diff options
Diffstat (limited to 'src/backend/utils')
| -rw-r--r-- | src/backend/utils/adt/ri_triggers.c | 10 | ||||
| -rw-r--r-- | src/backend/utils/time/tqual.c | 89 |
2 files changed, 57 insertions, 42 deletions
diff --git a/src/backend/utils/adt/ri_triggers.c b/src/backend/utils/adt/ri_triggers.c index 72200ced9dc..af363f4acff 100644 --- a/src/backend/utils/adt/ri_triggers.c +++ b/src/backend/utils/adt/ri_triggers.c @@ -15,7 +15,7 @@ * * Portions Copyright (c) 1996-2007, PostgreSQL Global Development Group * - * $PostgreSQL: pgsql/src/backend/utils/adt/ri_triggers.c,v 1.92 2007/03/15 23:12:06 tgl Exp $ + * $PostgreSQL: pgsql/src/backend/utils/adt/ri_triggers.c,v 1.93 2007/03/25 19:45:14 tgl Exp $ * * ---------- */ @@ -277,11 +277,11 @@ RI_FKey_check(PG_FUNCTION_ARGS) * We should not even consider checking the row if it is no longer valid, * since it was either deleted (so the deferred check should be skipped) * or updated (in which case only the latest version of the row should be - * checked). Test its liveness with HeapTupleSatisfiesItself. + * checked). Test its liveness according to SnapshotSelf. * * NOTE: The normal coding rule is that one must acquire the buffer - * content lock to call HeapTupleSatisfiesFOO. We can skip that here - * because we know that AfterTriggerExecute just fetched the tuple + * content lock to call HeapTupleSatisfiesVisibility. We can skip that + * here because we know that AfterTriggerExecute just fetched the tuple * successfully, so there cannot be a VACUUM compaction in progress on the * page (either heap_fetch would have waited for the VACUUM, or the * VACUUM's LockBufferForCleanup would be waiting for us to drop pin). @@ -289,7 +289,7 @@ RI_FKey_check(PG_FUNCTION_ARGS) * can be entitled to change its xmin/xmax. */ Assert(new_row_buf != InvalidBuffer); - if (!HeapTupleSatisfiesItself(new_row->t_data, new_row_buf)) + if (!HeapTupleSatisfiesVisibility(new_row, SnapshotSelf, new_row_buf)) return PointerGetDatum(NULL); /* diff --git a/src/backend/utils/time/tqual.c b/src/backend/utils/time/tqual.c index 13cc211b5db..429005a843a 100644 --- a/src/backend/utils/time/tqual.c +++ b/src/backend/utils/time/tqual.c @@ -1,15 +1,14 @@ /*------------------------------------------------------------------------- * * tqual.c - * POSTGRES "time" qualification code, ie, tuple visibility rules. - * - * The caller must hold at least a shared buffer context lock on the buffer - * containing the tuple. (VACUUM FULL assumes it's sufficient to have - * exclusive lock on the containing relation, instead.) + * POSTGRES "time qualification" code, ie, tuple visibility rules. * * NOTE: all the HeapTupleSatisfies routines will update the tuple's * "hint" status bits if we see that the inserting or deleting transaction - * has now committed or aborted. + * has now committed or aborted. If the hint bits are changed, + * SetBufferCommitInfoNeedsSave is called on the passed-in buffer. + * The caller must hold at least a shared buffer context lock on the buffer + * containing the tuple. * * NOTE: must check TransactionIdIsInProgress (which looks in PGPROC array) * before TransactionIdDidCommit/TransactionIdDidAbort (which look in @@ -32,7 +31,7 @@ * Portions Copyright (c) 1994, Regents of the University of California * * IDENTIFICATION - * $PostgreSQL: pgsql/src/backend/utils/time/tqual.c,v 1.101 2007/01/05 22:19:47 momjian Exp $ + * $PostgreSQL: pgsql/src/backend/utils/time/tqual.c,v 1.102 2007/03/25 19:45:14 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -47,16 +46,21 @@ #include "storage/procarray.h" #include "utils/tqual.h" + +/* Static variables representing