creatingXid == childXid)
+		if (l->gsl_owner == CurrentResourceOwner)
 		{
 			if (prev == NULL)
 				GISTScans = next;

src/backend/access/hash/hashscan.c

@@ -8,20 +8,21 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/access/hash/hashscan.c,v 1.34 2004/07/01 00:49:29 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/access/hash/hashscan.c,v 1.35 2004/07/17 03:27:40 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
 
 #include "postgres.h"
 
 #include "access/hash.h"
+#include "utils/resowner.h"
 
 
 typedef struct HashScanListData
 {
 	IndexScanDesc hashsl_scan;
-	TransactionId hashsl_creatingXid;
+	ResourceOwner hashsl_owner;
 	struct HashScanListData *hashsl_next;
 } HashScanListData;
 
@@ -31,52 +32,28 @@ static HashScanList HashScans = NULL;
 
 
 /*
- * AtEOXact_hash() --- clean up hash subsystem at xact abort or commit.
+ * ReleaseResources_hash() --- clean up hash subsystem resources.
  *
  * This is here because it needs to touch this module's static var HashScans.
  */
 void
-AtEOXact_hash(void)
-{
-	/*
-	 * Note: these actions should only be necessary during xact abort; but
-	 * they can't hurt during a commit.
-	 */
-
-	/*
-	 * Reset the active-scans list to empty. We do not need to free the
-	 * list elements, because they're all palloc()'d, so they'll go away
-	 * at end of transaction anyway.
-	 */
-	HashScans = NULL;
-}
-
-/*
- * AtEOSubXact_hash() --- clean up hash subsystem at subxact abort or commit.
- *
- * This is here because it needs to touch this module's static var HashScans.
- */
-void
-AtEOSubXact_hash(TransactionId childXid)
+ReleaseResources_hash(void)
 {
 	HashScanList l;
 	HashScanList prev;
 	HashScanList next;
 
 	/*
-	 * Note: these actions should only be necessary during xact abort; but
-	 * they can't hurt during a commit.
-	 */
-
-	/*
-	 * Forget active scans that were started in this subtransaction.
+	 * Note: this should be a no-op during normal query shutdown.
+	 * However, in an abort situation ExecutorEnd is not called and so
+	 * there may be open index scans to clean up.
 	 */
 	prev = NULL;
 
 	for (l = HashScans; l != NULL; l = next)
 	{
 		next = l->hashsl_next;
-		if (l->hashsl_creatingXid == childXid)
+		if (l->hashsl_owner == CurrentResourceOwner)
 		{
 			if (prev == NULL)
 				HashScans = next;
@@ -101,7 +78,7 @@ _hash_regscan(IndexScanDesc scan)
 
 	new_el = (HashScanList) palloc(sizeof(HashScanListData));
 	new_el->hashsl_scan = scan;
-	new_el->hashsl_creatingXid = GetCurrentTransactionId();
+	new_el->hashsl_owner = CurrentResourceOwner;
 	new_el->hashsl_next = HashScans;
 	HashScans = new_el;
 }

src/backend/access/nbtree/nbtree.c

@@ -12,7 +12,7 @@
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/access/nbtree/nbtree.c,v 1.118 2004/06/05 19:48:07 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/access/nbtree/nbtree.c,v 1.119 2004/07/17 03:27:59 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -58,16 +58,6 @@ static void btbuildCallback(Relation index,
 				void *state);
 
 
-/*
- * AtEOXact_nbtree() --- clean up nbtree subsystem at xact abort or commit.
- */
-void
-AtEOXact_nbtree(void)
-{
-	/* nothing to do at the moment */
-}
-
-
 /*
  *	btbuild() -- build a new btree index.
  *

src/backend/access/rtree/rtscan.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/access/rtree/rtscan.c,v 1.52 2004/07/01 00:49:31 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/access/rtree/rtscan.c,v 1.53 2004/07/17 03:28:17 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -18,6 +18,7 @@
 #include "access/genam.h"
 #include "access/rtree.h"
 #include "utils/lsyscache.h"
+#include "utils/resowner.h"
 
 
 /* routines defined and used here */
@@ -42,7 +43,7 @@ static void adjustiptr(IndexScanDesc s, ItemPointer iptr,
 typedef struct RTScanListData
 {
 	IndexScanDesc rtsl_scan;
-	TransactionId rtsl_creatingXid;
+	ResourceOwner rtsl_owner;
 	struct RTScanListData *rtsl_next;
 } RTScanListData;
 
@@ -241,7 +242,7 @@ rtregscan(IndexScanDesc s)
 
 	l = (RTScanList) palloc(sizeof(RTScanListData));
 	l->rtsl_scan = s;
-	l->rtsl_creatingXid = GetCurrentTransactionId();
+	l->rtsl_owner = CurrentResourceOwner;
 	l->rtsl_next = RTScans;
 	RTScans = l;
 }
@@ -272,52 +273,28 @@ rtdropscan(IndexScanDesc s)
 }
 
 /*
- * AtEOXact_rtree() --- clean up rtree subsystem at xact abort or commit.
+ * ReleaseResources_rtree() --- clean up rtree subsystem resources.
  *
  * This is here because it needs to touch this module's static var RTScans.
  */
 void
-AtEOXact_rtree(void)
-{
-	/*
-	 * Note: these actions should only be necessary during xact abort; but
-	 * they can't hurt during a commit.
-	 */
-
-	/*
-	 * Reset the active-scans list to empty. We do not need to free the
-	 * list elements, because they're all palloc()'d, so they'll go away
-	 * at end of transaction anyway.
-	 */
-	RTScans = NULL;
-}
-
-/*
- * AtEOSubXact_rtree() --- clean up rtree subsystem at subxact abort or commit.
- *
- * This is here because it needs to touch this module's static var RTScans.
- */
-void
-AtEOSubXact_rtree(TransactionId childXid)
+ReleaseResources_rtree(void)
 {
 	RTScanList l;
 	RTScanList prev;
 	RTScanList next;
 
 	/*
-	 * Note: these actions should only be necessary during xact abort; but
-	 * they can't hurt during a commit.
-	 */
-
-	/*
-	 * Forget active scans that were started in this subtransaction.
+	 * Note: this should be a no-op during normal query shutdown.
+	 * However, in an abort situation ExecutorEnd is not called and so
+	 * there may be open index scans to clean up.
 	 */
 	prev = NULL;
 
 	for (l = RTScans; l != NULL; l = next)
 	{
 		next = l->rtsl_next;
-		if (l->rtsl_creatingXid == childXid)
+		if (l->rtsl_owner == CurrentResourceOwner)
 		{
 			if (prev == NULL)
 				RTScans = next;