diff options
Diffstat (limited to 'src/backend/storage/lmgr/lock.c')
| -rw-r--r-- | src/backend/storage/lmgr/lock.c | 50 |
1 files changed, 24 insertions, 26 deletions
diff --git a/src/backend/storage/lmgr/lock.c b/src/backend/storage/lmgr/lock.c index d7180d7c1fd..6f02c0720e2 100644 --- a/src/backend/storage/lmgr/lock.c +++ b/src/backend/storage/lmgr/lock.c @@ -8,7 +8,7 @@ * * * IDENTIFICATION - * $PostgreSQL: pgsql/src/backend/storage/lmgr/lock.c,v 1.153 2005/05/29 04:23:04 tgl Exp $ + * $PostgreSQL: pgsql/src/backend/storage/lmgr/lock.c,v 1.154 2005/05/29 22:45:02 tgl Exp $ * * NOTES * Outside modules can create a lock table and acquire/release @@ -160,8 +160,8 @@ PROCLOCK_PRINT(const char *where, const PROCLOCK *proclockP) static void RemoveLocalLock(LOCALLOCK *locallock); static void GrantLockLocal(LOCALLOCK *locallock, ResourceOwner owner); -static int WaitOnLock(LOCKMETHODID lockmethodid, LOCALLOCK *locallock, - ResourceOwner owner); +static void WaitOnLock(LOCKMETHODID lockmethodid, LOCALLOCK *locallock, + ResourceOwner owner); static void LockCountMyLocks(SHMEM_OFFSET lockOffset, PGPROC *proc, int *myHolding); static bool UnGrantLock(LOCK *lock, LOCKMODE lockmode, @@ -377,11 +377,14 @@ LockMethodTableRename(LOCKMETHODID lockmethodid) * LockAcquire -- Check for lock conflicts, sleep if conflict found, * set lock if/when no conflicts. * - * Returns: TRUE if lock was acquired, FALSE otherwise. Note that - * a FALSE return is to be expected if dontWait is TRUE; - * but if dontWait is FALSE, only a parameter error can cause - * a FALSE return. (XXX probably we should just ereport on parameter - * errors, instead of conflating this with failure to acquire lock?) + * Returns one of: + * LOCKACQUIRE_NOT_AVAIL lock not available, and dontWait=true + * LOCKACQUIRE_OK lock successfully acquired + * LOCKACQUIRE_ALREADY_HELD incremented count for lock already held + * + * In the normal case where dontWait=false and the caller doesn't need to + * distinguish a freshly acquired lock from one already taken earlier in + * this same transaction, there is no need to examine the return value. * * Side Effects: The lock is acquired and recorded in lock tables. * @@ -416,8 +419,7 @@ LockMethodTableRename(LOCKMETHODID lockmethodid) * * DZ - 22 Nov 1997 */ - -bool +LockAcquireResult LockAcquire(LOCKMETHODID lockmethodid, LOCKTAG *locktag, TransactionId xid, LOCKMODE lockmode, bool dontWait) { @@ -447,10 +449,7 @@ LockAcquire(LOCKMETHODID lockmethodid, LOCKTAG *locktag, Assert(lockmethodid < NumLockMethods); lockMethodTable = LockMethods[lockmethodid]; if (!lockMethodTable) - { - elog(WARNING, "bad lock table id: %d", lockmethodid); - return FALSE; - } + elog(ERROR, "unrecognized lock method: %d", lockmethodid); /* Session locks and user locks are not transactional */ if (xid != InvalidTransactionId && @@ -507,7 +506,7 @@ LockAcquire(LOCKMETHODID lockmethodid, LOCKTAG *locktag, if (locallock->nLocks > 0) { GrantLockLocal(locallock, owner); - return TRUE; + return LOCKACQUIRE_ALREADY_HELD; } /* @@ -669,7 +668,7 @@ LockAcquire(LOCKMETHODID lockmethodid, LOCKTAG *locktag, GrantLockLocal(locallock, owner); PROCLOCK_PRINT("LockAcquire: my other XID owning", proclock); LWLockRelease(masterLock); - return TRUE; + return LOCKACQUIRE_ALREADY_HELD; } /* @@ -696,8 +695,8 @@ LockAcquire(LOCKMETHODID lockmethodid, LOCKTAG *locktag, /* * We can't acquire the lock immediately. If caller specified no - * blocking, remove useless table entries and return FALSE without - * waiting. + * blocking, remove useless table entries and return NOT_AVAIL + * without waiting. */ if (dontWait) { @@ -720,7 +719,7 @@ LockAcquire(LOCKMETHODID lockmethodid, LOCKTAG *locktag, LWLockRelease(masterLock); if (locallock->nLocks == 0) RemoveLocalLock(locallock); - return FALSE; + return LOCKACQUIRE_NOT_AVAIL; } /* @@ -740,7 +739,7 @@ LockAcquire(LOCKMETHODID lockmethodid, LOCKTAG *locktag, /* * Sleep till someone wakes me up. */ - status = WaitOnLock(lockmethodid, locallock, owner); + WaitOnLock(lockmethodid, locallock, owner); /* * NOTE: do not do any material change of state between here and @@ -759,7 +758,7 @@ LockAcquire(LOCKMETHODID lockmethodid, LOCKTAG *locktag, LOCK_PRINT("LockAcquire: INCONSISTENT", lock, lockmode); /* Should we retry ? */ LWLockRelease(masterLock); - return FALSE; + elog(ERROR, "LockAcquire failed"); } PROCLOCK_PRINT("LockAcquire: granted", proclock); LOCK_PRINT("LockAcquire: granted", lock, lockmode); @@ -767,7 +766,7 @@ LockAcquire(LOCKMETHODID lockmethodid, LOCKTAG *locktag, LWLockRelease(masterLock); - return status == STATUS_OK; + return LOCKACQUIRE_OK; } /* @@ -1091,7 +1090,7 @@ GrantAwaitedLock(void) * * The locktable's masterLock must be held at entry. */ -static int +static void WaitOnLock(LOCKMETHODID lockmethodid, LOCALLOCK *locallock, ResourceOwner owner) { @@ -1159,7 +1158,6 @@ WaitOnLock(LOCKMETHODID lockmethodid, LOCALLOCK *locallock, LOCK_PRINT("WaitOnLock: wakeup on lock", locallock->lock, locallock->tag.mode); - return STATUS_OK; } /* @@ -1247,7 +1245,7 @@ LockRelease(LOCKMETHODID lockmethodid, LOCKTAG *locktag, Assert(lockmethodid < NumLockMethods); lockMethodTable = LockMethods[lockmethodid]; if (!lockMethodTable) - elog(ERROR, "bad lock method: %d", lockmethodid); + elog(ERROR, "unrecognized lock method: %d", lockmethodid); /* * Find the LOCALLOCK entry for this lock and lockmode @@ -1397,7 +1395,7 @@ LockReleaseAll(LOCKMETHODID lockmethodid, bool allxids) Assert(lockmethodid < NumLockMethods); lockMethodTable = LockMethods[lockmethodid]; if (!lockMethodTable) - elog(ERROR, "bad lock method: %d", lockmethodid); + elog(ERROR, "unrecognized lock method: %d", lockmethodid); numLockModes = lockMethodTable->numLockModes; masterLock = lockMethodTable->masterLock; |