diff options
Diffstat (limited to 'src/backend/storage/lmgr/lmgr.c')
| -rw-r--r-- | src/backend/storage/lmgr/lmgr.c | 72 |
1 files changed, 24 insertions, 48 deletions
diff --git a/src/backend/storage/lmgr/lmgr.c b/src/backend/storage/lmgr/lmgr.c index 6105a3248ce..659c3381e0a 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 1.50 2001/08/25 18:52:42 tgl Exp $ + * $Header: /cvsroot/pgsql/src/backend/storage/lmgr/lmgr.c,v 1.51 2001/09/27 16:29:12 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -145,9 +145,6 @@ LockRelation(Relation relation, LOCKMODE lockmode) { LOCKTAG tag; - if (LockingDisabled()) - return; - MemSet(&tag, 0, sizeof(tag)); tag.relId = relation->rd_lockInfo.lockRelId.relId; tag.dbId = relation->rd_lockInfo.lockRelId.dbId; @@ -182,9 +179,6 @@ ConditionalLockRelation(Relation relation, LOCKMODE lockmode) { LOCKTAG tag; - if (LockingDisabled()) - return true; - MemSet(&tag, 0, sizeof(tag)); tag.relId = relation->rd_lockInfo.lockRelId.relId; tag.dbId = relation->rd_lockInfo.lockRelId.dbId; @@ -215,9 +209,6 @@ UnlockRelation(Relation relation, LOCKMODE lockmode) { LOCKTAG tag; - if (LockingDisabled()) - return; - MemSet(&tag, 0, sizeof(tag)); tag.relId = relation->rd_lockInfo.lockRelId.relId; tag.dbId = relation->rd_lockInfo.lockRelId.dbId; @@ -243,9 +234,6 @@ LockRelationForSession(LockRelId *relid, LOCKMODE lockmode) { LOCKTAG tag; - if (LockingDisabled()) - return; - MemSet(&tag, 0, sizeof(tag)); tag.relId = relid->relId; tag.dbId = relid->dbId; @@ -264,9 +252,6 @@ UnlockRelationForSession(LockRelId *relid, LOCKMODE lockmode) { LOCKTAG tag; - if (LockingDisabled()) - return; - MemSet(&tag, 0, sizeof(tag)); tag.relId = relid->relId; tag.dbId = relid->dbId; @@ -277,15 +262,16 @@ UnlockRelationForSession(LockRelId *relid, LOCKMODE lockmode) /* * LockPage + * + * Obtain a page-level lock. This is currently used by some index access + * methods to lock index pages. For heap relations, it is used only with + * blkno == 0 to signify locking the relation for extension. */ void LockPage(Relation relation, BlockNumber blkno, LOCKMODE lockmode) { LOCKTAG tag; - if (LockingDisabled()) - return; - MemSet(&tag, 0, sizeof(tag)); tag.relId = relation->rd_lockInfo.lockRelId.relId; tag.dbId = relation->rd_lockInfo.lockRelId.dbId; @@ -304,9 +290,6 @@ UnlockPage(Relation relation, BlockNumber blkno, LOCKMODE lockmode) { LOCKTAG tag; - if (LockingDisabled()) - return; - MemSet(&tag, 0, sizeof(tag)); tag.relId = relation->rd_lockInfo.lockRelId.relId; tag.dbId = relation->rd_lockInfo.lockRelId.dbId; @@ -315,14 +298,21 @@ UnlockPage(Relation relation, BlockNumber blkno, LOCKMODE lockmode) LockRelease(LockTableId, &tag, GetCurrentTransactionId(), lockmode); } +/* + * XactLockTableInsert + * + * Insert a lock showing that the given transaction ID is running --- + * this is done during xact startup. The lock can then be used to wait + * for the transaction to finish. + * + * We need no corresponding unlock function, since the lock will always + * be released implicitly at transaction commit/abort, never any other way. + */ void XactLockTableInsert(TransactionId xid) { LOCKTAG tag; - if (LockingDisabled()) - return; - MemSet(&tag, 0, sizeof(tag)); tag.relId = XactLockTableId; tag.dbId = InvalidOid; /* xids are globally unique */ @@ -333,43 +323,29 @@ XactLockTableInsert(TransactionId xid) elog(ERROR, "XactLockTableInsert: LockAcquire failed"); } -#ifdef NOT_USED -void -XactLockTableDelete(TransactionId xid) -{ - LOCKTAG tag; - - if (LockingDisabled()) - return; - - MemSet(&tag, 0, sizeof(tag)); - tag.relId = XactLockTableId; - tag.dbId = InvalidOid; - tag.objId.xid = xid; - - LockRelease(LockTableId, &tag, xid, ExclusiveLock); -} - -#endif - +/* + * XactLockTableWait + * + * Wait for the specified transaction to commit or abort. + */ void XactLockTableWait(TransactionId xid) { LOCKTAG tag; + TransactionId myxid = GetCurrentTransactionId(); - if (LockingDisabled()) - return; + Assert(! TransactionIdEquals(xid, myxid)); MemSet(&tag, 0, sizeof(tag)); tag.relId = XactLockTableId; tag.dbId = InvalidOid; tag.objId.xid = xid; - if (!LockAcquire(LockTableId, &tag, GetCurrentTransactionId(), + if (!LockAcquire(LockTableId, &tag, myxid, ShareLock, false)) elog(ERROR, "XactLockTableWait: LockAcquire failed"); - LockRelease(LockTableId, &tag, GetCurrentTransactionId(), ShareLock); + LockRelease(LockTableId, &tag, myxid, ShareLock); /* * Transaction was committed/aborted/crashed - we have to update |