diff options
| -rw-r--r-- | src/backend/storage/lmgr/lock.c | 29 |
1 files changed, 25 insertions, 4 deletions
diff --git a/src/backend/storage/lmgr/lock.c b/src/backend/storage/lmgr/lock.c index 49dadd181c4..5f2239f4bf0 100644 --- a/src/backend/storage/lmgr/lock.c +++ b/src/backend/storage/lmgr/lock.c @@ -1017,6 +1017,12 @@ LockAcquireExtended(const LOCKTAG *locktag, /* * Find or create LOCK and PROCLOCK objects as needed for a new lock * request. + * + * Returns the PROCLOCK object, or NULL if we failed to create the objects + * for lack of shared memory. + * + * The appropriate partition lock must be held at entry, and will be + * held at exit. */ static PROCLOCK * SetupLockInTable(LockMethod lockMethodTable, PGPROC *proc, @@ -2414,6 +2420,8 @@ FastPathUnGrantRelationLock(Oid relid, LOCKMODE lockmode) * FastPathTransferRelationLocks * Transfer locks matching the given lock tag from per-backend fast-path * arrays to the shared hash table. + * + * Returns true if successful, false if ran out of shared memory. */ static bool FastPathTransferRelationLocks(LockMethod lockMethodTable, const LOCKTAG *locktag, @@ -2529,6 +2537,7 @@ FastPathGetRelationLockEntry(LOCALLOCK *locallock) locallock->hashcode, lockmode); if (!proclock) { + LWLockRelease(partitionLock); ereport(ERROR, (errcode(ERRCODE_OUT_OF_MEMORY), errmsg("out of shared memory"), @@ -3422,9 +3431,6 @@ GetRunningTransactionLocks(int *nlocks) for (i = 0; i < NUM_LOCK_PARTITIONS; i++) LWLockAcquire(FirstLockMgrLock + i, LW_SHARED); - /* Now scan the tables to copy the data */ - hash_seq_init(&seqstat, LockMethodProcLockHash); - /* Now we can safely count the number of proclocks */ els = hash_get_num_entries(LockMethodProcLockHash); @@ -3434,6 +3440,9 @@ GetRunningTransactionLocks(int *nlocks) */ accessExclusiveLocks = palloc(els * sizeof(xl_standby_lock)); + /* Now scan the tables to copy the data */ + hash_seq_init(&seqstat, LockMethodProcLockHash); + /* * If lock is a currently granted AccessExclusiveLock then it will have * just one proclock holder, so locks are never accessed twice in this @@ -3978,22 +3987,34 @@ VirtualXactLock(VirtualTransactionId vxid, bool wait) /* * OK, we're going to need to sleep on the VXID. But first, we must set - * up the primary lock table entry, if needed. + * up the primary lock table entry, if needed (ie, convert the proc's + * fast-path lock on its VXID to a regular lock). */ if (proc->fpVXIDLock) { PROCLOCK *proclock; uint32 hashcode; + LWLockId partitionLock; hashcode = LockTagHashCode(&tag); + + partitionLock = LockHashPartitionLock(hashcode); + LWLockAcquire(partitionLock, LW_EXCLUSIVE); + proclock = SetupLockInTable(LockMethods[DEFAULT_LOCKMETHOD], proc, &tag, hashcode, ExclusiveLock); if (!proclock) + { + LWLockRelease(partitionLock); ereport(ERROR, (errcode(ERRCODE_OUT_OF_MEMORY), errmsg("out of shared memory"), errhint("You might need to increase max_locks_per_transaction."))); + } GrantLock(proclock->tag.myLock, proclock, ExclusiveLock); + + LWLockRelease(partitionLock); + proc->fpVXIDLock = false; } |