diff options
Diffstat (limited to 'src/backend/storage/lmgr/predicate.c')
| -rw-r--r-- | src/backend/storage/lmgr/predicate.c | 20 |
1 files changed, 16 insertions, 4 deletions
diff --git a/src/backend/storage/lmgr/predicate.c b/src/backend/storage/lmgr/predicate.c index 25e7e4e37bf..86ca2cac972 100644 --- a/src/backend/storage/lmgr/predicate.c +++ b/src/backend/storage/lmgr/predicate.c @@ -3333,6 +3333,7 @@ SetNewSxactGlobalXmin(void) void ReleasePredicateLocks(bool isCommit, bool isReadOnlySafe) { + bool partiallyReleasing = false; bool needToClear; RWConflict conflict, nextConflict, @@ -3433,6 +3434,7 @@ ReleasePredicateLocks(bool isCommit, bool isReadOnlySafe) else { MySerializableXact->flags |= SXACT_FLAG_PARTIALLY_RELEASED; + partiallyReleasing = true; /* ... and proceed to perform the partial release below. */ } } @@ -3683,9 +3685,15 @@ ReleasePredicateLocks(bool isCommit, bool isReadOnlySafe) * serializable transactions completes. We then find the "new oldest" * xmin and purge any transactions which finished before this transaction * was launched. + * + * For parallel queries in read-only transactions, it might run twice. + * We only release the reference on the first call. */ needToClear = false; - if (TransactionIdEquals(MySerializableXact->xmin, PredXact->SxactGlobalXmin)) + if ((partiallyReleasing || + !SxactIsPartiallyReleased(MySerializableXact)) && + TransactionIdEquals(MySerializableXact->xmin, + PredXact->SxactGlobalXmin)) { Assert(PredXact->SxactGlobalXminCount > 0); if (--(PredXact->SxactGlobalXminCount) == 0) @@ -4841,10 +4849,14 @@ PreCommit_CheckForSerializationFailure(void) LWLockAcquire(SerializableXactHashLock, LW_EXCLUSIVE); - /* Check if someone else has already decided that we need to die */ - if (SxactIsDoomed(MySerializableXact)) + /* + * Check if someone else has already decided that we need to die. Since + * we set our own DOOMED flag when partially releasing, ignore in that + * case. + */ + if (SxactIsDoomed(MySerializableXact) && + !SxactIsPartiallyReleased(MySerializableXact)) { - Assert(!SxactIsPartiallyReleased(MySerializableXact)); LWLockRelease(SerializableXactHashLock); ereport(ERROR, (errcode(ERRCODE_T_R_SERIALIZATION_FAILURE), |