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, 32 insertions, 22 deletions

diff --git a/src/pl/plperl/plperl.c b/src/pl/plperl/plperl.c
index c1516ea6928..81a4cd75d4b 100644
--- a/src/pl/plperl/plperl.c
+++ b/src/pl/plperl/plperl.c
@@ -33,7 +33,7 @@
  *	  ENHANCEMENTS, OR MODIFICATIONS.
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/pl/plperl/plperl.c,v 1.14 2000/10/24 17:01:05 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/pl/plperl/plperl.c,v 1.15 2000/11/16 22:30:49 tgl Exp $
  *
  **********************************************************************/
 
@@ -521,9 +521,9 @@ plperl_func_handler(PG_FUNCTION_ARGS)
 		/************************************************************
 		 * Lookup the pg_proc tuple by Oid
 		 ************************************************************/
-		procTup = SearchSysCacheTuple(PROCOID,
-									  ObjectIdGetDatum(fcinfo->flinfo->fn_oid),
-									  0, 0, 0);
+		procTup = SearchSysCache(PROCOID,
+								 ObjectIdGetDatum(fcinfo->flinfo->fn_oid),
+								 0, 0, 0);
 		if (!HeapTupleIsValid(procTup))
 		{
 			free(prodesc->proname);
@@ -537,9 +537,9 @@ plperl_func_handler(PG_FUNCTION_ARGS)
 		 * Get the required information for input conversion of the
 		 * return value.
 		 ************************************************************/
-		typeTup = SearchSysCacheTuple(TYPEOID,
-								ObjectIdGetDatum(procStruct->prorettype),
-									  0, 0, 0);
+		typeTup = SearchSysCache(TYPEOID,
+								 ObjectIdGetDatum(procStruct->prorettype),
+								 0, 0, 0);
 		if (!HeapTupleIsValid(typeTup))
 		{
 			free(prodesc->proname);
@@ -560,6 +560,8 @@ plperl_func_handler(PG_FUNCTION_ARGS)
 		prodesc->result_in_elem = (Oid) (typeStruct->typelem);
 		prodesc->result_in_len = typeStruct->typlen;
 
+		ReleaseSysCache(typeTup);
+
 		/************************************************************
 		 * Get the required information for output conversion
 		 * of all procedure arguments
@@ -567,9 +569,9 @@ plperl_func_handler(PG_FUNCTION_ARGS)
 		prodesc->nargs = procStruct->pronargs;
 		for (i = 0; i < prodesc->nargs; i++)
 		{
-			typeTup = SearchSysCacheTuple(TYPEOID,
+			typeTup = SearchSysCache(TYPEOID,
 							ObjectIdGetDatum(procStruct->proargtypes[i]),
-										  0, 0, 0);
+									 0, 0, 0);
 			if (!HeapTupleIsValid(typeTup))
 			{
 				free(prodesc->proname);
@@ -587,7 +589,7 @@ plperl_func_handler(PG_FUNCTION_ARGS)
 			fmgr_info(typeStruct->typoutput, &(prodesc->arg_out_func[i]));
 			prodesc->arg_out_elem[i] = (Oid) (typeStruct->typelem);
 			prodesc->arg_out_len[i] = typeStruct->typlen;
-
+			ReleaseSysCache(typeTup);
 		}
 
 		/************************************************************
@@ -617,6 +619,8 @@ plperl_func_handler(PG_FUNCTION_ARGS)
 		 ************************************************************/
 		hv_store(plperl_proc_hash, internal_proname, proname_len,
 				 newSViv((IV) prodesc), 0);
+
+		ReleaseSysCache(procTup);
 	}
 	else
 	{
@@ -744,9 +748,9 @@ plperl_trigger_handler(PG_FUNCTION_ARGS)
 		/************************************************************
 		 * Lookup the pg_proc tuple by Oid
 		 ************************************************************/
-		procTup = SearchSysCacheTuple(PROCOID,
-									  ObjectIdGetDatum(fcinfo->flinfo->fn_oid),
-									  0, 0, 0);
+		procTup = SearchSysCache(PROCOID,
+								 ObjectIdGetDatum(fcinfo->flinfo->fn_oid),
+								 0, 0, 0);
 		if (!HeapTupleIsValid(procTup))
 		{
 			free(prodesc->proname);
@@ -819,6 +823,8 @@ plperl_trigger_handler(PG_FUNCTION_ARGS)
 		hashent = Tcl_CreateHashEntry(plperl_proc_hash,
 									  prodesc->proname, &hashnew);
 		Tcl_SetHashValue(hashent, (ClientData) prodesc);
+
+		ReleaseSysCache(procTup);
 	}
 	else
 	{
@@ -1068,9 +1074,9 @@ plperl_trigger_handler(PG_FUNCTION_ARGS)
 		 * Lookup the attribute type in the syscache
 		 * for the input function
 		 ************************************************************/
-		typeTup = SearchSysCacheTuple(TYPEOID,
+		typeTup = SearchSysCache(TYPEOID,
 				  ObjectIdGetDatum(tupdesc->attrs[attnum - 1]->atttypid),
-									  0, 0, 0);
+								 0, 0, 0);
 		if (!HeapTupleIsValid(typeTup))
 		{
 			elog(ERROR, "plperl: Cache lookup for attribute '%s' type %u failed",
@@ -1079,6 +1085,7 @@ plperl_trigger_handler(PG_FUNCTION_ARGS)
 		}
 		typinput = (Oid) (((Form_pg_type) GETSTRUCT(typeTup))->typinput);
 		typelem = (Oid) (((Form_pg_type) GETSTRUCT(typeTup))->typelem);
+		ReleaseSysCache(typeTup);
 
