From e1107fc28536bf5f24f388bd701bffb98c09cd06 Mon Sep 17 00:00:00 2001
From: Tom Lane <tgl@sss.pgh.pa.us>
Date: Thu, 31 May 2001 17:32:33 +0000
Subject: [PATCH] RI triggers would fail for datatypes using old-style equal
function, because cached fmgr info contained reference to a shorter-lived
data structure. Also guard against possibility that fmgr_info could fail,
leaving an incomplete entry present in the hash table.
---
src/backend/utils/adt/ri_triggers.c | 28 +++++++++++++++++++++-------
1 file changed, 21 insertions(+), 7 deletions(-)
diff --git a/src/backend/utils/adt/ri_triggers.c b/src/backend/utils/adt/ri_triggers.c
index 71c1ccd4549..dc5f7c8495d 100644
--- a/src/backend/utils/adt/ri_triggers.c
+++ b/src/backend/utils/adt/ri_triggers.c
@@ -18,7 +18,7 @@
* Portions Copyright (c) 2000-2001, PostgreSQL Global Development Group
* Copyright 1999 Jan Wieck
*
- * $Header: /cvsroot/pgsql/src/backend/utils/adt/ri_triggers.c,v 1.24 2001/05/07 19:57:24 petere Exp $
+ * $Header: /cvsroot/pgsql/src/backend/utils/adt/ri_triggers.c,v 1.25 2001/05/31 17:32:33 tgl Exp $
*
* ----------
*/
@@ -3243,7 +3243,9 @@ ri_AttributesEqual(Oid typeid, Datum oldvalue, Datum newvalue)
if (!found)
{
HeapTuple opr_tup;
- Form_pg_operator opr_struct;
+ Oid opr_proc;
+ MemoryContext oldcontext;
+ FmgrInfo finfo;
opr_tup = SearchSysCache(OPERNAME,
PointerGetDatum("="),
@@ -3251,9 +3253,22 @@ ri_AttributesEqual(Oid typeid, Datum oldvalue, Datum newvalue)
ObjectIdGetDatum(typeid),
CharGetDatum('b'));
if (!HeapTupleIsValid(opr_tup))
- elog(ERROR, "ri_AttributesEqual(): cannot find '=' operator "
- "for type %u", typeid);
- opr_struct = (Form_pg_operator) GETSTRUCT(opr_tup);
+ elog(ERROR,
+ "ri_AttributesEqual(): cannot find '=' operator for type %u",
+ typeid);
+ opr_proc = ((Form_pg_operator) GETSTRUCT(opr_tup))->oprcode;
+ ReleaseSysCache(opr_tup);
+
+ /*
+ * Since fmgr_info could fail, call it *before* creating the
+ * hashtable entry --- otherwise we could elog leaving an incomplete
+ * entry in the hashtable. Also, because this will be a permanent
+ * table entry, we must make sure any subsidiary structures of the
+ * fmgr record are kept in TopMemoryContext.
+ */
+ oldcontext = MemoryContextSwitchTo(TopMemoryContext);
+ fmgr_info(opr_proc, &finfo);
+ MemoryContextSwitchTo(oldcontext);
entry = (RI_OpreqHashEntry *) hash_search(ri_opreq_cache,
(char *) &typeid,
@@ -3263,8 +3278,7 @@ ri_AttributesEqual(Oid typeid, Datum oldvalue, Datum newvalue)
elog(FATAL, "can't insert into RI operator cache");
entry->typeid = typeid;
- fmgr_info(opr_struct->oprcode, &(entry->oprfmgrinfo));
- ReleaseSysCache(opr_tup);
+ memcpy(&(entry->oprfmgrinfo), &finfo, sizeof(FmgrInfo));
}
/*
--
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