3 files changed, 38 insertions, 29 deletions
diff --git a/src/backend/access/nbtree/nbtree.c b/src/backend/access/nbtree/nbtree.c
index 80db5170162..5cc42e9abc1 100644
--- a/src/backend/access/nbtree/nbtree.c
+++ b/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 1.153 2006/11/01 19:43:17 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/access/nbtree/nbtree.c,v 1.153.2.1 2008/04/17 00:00:00 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -23,6 +23,7 @@
 #include "catalog/index.h"
 #include "commands/vacuum.h"
 #include "storage/freespace.h"
+#include "storage/ipc.h"
 #include "storage/lmgr.h"
 #include "utils/memutils.h"
 
@@ -538,21 +539,15 @@ btbulkdelete(PG_FUNCTION_ARGS)
 		stats = (IndexBulkDeleteResult *) palloc0(sizeof(IndexBulkDeleteResult));
 
 	/* Establish the vacuum cycle ID to use for this scan */
-	PG_TRY();
+	/* The ENSURE stuff ensures we clean up shared memory on failure */
+	PG_ENSURE_ERROR_CLEANUP(_bt_end_vacuum_callback, PointerGetDatum(rel));
 	{
 		cycleid = _bt_start_vacuum(rel);
 
 		btvacuumscan(info, stats, callback, callback_state, cycleid);
-
-		_bt_end_vacuum(rel);
-	}
-	PG_CATCH();
-	{
-		/* Make sure shared memory gets cleaned up */
-		_bt_end_vacuum(rel);
-		PG_RE_THROW();
 	}
-	PG_END_TRY();
+	PG_END_ENSURE_ERROR_CLEANUP(_bt_end_vacuum_callback, PointerGetDatum(rel));
+	_bt_end_vacuum(rel);
 
 	PG_RETURN_POINTER(stats);
 }
diff --git a/src/backend/access/nbtree/nbtutils.c b/src/backend/access/nbtree/nbtutils.c
index 47abb5750dd..0ea2df817c0 100644
--- a/src/backend/access/nbtree/nbtutils.c
+++ b/src/backend/access/nbtree/nbtutils.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/access/nbtree/nbtutils.c,v 1.79.2.1 2007/03/30 00:13:05 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/access/nbtree/nbtutils.c,v 1.79.2.2 2008/04/17 00:00:00 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -974,8 +974,11 @@ _bt_vacuum_cycleid(Relation rel)
 /*
  * _bt_start_vacuum --- assign a cycle ID to a just-starting VACUUM operation
  *
- * Note: the caller must guarantee (via PG_TRY) that it will eventually call
- * _bt_end_vacuum, else we'll permanently leak an array slot.
+ * Note: the caller must guarantee that it will eventually call
+ * _bt_end_vacuum, else we'll permanently leak an array slot.  To ensure
+ * that this happens even in elog(FATAL) scenarios, the appropriate coding
+ * is not just a PG_TRY, but
+ *		PG_ENSURE_ERROR_CLEANUP(_bt_end_vacuum_callback, PointerGetDatum(rel))
  */
 BTCycleId
 _bt_start_vacuum(Relation rel)
@@ -1058,6 +1061,15 @@ _bt_end_vacuum(Relation rel)
 }
 
 /*
+ * _bt_end_vacuum wrapped as an on_shmem_exit callback function
+ */
+void
+_bt_end_vacuum_callback(int code, Datum arg)
+{
+	_bt_end_vacuum((Relation) DatumGetPointer(arg));
+}
+
+/*
  * BTreeShmemSize --- report amount of shared memory space needed
  */
 Size
diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c
index 63500b304a8..3f9383e8697 100644
--- a/src/backend/access/transam/xlog.c
+++ b/src/backend/access/transam/xlog.c
@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1996-2006, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/backend/access/transam/xlog.c,v 1.258.2.2 2007/09/29 01:36:19 tgl Exp $
+ * $PostgreSQL: pgsql/src/backend/access/transam/xlog.c,v 1.258.2.3 2008/04/17 00:00:00 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -41,6 +41,7 @@
 #include "postmaster/bgwriter.h"
 #include "storage/bufpage.h"
 #include "storage/fd.h"
+#include "storage/ipc.h"
 #include "storage/pmsignal.h"
 #include "storage/procarray.h"
 #include "storage/spin.h"
@@ -501,11 +502,11 @@ static void writeTimeLineHistory(TimeLineID newTLI, TimeLineID parentTLI,
 static void WriteControlFile(void);
 static void ReadControlFile(void);
 static char *str_time(time_t tnow);
-static void issue_xlog_fsync(void);
-
 #ifdef WAL_DEBUG
 static void xlog_outrec(StringInfo buf, XLogRecord *record);
 #endif
+static void issue_xlog_fsync(void);
+static void pg_start_backup_callback(int code, Datum arg);
 static bool read_backup_label(XLogRecPtr *checkPointLoc,
 				  XLogRecPtr *minRecoveryLoc);
 static void rm_redo_error_callback(void *arg);
@@ -6185,8 +6186,8 @@ pg_start_backup(PG_FUNCTION_ARGS)
 	XLogCtl->Insert.forcePageWrites = true;
 	LWLockRelease(WALInsertLock);
 
-	/* Use a TRY block to ensure we release forcePageWrites if fail below */
-	PG_TRY();
+	/* Ensure we release forcePageWrites if fail below */
+	PG_ENSURE_ERROR_CLEANUP(pg_start_backup_callback, (Datum) 0);
 	{
 		/*
 		 * Force a CHECKPOINT.	Aside from being necessary to prevent torn
@@ -6261,16 +6262,7 @@ pg_start_backup(PG_FUNCTION_ARGS)
 					 errmsg("could not write file \"%s\": %m",
 							BACKUP_LABEL_FILE)));
 	}
-	PG_CATCH();
-	{
-		/* Turn off forcePageWrites on failure */
-		LWLockAcquire(WALInsertLock, LW_EXCLUSIVE);
-		XLogCtl->Insert.forcePageWrites = false;
-		LWLockRelease(WALInsertLock);
-
-		PG_RE_THROW();
-	}
-	PG_END_TRY();
+	PG_END_ENSURE_ERROR_CLEANUP(pg_start_backup_callback, (Datum) 0);
 
 	/*
 	 * We're done.  As a convenience, return the starting WAL location.
@@ -6282,6 +6274,16 @@ pg_start_backup(PG_FUNCTION_ARGS)
 	PG_RETURN_TEXT_P(result);
 }
 
+/* Error cleanup callback for pg_start_backup */
+static void
+pg_start_backup_callback(int code, Datum arg)
+{
+	/* Turn off forcePageWrites on failure */
+	LWLockAcquire(WALInsertLock, LW_EXCLUSIVE);
+	XLogCtl->Insert.forcePageWrites = false;
+	LWLockRelease(WALInsertLock);
+}
+
 /*
  * pg_stop_backup: finish taking an on-line backup dump
  *