various special snapshot semantics */ +SnapshotData SnapshotNowData = {HeapTupleSatisfiesNow}; +SnapshotData SnapshotSelfData = {HeapTupleSatisfiesSelf}; +SnapshotData SnapshotAnyData = {HeapTupleSatisfiesAny}; +SnapshotData SnapshotToastData = {HeapTupleSatisfiesToast}; + /* * These SnapshotData structs are static to simplify memory allocation * (see the hack in GetSnapshotData to avoid repeated malloc/free). */ -static SnapshotData SnapshotDirtyData; -static SnapshotData SerializableSnapshotData; -static SnapshotData LatestSnapshotData; +static SnapshotData SerializableSnapshotData = {HeapTupleSatisfiesMVCC}; +static SnapshotData LatestSnapshotData = {HeapTupleSatisfiesMVCC}; /* Externally visible pointers to valid snapshots: */ -Snapshot SnapshotDirty = &SnapshotDirtyData; Snapshot SerializableSnapshot = NULL; Snapshot LatestSnapshot = NULL; @@ -73,11 +77,11 @@ TransactionId RecentXmin = InvalidTransactionId; TransactionId RecentGlobalXmin = InvalidTransactionId; /* local functions */ -static bool XidInSnapshot(TransactionId xid, Snapshot snapshot); +static bool XidInMVCCSnapshot(TransactionId xid, Snapshot snapshot); /* - * HeapTupleSatisfiesItself + * HeapTupleSatisfiesSelf * True iff heap tuple is valid "for itself". * * Here, we consider the effects of: @@ -101,7 +105,7 @@ static bool XidInSnapshot(TransactionId xid, Snapshot snapshot); * Xmax is not committed))) that has not been committed */ bool -HeapTupleSatisfiesItself(HeapTupleHeader tuple, Buffer buffer) +HeapTupleSatisfiesSelf(HeapTupleHeader tuple, Snapshot snapshot, Buffer buffer) { if (!(tuple->t_infomask & HEAP_XMIN_COMMITTED)) { @@ -278,7 +282,7 @@ HeapTupleSatisfiesItself(HeapTupleHeader tuple, Buffer buffer) * that do catalog accesses. this is unfortunate, but not critical. */ bool -HeapTupleSatisfiesNow(HeapTupleHeader tuple, Buffer buffer) +HeapTupleSatisfiesNow(HeapTupleHeader tuple, Snapshot snapshot, Buffer buffer) { if (!(tuple->t_infomask & HEAP_XMIN_COMMITTED)) { @@ -423,6 +427,16 @@ HeapTupleSatisfiesNow(HeapTupleHeader tuple, Buffer buffer) } /* + * HeapTupleSatisfiesAny + * Dummy "satisfies" routine: any tuple satisfies SnapshotAny. + */ +bool +HeapTupleSatisfiesAny(HeapTupleHeader tuple, Snapshot snapshot, Buffer buffer) +{ + return true; +} + +/* * HeapTupleSatisfiesToast * True iff heap tuple is valid as a TOAST row. * @@ -437,7 +451,8 @@ HeapTupleSatisfiesNow(HeapTupleHeader tuple, Buffer buffer) * table. */ bool -HeapTupleSatisfiesToast(HeapTupleHeader tuple, Buffer buffer) +HeapTupleSatisfiesToast(HeapTupleHeader tuple, Snapshot snapshot, + Buffer buffer) { if (!(tuple->t_infomask & HEAP_XMIN_COMMITTED)) { @@ -676,20 +691,22 @@ HeapTupleSatisfiesUpdate(HeapTupleHeader tuple, CommandId curcid, * previous commands of this transaction * changes made by the current command * - * This is essentially like HeapTupleSatisfiesItself as far as effects of + * This is essentially like HeapTupleSatisfiesSelf as far as effects of * the current transaction and committed/aborted xacts are concerned. * However, we also include the effects of other xacts still in progress. * - * Returns extra information in the global variable SnapshotDirty, namely - * xids of concurrent xacts that affected the tuple. SnapshotDirty->xmin - * is set to InvalidTransactionId if xmin is either committed good or - * committed dead; or to xmin if that transaction is still in progress. - * Similarly for SnapshotDirty->xmax. + * A special hack is that the passed-in snapshot struct is used as an + * output argument to return the xids of concurrent xacts that affected the + * tuple. snapshot->xmin is set to the tuple's xmin if that is another + * transaction that's still in progress; or to InvalidTransactionId if the + * tuple's xmin is committed good, committed dead, or my own xact. Similarly + * for snapshot->xmax and the tuple's xmax. */ bool -HeapTupleSatisfiesDirty(HeapTupleHeader tuple, Buffer buffer) +HeapTupleSatisfiesDirty(HeapTupleHeader tuple, Snapshot snapshot, + Buffer buffer) { - SnapshotDirty->xmin = SnapshotDirty->xmax = InvalidTransactionId; + snapshot->xmin = snapshot->xmax = InvalidTransactionId; if (!