diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/backend/storage/lmgr/predicate.c | 26 |
1 files changed, 23 insertions, 3 deletions
diff --git a/src/backend/storage/lmgr/predicate.c b/src/backend/storage/lmgr/predicate.c index 821328b220b..9e927f85644 100644 --- a/src/backend/storage/lmgr/predicate.c +++ b/src/backend/storage/lmgr/predicate.c @@ -3528,10 +3528,29 @@ ClearOldPredicateLocks(void) else if (finishedSxact->commitSeqNo > PredXact->HavePartialClearedThrough && finishedSxact->commitSeqNo <= PredXact->CanPartialClearThrough) { + /* + * Any active transactions that took their snapshot before this + * transaction committed are read-only, so we can clear part of + * its state. + */ LWLockRelease(SerializableXactHashLock); - ReleaseOneSerializableXact(finishedSxact, - !SxactIsReadOnly(finishedSxact), - false); + + if (SxactIsReadOnly(finishedSxact)) + { + /* A read-only transaction can be removed entirely */ + SHMQueueDelete(&(finishedSxact->finishedLink)); + ReleaseOneSerializableXact(finishedSxact, false, false); + } + else + { + /* + * A read-write transaction can only be partially + * cleared. We need to keep the SERIALIZABLEXACT but + * can release the SIREAD locks and conflicts in. + */ + ReleaseOneSerializableXact(finishedSxact, true, false); + } + PredXact->HavePartialClearedThrough = finishedSxact->commitSeqNo; LWLockAcquire(SerializableXactHashLock, LW_SHARED); } @@ -3637,6 +3656,7 @@ ReleaseOneSerializableXact(SERIALIZABLEXACT *sxact, bool partial, Assert(sxact != NULL); Assert(SxactIsRolledBack(sxact) || SxactIsCommitted(sxact)); + Assert(partial || !SxactIsOnFinishedList(sxact)); Assert(LWLockHeldByMe(SerializableFinishedListLock)); /* |