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, 21 insertions, 18 deletions

diff --git a/src/backend/commands/trigger.c b/src/backend/commands/trigger.c
index 33340291e1c..22dfcac0524 100644
--- a/src/backend/commands/trigger.c
+++ b/src/backend/commands/trigger.c
@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/commands/trigger.c,v 1.79 2000/11/08 22:09:57 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/commands/trigger.c,v 1.80 2000/11/16 22:30:18 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -154,11 +154,11 @@ CreateTrigger(CreateTrigStmt *stmt)
 	 * Find and validate the trigger function.
 	 */
 	MemSet(fargtypes, 0, FUNC_MAX_ARGS * sizeof(Oid));
-	tuple = SearchSysCacheTuple(PROCNAME,
-								PointerGetDatum(stmt->funcname),
-								Int32GetDatum(0),
-								PointerGetDatum(fargtypes),
-								0);
+	tuple = SearchSysCache(PROCNAME,
+						   PointerGetDatum(stmt->funcname),
+						   Int32GetDatum(0),
+						   PointerGetDatum(fargtypes),
+						   0);
 	if (!HeapTupleIsValid(tuple))
 		elog(ERROR, "CreateTrigger: function %s() does not exist",
 			 stmt->funcname);
@@ -167,6 +167,8 @@ CreateTrigger(CreateTrigStmt *stmt)
 			 stmt->funcname);
 	funcoid = tuple->t_data->t_oid;
 	funclang = ((Form_pg_proc) GETSTRUCT(tuple))->prolang;
+	ReleaseSysCache(tuple);
+
 	if (funclang != ClanguageId &&
 		funclang != NEWClanguageId &&
 		funclang != INTERNALlanguageId &&
@@ -174,14 +176,15 @@ CreateTrigger(CreateTrigStmt *stmt)
 	{
 		HeapTuple	langTup;
 
-		langTup = SearchSysCacheTuple(LANGOID,
-									  ObjectIdGetDatum(funclang),
-									  0, 0, 0);
+		langTup = SearchSysCache(LANGOID,
+								 ObjectIdGetDatum(funclang),
+								 0, 0, 0);
 		if (!HeapTupleIsValid(langTup))
 			elog(ERROR, "CreateTrigger: cache lookup for PL %u failed",
 				 funclang);
 		if (((Form_pg_language) GETSTRUCT(langTup))->lanispl == false)
 			elog(ERROR, "CreateTrigger: only builtin, C and PL functions are supported");
+		ReleaseSysCache(langTup);
 	}
 
 	/*
@@ -268,9 +271,9 @@ CreateTrigger(CreateTrigStmt *stmt)
 	 * rebuild relcache entries.
 	 */
 	pgrel = heap_openr(RelationRelationName, RowExclusiveLock);
-	tuple = SearchSysCacheTupleCopy(RELNAME,
-									PointerGetDatum(stmt->relname),
-									0, 0, 0);
+	tuple = SearchSysCacheCopy(RELNAME,
+							   PointerGetDatum(stmt->relname),
+							   0, 0, 0);
 	if (!HeapTupleIsValid(tuple))
 		elog(ERROR, "CreateTrigger: relation %s not found in pg_class",
 			 stmt->relname);
@@ -353,9 +356,9 @@ DropTrigger(DropTrigStmt *stmt)
 	 * rebuild relcache entries.
 	 */
 	pgrel = heap_openr(RelationRelationName, RowExclusiveLock);
-	tuple = SearchSysCacheTupleCopy(RELNAME,
-									PointerGetDatum(stmt->relname),
-									0, 0, 0);
+	tuple = SearchSysCacheCopy(RELNAME,
+							   PointerGetDatum(stmt->relname),
+							   0, 0, 0);
 	if (!HeapTupleIsValid(tuple))
 		elog(ERROR, "DropTrigger: relation %s not found in pg_class",
 			 stmt->relname);
@@ -426,9 +429,9 @@ RelationRemoveTriggers(Relation rel)
 		Relation	ridescs[Num_pg_class_indices];
 
 		pgrel = heap_openr(RelationRelationName, RowExclusiveLock);
-		tup = SearchSysCacheTupleCopy(RELOID,
-									  RelationGetRelid(rel),
-									  0, 0, 0);
+		tup = SearchSysCacheCopy(RELOID,
+								 RelationGetRelid(rel),
+								 0, 0, 0);
 		if (!HeapTupleIsValid(tup))
 			elog(ERROR, "RelationRemoveTriggers: relation %u not found in pg_class",
 				 RelationGetRelid(rel));