Change SearchSysCache coding conventions so that a reference count is

maintained for each cache entry.  A cache entry will not be freed until
the matching ReleaseSysCache call has been executed.  This eliminates
worries about cache entries getting dropped while still in use.  See
my posting to pg-hackers of even date for more info.

1 files changed, 33 insertions, 31 deletions

diff --git a/src/backend/parser/parse_func.c b/src/backend/parser/parse_func.c
index ea0544f701e..688c5bfa306 100644
--- a/src/backend/parser/parse_func.c
+++ b/src/backend/parser/parse_func.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/parser/parse_func.c,v 1.93 2000/11/11 19:49:26 thomas Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/parser/parse_func.c,v 1.94 2000/11/16 22:30:28 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -354,19 +354,19 @@ ParseFuncOrColumn(ParseState *pstate, char *funcname, List *fargs,
 		CandidateList candidates;
 
 		/* try for exact match first... */
-		if (SearchSysCacheTuple(AGGNAME,
-								PointerGetDatum(funcname),
-								ObjectIdGetDatum(basetype),
-								0, 0))
+		if (SearchSysCacheExists(AGGNAME,
+								 PointerGetDatum(funcname),
+								 ObjectIdGetDatum(basetype),
+								 0, 0))
 			return (Node *) ParseAgg(pstate, funcname, basetype,
 									 fargs, agg_star, agg_distinct,
 									 precedence);
 
 		/* check for aggregate-that-accepts-any-type (eg, COUNT) */
-		if (SearchSysCacheTuple(AGGNAME,
-								PointerGetDatum(funcname),
-								ObjectIdGetDatum(0),
-								0, 0))
+		if (SearchSysCacheExists(AGGNAME,
+								 PointerGetDatum(funcname),
+								 ObjectIdGetDatum(0),
+								 0, 0))
 			return (Node *) ParseAgg(pstate, funcname, 0,
 									 fargs, agg_star, agg_distinct,
 									 precedence);
@@ -450,7 +450,7 @@ ParseFuncOrColumn(ParseState *pstate, char *funcname, List *fargs,
 			if (rte->relname == NULL)
 				elog(ERROR,
 					 "function applied to tuple is not supported for subSELECTs");
-			toid = typeTypeId(typenameType(rte->relname));
+			toid = typenameTypeId(rte->relname);
 
 			/* replace it in the arg list */
 			lfirst(i) = makeVar(vnum, 0, toid, -1, sublevels_up);
@@ -531,15 +531,14 @@ ParseFuncOrColumn(ParseState *pstate, char *funcname, List *fargs,
 			 */
 			if (nargs == 1)
 			{
-				Type		tp;
+				Oid			targetType;
 
-				tp = SearchSysCacheTuple(TYPENAME,
-										 PointerGetDatum(funcname),
-										 0, 0, 0);
-				if (HeapTupleIsValid(tp))
+				targetType = GetSysCacheOid(TYPENAME,
+											PointerGetDatum(funcname),
+											0, 0, 0);
+				if (OidIsValid(targetType))
 				{
 					Oid			sourceType = oid_array[0];
-					Oid			targetType = typeTypeId(tp);
 					Node	   *arg1 = lfirst(fargs);
 
 					if ((sourceType == UNKNOWNOID && IsA(arg1, Const)) ||
@@ -573,6 +572,7 @@ ParseFuncOrColumn(ParseState *pstate, char *funcname, List *fargs,
 				if (typeTypeFlag(tp) == 'c')
 					elog(ERROR, "No such attribute or function '%s'",
 						 funcname);
+				ReleaseSysCache(tp);
 			}
 
 			/* Else generate a detailed complaint */
@@ -1037,11 +1037,11 @@ func_get_detail(char *funcname,
 	HeapTuple	ftup;
 
 	/* attempt to find with arguments exactly as specified... */
-	ftup = SearchSysCacheTuple(PROCNAME,
-							   PointerGetDatum(funcname),
-							   Int32GetDatum(nargs),
-							   PointerGetDatum(argtypes),
-							   0);
+	ftup = SearchSysCache(PROCNAME,
+						  PointerGetDatum(funcname),
+						  Int32GetDatum(nargs),
+						  PointerGetDatum(argtypes),
+						  0);
 
 	if (HeapTupleIsValid(ftup))
 	{
@@ -1085,11 +1085,11 @@ func_get_detail(char *funcname,
 				if (ncandidates == 1)
 				{
 					*true_typeids = current_function_typeids->args;
-					ftup = SearchSysCacheTuple(PROCNAME,
-											   PointerGetDatum(funcname),
-											   Int32GetDatum(nargs),
+					ftup = SearchSysCache(PROCNAME,
+										  PointerGetDatum(funcname),
+										  Int32GetDatum(nargs),
 										  PointerGetDatum(*true_typeids),
-											   0);
+										  0);
 					Assert(HeapTupleIsValid(ftup));
 					break;
 				}
@@ -1107,12 +1107,13 @@ func_get_detail(char *funcname,
 					if (*true_typeids != NULL)
 					{
 						/* was able to choose a best candidate */
-						ftup = SearchSysCacheTuple(PROCNAME,
-											   PointerGetDatum(funcname),
-												   Int32GetDatum(nargs),
-										  PointerGetDatum(*true_typeids),
-												   0);
+						ftup = SearchSysCache(PROCNAME,
+											  PointerGetDatum(funcname),
+											  Int32GetDatum(nargs),
+											  PointerGetDatum(*true_typeids),
+											  0);
 						Assert(HeapTupleIsValid(ftup));
+						break;
 					}
 
 					/*
@@ -1143,6 +1144,7 @@ func_get_detail(char *funcname,
 		*funcid = ftup->t_data->t_oid;
 		*rettype = pform->prorettype;
 		*retset = pform->proretset;
+		ReleaseSysCache(ftup);
 		return true;
 	}
 	return false;
@@ -1284,7 +1286,7 @@ find_inheritors(Oid relid, Oid **supervec)
 
 			relid = lfirsti(elt);
 			rd = heap_open(relid, NoLock);
-			trelid = typeTypeId(typenameType(RelationGetRelationName(rd)));
+			trelid = typenameTypeId(RelationGetRelationName(rd));
 			heap_close(rd, NoLock);
 			*relidvec++ = trelid;
 		}