 		/************************************************************
 		 * Set the attribute to NOT NULL and convert the contents
@@ -1538,9 +1545,9 @@ plperl_SPI_prepare(ClientData cdata, Tcl_Interp *interp,
 	 ************************************************************/
 	for (i = 0; i < nargs; i++)
 	{
-		typeTup = SearchSysCacheTuple(TYPNAME,
-									  PointerGetDatum(args[i]),
-									  0, 0, 0);
+		typeTup = SearchSysCache(TYPNAME,
+								 PointerGetDatum(args[i]),
+								 0, 0, 0);
 		if (!HeapTupleIsValid(typeTup))
 			elog(ERROR, "plperl: Cache lookup of type %s failed", args[i]);
 		qdesc->argtypes[i] = typeTup->t_data->t_oid;
@@ -1549,6 +1556,7 @@ plperl_SPI_prepare(ClientData cdata, Tcl_Interp *interp,
 		qdesc->argtypelems[i] = ((Form_pg_type) GETSTRUCT(typeTup))->typelem;
 		qdesc->argvalues[i] = (Datum) NULL;
 		qdesc->arglen[i] = (int) (((Form_pg_type) GETSTRUCT(typeTup))->typlen);
+		ReleaseSysCache(typeTup);
 	}
 
 	/************************************************************
@@ -2084,9 +2092,9 @@ plperl_set_tuple_values(Tcl_Interp *interp, char *arrayname,
 		 * Lookup the attribute type in the syscache
 		 * for the output function
 		 ************************************************************/
-		typeTup = SearchSysCacheTuple(TYPEOID,
+		typeTup = SearchSysCache(TYPEOID,
 						   ObjectIdGetDatum(tupdesc->attrs[i]->atttypid),
-									  0, 0, 0);
+								 0, 0, 0);
 		if (!HeapTupleIsValid(typeTup))
 		{
 			elog(ERROR, "plperl: Cache lookup for attribute '%s' type %u failed",
@@ -2095,6 +2103,7 @@ plperl_set_tuple_values(Tcl_Interp *interp, char *arrayname,
 
 		typoutput = (Oid) (((Form_pg_type) GETSTRUCT(typeTup))->typoutput);
 		typelem = (Oid) (((Form_pg_type) GETSTRUCT(typeTup))->typelem);
+		ReleaseSysCache(typeTup);
 
 		/************************************************************
 		 * If there is a value, set the variable
@@ -2156,9 +2165,9 @@ plperl_build_tuple_argument(HeapTuple tuple, TupleDesc tupdesc)
 		 * Lookup the attribute type in the syscache
 		 * for the output function
 		 ************************************************************/
-		typeTup = SearchSysCacheTuple(TYPEOID,
+		typeTup = SearchSysCache(TYPEOID,
 						   ObjectIdGetDatum(tupdesc->attrs[i]->atttypid),
-									  0, 0, 0);
+								 0, 0, 0);
 		if (!HeapTupleIsValid(typeTup))
 		{
 			elog(ERROR, "plperl: Cache lookup for attribute '%s' type %u failed",
@@ -2167,6 +2176,7 @@ plperl_build_tuple_argument(HeapTuple tuple, TupleDesc tupdesc)
 
 		typoutput = (Oid) (((Form_pg_type) GETSTRUCT(typeTup))->typoutput);
 		typelem = (Oid) (((Form_pg_type) GETSTRUCT(typeTup))->typelem);
+		ReleaseSysCache(typeTup);
 
 		/************************************************************
 		 * If there is a value, append the attribute name and the