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

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.

src/backend/parser/analyze.c

@@ -5,7 +5,7 @@
  *
  * Copyright (c) 1994, Regents of the University of California
  *
- *	$Id: analyze.c,v 1.118 1999/08/21 03:48:55 tgl Exp $
+ *	$Id: analyze.c,v 1.119 1999/09/18 19:07:12 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -64,7 +64,7 @@ parse_analyze(List *pl, ParseState *parentParseState)
 
 		parsetree = transformStmt(pstate, lfirst(pl));
 		if (pstate->p_target_relation != NULL)
-			heap_close(pstate->p_target_relation);
+			heap_close(pstate->p_target_relation, AccessShareLock);
 		pstate->p_target_relation = NULL;
 		pstate->p_target_rangetblentry = NULL;
 
@@ -73,7 +73,7 @@ parse_analyze(List *pl, ParseState *parentParseState)
 			result = lappend(result,
 							 transformStmt(pstate, lfirst(extras_before)));
 			if (pstate->p_target_relation != NULL)
-				heap_close(pstate->p_target_relation);
+				heap_close(pstate->p_target_relation, AccessShareLock);
 			pstate->p_target_relation = NULL;
 			pstate->p_target_rangetblentry = NULL;
 			extras_before = lnext(extras_before);
@@ -86,7 +86,7 @@ parse_analyze(List *pl, ParseState *parentParseState)
 			result = lappend(result,
 							 transformStmt(pstate, lfirst(extras_after)));
 			if (pstate->p_target_relation != NULL)
-				heap_close(pstate->p_target_relation);
+				heap_close(pstate->p_target_relation, AccessShareLock);
 			pstate->p_target_relation = NULL;
 			pstate->p_target_rangetblentry = NULL;
 			extras_after = lnext(extras_after);

src/backend/parser/parse_clause.c

@@ -7,7 +7,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/parser/parse_clause.c,v 1.44 1999/08/21 03:48:55 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/parser/parse_clause.c,v 1.45 1999/09/18 19:07:12 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -75,11 +75,11 @@ setTargetTable(ParseState *pstate, char *relname)
 
 	/* This could only happen for multi-action rules */
 	if (pstate->p_target_relation != NULL)
-		heap_close(pstate->p_target_relation);
+		heap_close(pstate->p_target_relation, AccessShareLock);
 
 	pstate->p_target_rangetblentry = rte;
-	pstate->p_target_relation = heap_open(rte->relid);
-	/* will close relation later */
+	pstate->p_target_relation = heap_open(rte->relid, AccessShareLock);
+	/* will close relation later, see analyze.c */
 }
 
 /*

src/backend/parser/parse_func.c

@@ -7,7 +7,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/parser/parse_func.c,v 1.54 1999/08/22 20:15:03 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/parser/parse_func.c,v 1.55 1999/09/18 19:07:12 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -139,7 +139,7 @@ agg_get_candidates(char *aggname,
 	fmgr_info(F_NAMEEQ, (FmgrInfo *) &aggKey[0].sk_func);
 	aggKey[0].sk_argument = NameGetDatum(aggname);
 
-	pg_aggregate_desc = heap_openr(AggregateRelationName);
+	pg_aggregate_desc = heap_openr(AggregateRelationName, AccessShareLock);
 	pg_aggregate_scan = heap_beginscan(pg_aggregate_desc,
 									   0,
 									   SnapshotSelf,	/* ??? */
@@ -159,7 +159,7 @@ agg_get_candidates(char *aggname,
 	}
 
 	heap_endscan(pg_aggregate_scan);
-	heap_close(pg_aggregate_desc);
+	heap_close(pg_aggregate_desc, AccessShareLock);
 
 	return ncandidates;
 }	/* agg_get_candidates() */
@@ -310,11 +310,11 @@ ParseFuncOrColumn(ParseState *pstate, char *funcname, List *fargs,
 			if (attisset)
 			{
 				toid = exprType(first_arg);
-				rd = heap_openr(typeidTypeName(toid));
+				rd = heap_openr(typeidTypeName(toid), NoLock);
 				if (RelationIsValid(rd))
 				{
 					relname = RelationGetRelationName(rd)->data;
-					heap_close(rd);
+					heap_close(rd, NoLock);
 				}
 				else
 					elog(ERROR, "Type '%s' is not a relation type",
@@ -646,7 +646,7 @@ func_get_candidates(char *funcname, int nargs)
 	CandidateList current_candidate;
 	int			i;
 
