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Mega-commit to make heap_open/heap_openr/heap_close take an

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additional argument specifying the kind of lock to acquire/release (or
'NoLock' to do no lock processing).  Ensure that all relations are locked
with some appropriate lock level before being examined --- this ensures
that relevant shared-inval messages have been processed and should prevent
problems caused by concurrent VACUUM.  Fix several bugs having to do with
mismatched increment/decrement of relation ref count and mismatched
heap_open/close (which amounts to the same thing).  A bogus ref count on
a relation doesn't matter much *unless* a SI Inval message happens to
arrive at the wrong time, which is probably why we got away with this
sloppiness for so long.  Repair missing grab of AccessExclusiveLock in
DROP TABLE, ALTER/RENAME TABLE, etc, as noted by Hiroshi.
Recommend 'make clean all' after pulling this update; I modified the
Relation struct layout slightly.
Will post further discussion to pghackers list shortly.
This commit is contained in:
Tom Lane
1999-09-18 19:08:25 +00:00
parent 6c86fd5ba4
commit bd272cace6
70 changed files with 1094 additions and 1215 deletions
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60
src/backend/executor/execAmi.c
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@ -1,11 +1,11 @@
/*-------------------------------------------------------------------------
*
* execAmi.c
* miscellanious executor access method routines
* miscellaneous executor access method routines
*
* Copyright (c) 1994, Regents of the University of California
*
* $Id: execAmi.c,v 1.41 1999/07/17 20:16:56 momjian Exp $
* $Id: execAmi.c,v 1.42 1999/09/18 19:06:47 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@ -52,7 +52,6 @@
static Pointer ExecBeginScan(Relation relation, int nkeys, ScanKey skeys,
bool isindex, ScanDirection dir, Snapshot snapshot);
static Relation ExecOpenR(Oid relationOid, bool isindex);
/* ----------------------------------------------------------------
* ExecOpenScanR
@ -90,7 +89,22 @@ ExecOpenScanR(Oid relOid,
* abstraction someday -cim 9/9/89
* ----------------
*/
relation = ExecOpenR(relOid, isindex);
/* ----------------
* open the relation with the correct call depending
* on whether this is a heap relation or an index relation.
*
* Do not lock the rel here; beginscan will acquire AccessShareLock.
* ----------------
*/
if (isindex)
relation = index_open(relOid);
else
relation = heap_open(relOid, NoLock);
if (relation == NULL)
elog(ERROR, "ExecOpenScanR: failed to open relation %u", relOid);
scanDesc = ExecBeginScan(relation,
nkeys,
skeys,
@ -104,35 +118,6 @@ ExecOpenScanR(Oid relOid,
*returnScanDesc = scanDesc;
}
/* ----------------------------------------------------------------
* ExecOpenR
*
* returns a relation descriptor given an object id.
* ----------------------------------------------------------------
*/
static Relation
ExecOpenR(Oid relationOid, bool isindex)
{
Relation relation;
relation = (Relation) NULL;
/* ----------------
* open the relation with the correct call depending
* on whether this is a heap relation or an index relation.
* ----------------
*/
if (isindex)
relation = index_open(relationOid);
else
relation = heap_open(relationOid);
if (relation == NULL)
elog(DEBUG, "ExecOpenR: relation == NULL, heap_open failed.");
return relation;
}
/* ----------------------------------------------------------------
* ExecBeginScan
*
@ -243,15 +228,20 @@ ExecCloseR(Plan *node)
if (scanDesc != NULL)
heap_endscan(scanDesc);
/*
* endscan released AccessShareLock acquired by beginscan. If we are
* holding any stronger locks on the rel, they should be held till end of
* xact. Therefore, we need only close the rel and not release locks.
*/
if (relation != NULL)
heap_close(relation);
heap_close(relation, NoLock);
/* ----------------
* if this is an index scan then we have to take care
* of the index relations as well..
* ----------------
*/
if (nodeTag(node) == T_IndexScan)
if (IsA(node, IndexScan))
{
IndexScan *iscan = (IndexScan *) node;
IndexScanState *indexstate;