diff options
Diffstat (limited to 'src/backend/utils/time/snapmgr.c')
| -rw-r--r-- | src/backend/utils/time/snapmgr.c | 38 |
1 files changed, 18 insertions, 20 deletions
diff --git a/src/backend/utils/time/snapmgr.c b/src/backend/utils/time/snapmgr.c index 9802fa7ded7..2834753d734 100644 --- a/src/backend/utils/time/snapmgr.c +++ b/src/backend/utils/time/snapmgr.c @@ -11,7 +11,7 @@ * regd_count and count it in RegisteredSnapshots, but this reference is not * tracked by a resource owner. We used to use the TopTransactionResourceOwner * to track this snapshot reference, but that introduces logical circularity - * and thus makes it impossible to clean up in a sane fashion. It's better to + * and thus makes it impossible to clean up in a sane fashion. It's better to * handle this reference as an internally-tracked registration, so that this * module is entirely lower-level than ResourceOwners. * @@ -24,9 +24,9 @@ * transaction). * * These arrangements let us reset MyPgXact->xmin when there are no snapshots - * referenced by this transaction. (One possible improvement would be to be + * referenced by this transaction. (One possible improvement would be to be * able to advance Xmin when the snapshot with the earliest Xmin is no longer - * referenced. That's a bit harder though, it requires more locking, and + * referenced. That's a bit harder though, it requires more locking, and * anyway it should be rather uncommon to keep temporary snapshots referenced * for too long.) * @@ -63,7 +63,7 @@ * CurrentSnapshot points to the only snapshot taken in transaction-snapshot * mode, and to the latest one taken in a read-committed transaction. * SecondarySnapshot is a snapshot that's always up-to-date as of the current - * instant, even in transaction-snapshot mode. It should only be used for + * instant, even in transaction-snapshot mode. It should only be used for * special-purpose code (say, RI checking.) CatalogSnapshot points to an * MVCC snapshot intended to be used for catalog scans; we must refresh it * whenever a system catalog change occurs. @@ -135,7 +135,7 @@ static int RegisteredSnapshots = 0; bool FirstSnapshotSet = false; /* - * Remember the serializable transaction snapshot, if any. We cannot trust + * Remember the serializable transaction snapshot, if any. We cannot trust * FirstSnapshotSet in combination with IsolationUsesXactSnapshot(), because * GUC may be reset before us, changing the value of IsolationUsesXactSnapshot. */ @@ -169,9 +169,9 @@ Snapshot GetTransactionSnapshot(void) { /* - * Return historic snapshot if doing logical decoding. We'll never - * need a non-historic transaction snapshot in this (sub-)transaction, so - * there's no need to be careful to set one up for later calls to + * Return historic snapshot if doing logical decoding. We'll never need a + * non-historic transaction snapshot in this (sub-)transaction, so there's + * no need to be careful to set one up for later calls to * GetTransactionSnapshot(). */ if (HistoricSnapshotActive()) @@ -238,8 +238,7 @@ GetLatestSnapshot(void) { /* * So far there are no cases requiring support for GetLatestSnapshot() - * during logical decoding, but it wouldn't be hard to add if - * required. + * during logical decoding, but it wouldn't be hard to add if required. */ Assert(!HistoricSnapshotActive()); @@ -283,12 +282,11 @@ Snapshot GetNonHistoricCatalogSnapshot(Oid relid) { /* - * If the caller is trying to scan a relation that has no syscache, - * no catcache invalidations will be sent when it is updated. For a - * a few key relations, snapshot invalidations are sent instead. If - * we're trying to scan a relation for which neither catcache nor - * snapshot invalidations are sent, we must refresh the snapshot every - * time. + * If the caller is trying to scan a relation that has no syscache, no + * catcache invalidations will be sent when it is updated. For a a few + * key relations, snapshot invalidations are sent instead. If we're + * trying to scan a relation for which neither catcache nor snapshot + * invalidations are sent, we must refresh the snapshot every time. */ if (!CatalogSnapshotStale && !RelationInvalidatesSnapshotsOnly(relid) && !RelationHasSysCache(relid)) @@ -403,7 +401,7 @@ SetTransactionSnapshot(Snapshot sourcesnap, TransactionId sourcexid) /* * In transaction-snapshot mode, the first snapshot must live until end of - * xact, so we must make a copy of it. Furthermore, if we're running in + * xact, so we must make a copy of it. Furthermore, if we're running in * serializable mode, predicate.c needs to do its own processing. */ if (IsolationUsesXactSnapshot()) @@ -499,7 +497,7 @@ FreeSnapshot(Snapshot snapshot) * * If the passed snapshot is a statically-allocated one, or it is possibly * subject to a future command counter update, create a new long-lived copy - * with active refcount=1. Otherwise, only increment the refcount. + * with active refcount=1. Otherwise, only increment the refcount. */ void PushActiveSnapshot(Snapshot snap) @@ -868,7 +866,7 @@ ExportSnapshot(Snapshot snapshot) * However, we haven't got enough information to do that, since we don't * know if we're at top level or not. For example, we could be inside a * plpgsql function that is going to fire off other transactions via - * dblink. Rather than disallow perfectly legitimate usages, don't make a + * dblink. Rather than disallow perfectly legitimate usages, don't make a * check. * * Also note that we don't make any restriction on the transaction's @@ -1081,7 +1079,7 @@ parseXidFromText(const char *prefix, char **s, const char *filename) /* * ImportSnapshot - * Import a previously exported snapshot. The argument should be a + * Import a previously exported snapshot. The argument should be a * filename in SNAPSHOT_EXPORT_DIR. Load the snapshot from that file. * This is called by "SET TRANSACTION SNAPSHOT 'foo'". */ |