diff options
Diffstat (limited to 'src/backend/storage/lmgr/lock.c')
| -rw-r--r-- | src/backend/storage/lmgr/lock.c | 14 |
1 files changed, 9 insertions, 5 deletions
diff --git a/src/backend/storage/lmgr/lock.c b/src/backend/storage/lmgr/lock.c index 2f822add66..4c38764374 100644 --- a/src/backend/storage/lmgr/lock.c +++ b/src/backend/storage/lmgr/lock.c @@ -7,7 +7,7 @@ * * * IDENTIFICATION - * $Header: /cvsroot/pgsql/src/backend/storage/lmgr/lock.c,v 1.46 1999/03/06 21:17:44 tgl Exp $ + * $Header: /cvsroot/pgsql/src/backend/storage/lmgr/lock.c,v 1.47 1999/04/30 02:04:50 momjian Exp $ * * NOTES * Outside modules can create a lock table and acquire/release @@ -820,13 +820,17 @@ LockResolveConflicts(LOCKMETHOD lockmethod, /* ------------------------ * If someone with a greater priority is waiting for the lock, * do not continue and share the lock, even if we can. bjm + * Don't do this if the process already has some locks, because + * this could hold up other people waiting on our locks, causing + * a priority inversion. bjm * ------------------------ */ int myprio = LockMethodTable[lockmethod]->ctl->prio[lockmode]; PROC_QUEUE *waitQueue = &(lock->waitProcs); PROC *topproc = (PROC *) MAKE_PTR(waitQueue->links.prev); - if (waitQueue->size && topproc->prio > myprio) + if (SHMQueueEmpty(lockQueue) && waitQueue->size && + topproc->prio > myprio) { XID_PRINT("LockResolveConflicts: higher priority proc waiting", result); @@ -1595,7 +1599,7 @@ DeadLockCheck(SHM_QUEUE *lockQueue, LOCK *findlock, bool skip_check) * * The lock we are waiting for is already in MyProc->lockQueue so we * need to skip it here. We are trying to find it in someone - * else's lockQueue. + * else's lockQueue. bjm */ if (lock == findlock && !skip_check) return true; @@ -1625,7 +1629,7 @@ DeadLockCheck(SHM_QUEUE *lockQueue, LOCK *findlock, bool skip_check) * * Basically, the test is, "Do we both hold some lock on * findlock, and we are both waiting in the lock - * queue?" + * queue?" bjm */ Assert(skip_check); @@ -1672,7 +1676,7 @@ DeadLockCheck(SHM_QUEUE *lockQueue, LOCK *findlock, bool skip_check) * hold locks and are waiting. Now we check for * cases where we have two or more tables in a * deadlock. We do this by continuing to search - * for someone holding a lock + * for someone holding a lock bjm */ if (DeadLockCheck(&(proc->lockQueue), findlock, false)) return true; |