(tuple->t_infomask & HEAP_XMIN_COMMITTED)) { @@ -759,7 +776,7 @@ HeapTupleSatisfiesDirty(HeapTupleHeader tuple, Buffer buffer) } else if (TransactionIdIsInProgress(HeapTupleHeaderGetXmin(tuple))) { - SnapshotDirty->xmin = HeapTupleHeaderGetXmin(tuple); + snapshot->xmin = HeapTupleHeaderGetXmin(tuple); /* XXX shouldn't we fall through to look at xmax? */ return true; /* in insertion by other */ } @@ -805,7 +822,7 @@ HeapTupleSatisfiesDirty(HeapTupleHeader tuple, Buffer buffer) if (TransactionIdIsInProgress(HeapTupleHeaderGetXmax(tuple))) { - SnapshotDirty->xmax = HeapTupleHeaderGetXmax(tuple); + snapshot->xmax = HeapTupleHeaderGetXmax(tuple); return true; } @@ -832,8 +849,8 @@ HeapTupleSatisfiesDirty(HeapTupleHeader tuple, Buffer buffer) } /* - * HeapTupleSatisfiesSnapshot - * True iff heap tuple is valid for the given snapshot. + * HeapTupleSatisfiesMVCC + * True iff heap tuple is valid for the given MVCC snapshot. * * Here, we consider the effects of: * all transactions committed as of the time of the given snapshot @@ -853,8 +870,8 @@ HeapTupleSatisfiesDirty(HeapTupleHeader tuple, Buffer buffer) * can't see it.) */ bool -HeapTupleSatisfiesSnapshot(HeapTupleHeader tuple, Snapshot snapshot, - Buffer buffer) +HeapTupleSatisfiesMVCC(HeapTupleHeader tuple, Snapshot snapshot, + Buffer buffer) { if (!(tuple->t_infomask & HEAP_XMIN_COMMITTED)) { @@ -949,7 +966,7 @@ HeapTupleSatisfiesSnapshot(HeapTupleHeader tuple, Snapshot snapshot, * By here, the inserting transaction has committed - have to check * when... */ - if (XidInSnapshot(HeapTupleHeaderGetXmin(tuple), snapshot)) + if (XidInMVCCSnapshot(HeapTupleHeaderGetXmin(tuple), snapshot)) return false; /* treat as still in progress */ if (tuple->t_infomask & HEAP_XMAX_INVALID) /* xid invalid or aborted */ @@ -994,7 +1011,7 @@ HeapTupleSatisfiesSnapshot(HeapTupleHeader tuple, Snapshot snapshot, /* * OK, the deleting transaction committed too ... but when? */ - if (XidInSnapshot(HeapTupleHeaderGetXmax(tuple), snapshot)) + if (XidInMVCCSnapshot(HeapTupleHeaderGetXmax(tuple), snapshot)) return true; /* treat as still in progress */ return false; @@ -1241,8 +1258,6 @@ GetLatestSnapshot(void) * Copy the given snapshot. * * The copy is palloc'd in the current memory context. - * - * Note that this will not work on "special" snapshots. */ Snapshot CopySnapshot(Snapshot snapshot) @@ -1290,7 +1305,7 @@ CopySnapshot(Snapshot snapshot) * This is currently identical to pfree, but is provided for cleanliness. * * Do *not* apply this to the results of GetTransactionSnapshot or - * GetLatestSnapshot. + * GetLatestSnapshot, since those are just static structs. */ void FreeSnapshot(Snapshot snapshot) @@ -1316,7 +1331,7 @@ FreeXactSnapshot(void) } /* - * XidInSnapshot + * XidInMVCCSnapshot * Is the given XID still-in-progress according to the snapshot? * * Note: GetSnapshotData never stores either top xid or subxids of our own @@ -1325,7 +1340,7 @@ FreeXactSnapshot(void) * apply this for known-committed XIDs. */ static bool -XidInSnapshot(TransactionId xid, Snapshot snapshot) +XidInMVCCSnapshot(TransactionId xid, Snapshot snapshot) { uint32 i; |