diff options
Diffstat (limited to 'src/backend/storage/lmgr/lmgr.c')
| -rw-r--r-- | src/backend/storage/lmgr/lmgr.c | 28 |
1 files changed, 25 insertions, 3 deletions
diff --git a/src/backend/storage/lmgr/lmgr.c b/src/backend/storage/lmgr/lmgr.c index fe5acacbf5e..5107975ace3 100644 --- a/src/backend/storage/lmgr/lmgr.c +++ b/src/backend/storage/lmgr/lmgr.c @@ -8,7 +8,7 @@ * * * IDENTIFICATION - * $Header: /cvsroot/pgsql/src/backend/storage/lmgr/lmgr.c,v 1.58 2003/08/04 02:40:03 momjian Exp $ + * $Header: /cvsroot/pgsql/src/backend/storage/lmgr/lmgr.c,v 1.58.2.1 2003/09/07 04:36:53 momjian Exp $ * *------------------------------------------------------------------------- */ @@ -76,8 +76,10 @@ InitLockTable(int maxBackends) { int lockmethod; + /* number of lock modes is lengthof()-1 because of dummy zero */ lockmethod = LockMethodTableInit("LockTable", - LockConflicts, MAX_LOCKMODES - 1, + LockConflicts, + lengthof(LockConflicts) - 1, maxBackends); LockTableId = lockmethod; @@ -151,7 +153,7 @@ LockRelation(Relation relation, LOCKMODE lockmode) * As above, but only lock if we can get the lock without blocking. * Returns TRUE iff the lock was acquired. * - * NOTE: we do not currently need conditional versions of the other + * NOTE: we do not currently need conditional versions of all the * LockXXX routines in this file, but they could easily be added if needed. */ bool @@ -263,6 +265,26 @@ LockPage(Relation relation, BlockNumber blkno, LOCKMODE lockmode) } /* + * ConditionalLockPage + * + * As above, but only lock if we can get the lock without blocking. + * Returns TRUE iff the lock was acquired. + */ +bool +ConditionalLockPage(Relation relation, BlockNumber blkno, LOCKMODE lockmode) +{ + LOCKTAG tag; + + MemSet(&tag, 0, sizeof(tag)); + tag.relId = relation->rd_lockInfo.lockRelId.relId; + tag.dbId = relation->rd_lockInfo.lockRelId.dbId; + tag.objId.blkno = blkno; + + return LockAcquire(LockTableId, &tag, GetCurrentTransactionId(), + lockmode, true); +} + +/* * UnlockPage */ void |