diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/backend/storage/lmgr/predicate.c | 18 | ||||
| -rw-r--r-- | src/include/storage/predicate_internals.h | 5 |
2 files changed, 17 insertions, 6 deletions
diff --git a/src/backend/storage/lmgr/predicate.c b/src/backend/storage/lmgr/predicate.c index 5ac76249910..6facb533e0f 100644 --- a/src/backend/storage/lmgr/predicate.c +++ b/src/backend/storage/lmgr/predicate.c @@ -245,6 +245,11 @@ #define SxactIsReadOnly(sxact) (((sxact)->flags & SXACT_FLAG_READ_ONLY) != 0) #define SxactHasSummaryConflictIn(sxact) (((sxact)->flags & SXACT_FLAG_SUMMARY_CONFLICT_IN) != 0) #define SxactHasSummaryConflictOut(sxact) (((sxact)->flags & SXACT_FLAG_SUMMARY_CONFLICT_OUT) != 0) +/* + * The following macro actually means that the specified transaction has a + * conflict out *to a transaction which committed ahead of it*. It's hard + * to get that into a name of a reasonable length. + */ #define SxactHasConflictOut(sxact) (((sxact)->flags & SXACT_FLAG_CONFLICT_OUT) != 0) #define SxactIsDeferrableWaiting(sxact) (((sxact)->flags & SXACT_FLAG_DEFERRABLE_WAITING) != 0) #define SxactIsROSafe(sxact) (((sxact)->flags & SXACT_FLAG_RO_SAFE) != 0) @@ -2708,7 +2713,7 @@ SetNewSxactGlobalXmin(void) * up in some relatively timely fashion. * * If this transaction is committing and is holding any predicate locks, - * it must be added to a list of completed serializable transaction still + * it must be added to a list of completed serializable transactions still * holding locks. */ void @@ -2753,12 +2758,13 @@ ReleasePredicateLocks(const bool isCommit) LWLockAcquire(SerializableXactHashLock, LW_EXCLUSIVE); /* - * We don't hold a lock here, assuming that TransactionId is atomic! + * We don't hold XidGenLock lock here, assuming that TransactionId is + * atomic! * * If this value is changing, we don't care that much whether we get the * old or new value -- it is just used to determine how far - * GlobalSerizableXmin must advance before this transaction can be cleaned - * fully cleaned up. The worst that could happen is we wait for ome more + * GlobalSerizableXmin must advance before this transaction can be fully + * cleaned up. The worst that could happen is we wait for one more * transaction to complete before freeing some RAM; correctness of visible * behavior is not affected. */ @@ -3860,8 +3866,8 @@ OnConflict_CheckForSerializationFailure(const SERIALIZABLEXACT *reader, * Because T2 must've committed first, there is no anomaly if: * - the reader committed before T2 * - the writer committed before T2 - * - the reader is a READ ONLY transaction and the reader was not - * concurrent with T2 (= reader acquired its snapshot after T2 committed) + * - the reader is a READ ONLY transaction and the reader was concurrent + * with T2 (= reader acquired its snapshot before T2 committed) */ if (!failure) { diff --git a/src/include/storage/predicate_internals.h b/src/include/storage/predicate_internals.h index bd42004c2cd..b144ab319ae 100644 --- a/src/include/storage/predicate_internals.h +++ b/src/include/storage/predicate_internals.h @@ -92,6 +92,11 @@ typedef struct SERIALIZABLEXACT #define SXACT_FLAG_ROLLED_BACK 0x00000001 #define SXACT_FLAG_COMMITTED 0x00000002 +/* + * The following flag actually means that the flagged transaction has a + * conflict out *to a transaction which committed ahead of it*. It's hard + * to get that into a name of a reasonable length. + */ #define SXACT_FLAG_CONFLICT_OUT 0x00000004 #define SXACT_FLAG_READ_ONLY 0x00000008 #define SXACT_FLAG_DID_WRITE 0x00000010 |