diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/backend/commands/async.c | 25 |
1 files changed, 13 insertions, 12 deletions
diff --git a/src/backend/commands/async.c b/src/backend/commands/async.c index 333380c22ac..5233e781789 100644 --- a/src/backend/commands/async.c +++ b/src/backend/commands/async.c @@ -7,7 +7,7 @@ * Portions Copyright (c) 1994, Regents of the University of California * * IDENTIFICATION - * $PostgreSQL: pgsql/src/backend/commands/async.c,v 1.109 2004/02/08 22:28:56 neilc Exp $ + * $PostgreSQL: pgsql/src/backend/commands/async.c,v 1.110 2004/05/22 21:58:24 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -52,9 +52,10 @@ * transaction, since by assumption it is only called from outside any * transaction. * - * Although we grab AccessExclusiveLock on pg_listener for any operation, + * Although we grab ExclusiveLock on pg_listener for any operation, * the lock is never held very long, so it shouldn't cause too much of - * a performance problem. + * a performance problem. (Previously we used AccessExclusiveLock, but + * there's no real reason to forbid concurrent reads.) * * An application that listens on the same relname it notifies will get * NOTIFY messages for its own NOTIFYs. These can be ignored, if not useful, @@ -196,7 +197,7 @@ Async_Listen(char *relname, int pid) if (Trace_notify) elog(DEBUG1, "Async_Listen(%s,%d)", relname, pid); - lRel = heap_openr(ListenerRelationName, AccessExclusiveLock); + lRel = heap_openr(ListenerRelationName, ExclusiveLock); /* Detect whether we are already listening on this relname */ scan = heap_beginscan(lRel, SnapshotNow, 0, NULL); @@ -216,7 +217,7 @@ Async_Listen(char *relname, int pid) if (alreadyListener) { - heap_close(lRel, AccessExclusiveLock); + heap_close(lRel, ExclusiveLock); return; } @@ -244,7 +245,7 @@ Async_Listen(char *relname, int pid) heap_freetuple(tuple); - heap_close(lRel, AccessExclusiveLock); + heap_close(lRel, ExclusiveLock); /* * now that we are listening, make sure we will unlisten before dying. @@ -290,7 +291,7 @@ Async_Unlisten(char *relname, int pid) if (Trace_notify) elog(DEBUG1, "Async_Unlisten(%s,%d)", relname, pid); - lRel = heap_openr(ListenerRelationName, AccessExclusiveLock); + lRel = heap_openr(ListenerRelationName, ExclusiveLock); scan = heap_beginscan(lRel, SnapshotNow, 0, NULL); while ((tuple = heap_getnext(scan, ForwardScanDirection)) != NULL) @@ -312,7 +313,7 @@ Async_Unlisten(char *relname, int pid) } heap_endscan(scan); - heap_close(lRel, AccessExclusiveLock); + heap_close(lRel, ExclusiveLock); /* * We do not complain about unlistening something not being listened; @@ -348,7 +349,7 @@ Async_UnlistenAll(void) if (Trace_notify) elog(DEBUG1, "Async_UnlistenAll"); - lRel = heap_openr(ListenerRelationName, AccessExclusiveLock); + lRel = heap_openr(ListenerRelationName, ExclusiveLock); tdesc = RelationGetDescr(lRel); /* Find and delete all entries with my listenerPID */ @@ -362,7 +363,7 @@ Async_UnlistenAll(void) simple_heap_delete(lRel, &lTuple->t_self); heap_endscan(scan); - heap_close(lRel, AccessExclusiveLock); + heap_close(lRel, ExclusiveLock); } /* @@ -457,7 +458,7 @@ AtCommit_Notify(void) value[0] = value[1] = value[2] = (Datum) 0; value[Anum_pg_listener_notify - 1] = Int32GetDatum(MyProcPid); - lRel = heap_openr(ListenerRelationName, AccessExclusiveLock); + lRel = heap_openr(ListenerRelationName, ExclusiveLock); tdesc = RelationGetDescr(lRel); scan = heap_beginscan(lRel, SnapshotNow, 0, NULL); @@ -812,7 +813,7 @@ ProcessIncomingNotify(void) StartTransactionCommand(); - lRel = heap_openr(ListenerRelationName, AccessExclusiveLock); + lRel = heap_openr(ListenerRelationName, ExclusiveLock); tdesc = RelationGetDescr(lRel); /* Scan only entries with my listenerPID */ |