From d3a4d63387b633abb78b57e67c9be6076255a157 Mon Sep 17 00:00:00 2001
From: Neil Conway <neilc@samurai.com>
Date: Thu, 12 Jan 2006 22:04:02 +0000
Subject: [PATCH] mbutils was previously doing some allocations, including
invoking fmgr_info(), in the TopMemoryContext. I couldn't see that the code
actually leaked, but in general I think it's fragile to assume that pfree'ing
an FmgrInfo along with its fn_extra field is enough to reclaim all the
resources allocated by fmgr_info(). I changed the code to do its allocations
in a new child context of TopMemoryContext, MbProcContext. When we want to
release the allocations we can just reset the context, which is cleaner.
---
src/backend/utils/mb/mbutils.c | 70 ++++++++++++++++------------------
1 file changed, 32 insertions(+), 38 deletions(-)
diff --git a/src/backend/utils/mb/mbutils.c b/src/backend/utils/mb/mbutils.c
index 3313439eb71..dc43b049c6e 100644
--- a/src/backend/utils/mb/mbutils.c
+++ b/src/backend/utils/mb/mbutils.c
@@ -4,17 +4,17 @@
* (currently mule internal code (mic) is used)
* Tatsuo Ishii
*
- * $PostgreSQL: pgsql/src/backend/utils/mb/mbutils.c,v 1.54 2006/01/11 08:43:12 neilc Exp $
+ * $PostgreSQL: pgsql/src/backend/utils/mb/mbutils.c,v 1.55 2006/01/12 22:04:02 neilc Exp $
*/
#include "postgres.h"
#include "access/xact.h"
+#include "catalog/namespace.h"
#include "miscadmin.h"
#include "mb/pg_wchar.h"
#include "utils/builtins.h"
#include "utils/memutils.h"
#include "utils/syscache.h"
-#include "catalog/namespace.h"
/*
* We handle for actual FE and BE encoding setting encoding-identificator
@@ -25,10 +25,12 @@ static pg_enc2name *ClientEncoding = &pg_enc2name_tbl[PG_SQL_ASCII];
static pg_enc2name *DatabaseEncoding = &pg_enc2name_tbl[PG_SQL_ASCII];
/*
- * Caches for conversion function info. Note that these values are
- * allocated in TopMemoryContext so that they survive across
- * transactions. See SetClientEncoding() for more details.
+ * Caches for conversion function info. These values are allocated in
+ * MbProcContext. That context is a child of TopMemoryContext,
+ * which allows these values to survive across transactions. See
+ * SetClientEncoding() for more details.
*/
+static MemoryContext MbProcContext = NULL;
static FmgrInfo *ToServerConvProc = NULL;
static FmgrInfo *ToClientConvProc = NULL;
@@ -86,22 +88,10 @@ SetClientEncoding(int encoding, bool doit)
if (doit)
{
ClientEncoding = &pg_enc2name_tbl[encoding];
-
- if (ToServerConvProc != NULL)
- {
- if (ToServerConvProc->fn_extra)
- pfree(ToServerConvProc->fn_extra);
- pfree(ToServerConvProc);
- }
ToServerConvProc = NULL;
-
- if (ToClientConvProc != NULL)
- {
- if (ToClientConvProc->fn_extra)
- pfree(ToClientConvProc->fn_extra);
- pfree(ToClientConvProc);
- }
ToClientConvProc = NULL;
+ if (MbProcContext)
+ MemoryContextReset(MbProcContext);
}
return 0;
}
@@ -134,11 +124,29 @@ SetClientEncoding(int encoding, bool doit)
if (!doit)
return 0;
- /*
- * load the fmgr info into TopMemoryContext so that it survives outside
- * transaction.
- */
- oldcontext = MemoryContextSwitchTo(TopMemoryContext);
+ /* Before loading the new fmgr info, remove the old info, if any */
+ ToServerConvProc = NULL;
+ ToClientConvProc = NULL;
+ if (MbProcContext != NULL)
+ {
+ MemoryContextReset(MbProcContext);
+ }
+ else
+ {
+ /*
+ * This is the first time through, so create the context. Make
+ * it a child of TopMemoryContext so that these values survive
+ * across transactions.
+ */
+ MbProcContext = AllocSetContextCreate(TopMemoryContext,
+ "MbProcContext",
+ ALLOCSET_SMALL_MINSIZE,
+ ALLOCSET_SMALL_INITSIZE,
+ ALLOCSET_SMALL_MAXSIZE);
+ }
+
+ /* Load the fmgr info into MbProcContext */
+ oldcontext = MemoryContextSwitchTo(MbProcContext);
to_server = palloc(sizeof(FmgrInfo));
to_client = palloc(sizeof(FmgrInfo));
fmgr_info(to_server_proc, to_server);
@@ -146,21 +154,7 @@ SetClientEncoding(int encoding, bool doit)
MemoryContextSwitchTo(oldcontext);
ClientEncoding = &pg_enc2name_tbl[encoding];
-
- if (ToServerConvProc != NULL)
- {
- if (ToServerConvProc->fn_extra)
- pfree(ToServerConvProc->fn_extra);
- pfree(ToServerConvProc);
- }
ToServerConvProc = to_server;
-
- if (ToClientConvProc != NULL)
- {
- if (ToClientConvProc->fn_extra)
- pfree(ToClientConvProc->fn_extra);
- pfree(ToClientConvProc);
- }
ToClientConvProc = to_client;
return 0;
--
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