diff options
Diffstat (limited to 'src/backend/commands/waitlsn.c')
| -rw-r--r-- | src/backend/commands/waitlsn.c | 10 |
1 files changed, 8 insertions, 2 deletions
diff --git a/src/backend/commands/waitlsn.c b/src/backend/commands/waitlsn.c index a57b818a2d4..1a83c34e09f 100644 --- a/src/backend/commands/waitlsn.c +++ b/src/backend/commands/waitlsn.c @@ -109,13 +109,13 @@ addLSNWaiter(XLogRecPtr lsn) { WaitLSNProcInfo *procInfo = &waitLSN->procInfos[MyProcNumber]; + LWLockAcquire(WaitLSNLock, LW_EXCLUSIVE); + Assert(!procInfo->inHeap); procInfo->procnum = MyProcNumber; procInfo->waitLSN = lsn; - LWLockAcquire(WaitLSNLock, LW_EXCLUSIVE); - pairingheap_add(&waitLSN->waitersHeap, &procInfo->phNode); procInfo->inHeap = true; updateMinWaitedLSN(); @@ -203,6 +203,12 @@ WaitLSNSetLatches(XLogRecPtr currentLSN) void WaitLSNCleanup(void) { + /* + * We do a fast-path check of the 'inHeap' flag without the lock. This + * flag is set to true only by the process itself. So, it's only possible + * to get a false positive. But that will be eliminated by a recheck + * inside deleteLSNWaiter(). + */ if (waitLSN->procInfos[MyProcNumber].inHeap) deleteLSNWaiter(); } |