-	heapRelation = heap_openr(ProcedureRelationName);
+	heapRelation = heap_openr(ProcedureRelationName, AccessShareLock);
 	ScanKeyEntryInitialize(&skey,
 						   (bits16) 0x0,
 						   (AttrNumber) 1,
@@ -690,7 +690,7 @@ func_get_candidates(char *funcname, int nargs)
 
 	index_endscan(sd);
 	index_close(idesc);
-	heap_close(heapRelation);
+	heap_close(heapRelation, AccessShareLock);
 
 	return candidates;
 }
@@ -1086,7 +1086,7 @@ find_inheritors(Oid relid, Oid **supervec)
 	visited = DLNewList();
 
 
-	inhrel = heap_openr(InheritsRelationName);
+	inhrel = heap_openr(InheritsRelationName, AccessShareLock);
 	inhtupdesc = RelationGetDescr(inhrel);
 
 	/*
@@ -1140,12 +1140,12 @@ find_inheritors(Oid relid, Oid **supervec)
 
 		if (qentry != (SuperQE *) NULL)
 		{
-
 			/* save the type id, rather than the relation id */
-			if ((rd = heap_open(qentry->sqe_relid)) == (Relation) NULL)
+			rd = heap_open(qentry->sqe_relid, NoLock);
+			if (! RelationIsValid(rd))
 				elog(ERROR, "Relid %u does not exist", qentry->sqe_relid);
 			qentry->sqe_relid = typeTypeId(typenameType(RelationGetRelationName(rd)->data));
-			heap_close(rd);
+			heap_close(rd, NoLock);
 
 			DLAddTail(visited, qe);
 
@@ -1153,7 +1153,7 @@ find_inheritors(Oid relid, Oid **supervec)
 		}
 	} while (qentry != (SuperQE *) NULL);
 
-	heap_close(inhrel);
+	heap_close(inhrel, AccessShareLock);
 
 	if (nvisited > 0)
 	{
@@ -1370,16 +1370,13 @@ ParseComplexProjection(ParseState *pstate,
 					 */
 
 					/* add a tlist to the func node and return the Iter */
-					rd = heap_openr(typeidTypeName(argtype));
+					rd = heap_openr(typeidTypeName(argtype), NoLock);
 					if (RelationIsValid(rd))
 					{
 						relid = RelationGetRelid(rd);
-						heap_close(rd);
-					}
-					if (RelationIsValid(rd))
-					{
 						func->func_tlist = setup_tlist(funcname, argrelid);
 						iter->itertype = attnumTypeId(rd, attnum);
+						heap_close(rd, NoLock);
 						return (Node *) iter;
 					}
 					else
@@ -1427,16 +1424,12 @@ ParseComplexProjection(ParseState *pstate,
 				{
 
 					/* add a tlist to the func node */
-					rd = heap_openr(typeidTypeName(argtype));
-					if (RelationIsValid(rd))
-					{
-						relid = RelationGetRelid(rd);
-						heap_close(rd);
-					}
+					rd = heap_openr(typeidTypeName(argtype), NoLock);
 					if (RelationIsValid(rd))
 					{
 						Expr	   *newexpr;
 
+						relid = RelationGetRelid(rd);
 						funcnode->func_tlist = setup_tlist(funcname, argrelid);
 						funcnode->functype = attnumTypeId(rd, attnum);
 
@@ -1446,8 +1439,11 @@ ParseComplexProjection(ParseState *pstate,
 						newexpr->oper = (Node *) funcnode;
 						newexpr->args = expr->args;
 
+						heap_close(rd, NoLock);
+
 						return (Node *) newexpr;
 					}
+					/* XXX why not an error condition if it's not there? */
 
 				}
 
@@ -1461,18 +1457,19 @@ ParseComplexProjection(ParseState *pstate,
 				 * If the Param is a complex type, this could be a
 				 * projection
 				 */
-				rd = heap_openr(typeidTypeName(param->paramtype));
+				rd = heap_openr(typeidTypeName(param->paramtype), NoLock);
 				if (RelationIsValid(rd))
 				{
 					relid = RelationGetRelid(rd);
-					heap_close(rd);
 					if ((attnum = get_attnum(relid, funcname))
 						!= InvalidAttrNumber)
 					{
 						param->paramtype = attnumTypeId(rd, attnum);
 						param->param_tlist = setup_tlist(funcname, relid);
+						heap_close(rd, NoLock);
 						return (Node *) param;
 					}
+					heap_close(rd, NoLock);
 				}
 				break;
 			}

src/backend/parser/parse_oper.c

@@ -7,7 +7,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/parser/parse_oper.c,v 1.31 1999/08/26 04:59:15 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/parser/parse_oper.c,v 1.32 1999/09/18 19:07:12 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -75,7 +75,6 @@ binary_oper_get_candidates(char *opname,
 	HeapScanDesc pg_operator_scan;
 	HeapTuple	tup;
 	Form_pg_operator oper;
-	int			nkeys;
 	int			ncandidates = 0;
 	ScanKeyData opKey[3];
 
@@ -91,13 +90,11 @@ binary_oper_get_candidates(char *opname,
 						   F_CHAREQ,
 						   CharGetDatum('b'));
 
-	nkeys = 2;
-
-	pg_operator_desc = heap_openr(OperatorRelationName);
+	pg_operator_desc = heap_openr(OperatorRelationName, AccessShareLock);
 	pg_operator_scan = heap_beginscan(pg_operator_desc,
 									  0,
 									  SnapshotSelf,		/* ??? */
-									  nkeys,
+									  2,
 									  opKey);
 
 	while (HeapTupleIsValid(tup = heap_getnext(pg_operator_scan, 0)))
@@ -114,7 +111,7 @@ binary_oper_get_candidates(char *opname,
 	}
 
 	heap_endscan(pg_operator_scan);
-	heap_close(pg_operator_desc);
+	heap_close(pg_operator_desc, AccessShareLock);
 
 	return ncandidates;
 }	/* binary_oper_get_candidates() */
@@ -522,7 +519,7 @@ unary_oper_get_candidates(char *op,
 	fmgr_info(F_CHAREQ, (FmgrInfo *) &opKey[1].sk_func);
 	opKey[1].sk_argument = CharGetDatum(rightleft);
 
-	pg_operator_desc = heap_openr(OperatorRelationName);
+	pg_operator_desc = heap_openr(OperatorRelationName, AccessShareLock);
 	pg_operator_scan = heap_beginscan(pg_operator_desc,
 									  0,
 									  SnapshotSelf,		/* ??? */
@@ -545,7 +542,7 @@ unary_oper_get_candidates(char *op,
 	}
 
 	heap_endscan(pg_operator_scan);
-	heap_close(pg_operator_desc);
+	heap_close(pg_operator_desc, AccessShareLock);
 
 	return ncandidates;
 }	/* unary_oper_get_candidates() */

src/backend/parser/parse_relation.c

@@ -7,7 +7,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/parser/parse_relation.c,v 1.26 1999/07/19 00:26:20 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/parser/parse_relation.c,v 1.27 1999/09/18 19:07:12 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -202,14 +202,9 @@ addRangeTableEntry(ParseState *pstate,
 	rte->relname = pstrdup(relname);
 	rte->refname = pstrdup(refname);
 
-	relation = heap_openr(relname);
-	if (relation == NULL)
-		elog(ERROR, "%s: %s",
-			 relname, aclcheck_error_strings[ACLCHECK_NO_CLASS]);
-
+	relation = heap_openr(relname, AccessShareLock);
 	rte->relid = RelationGetRelid(relation);
-
-	heap_close(relation);
+	heap_close(relation, AccessShareLock);
 
 	/*
 	 * Flags - zero or more from inheritance,union,version or recursive
@@ -246,10 +241,7 @@ expandAll(ParseState *pstate, char *relname, char *refname, int *this_resno)
 	if (rte == NULL)
 		rte = addRangeTableEntry(pstate, relname, refname, FALSE, FALSE);
 
-	rel = heap_open(rte->relid);
-	if (rel == NULL)
-		elog(ERROR, "Unable to expand all -- heap_open failed on %s",
-			 rte->refname);
+	rel = heap_open(rte->relid, AccessShareLock);
 
 	maxattrs = RelationGetNumberOfAttributes(rel);
 
@@ -278,7 +270,7 @@ expandAll(ParseState *pstate, char *relname, char *refname, int *this_resno)
 		te_list = lappend(te_list, te);
 	}
 
-	heap_close(rel);
+	heap_close(rel, AccessShareLock);
 
 	return te_list;
 }