From 8b8db01517bd688e35a70eb3a34fb0ce3c977085 Mon Sep 17 00:00:00 2001
From: Tom Lane <tgl@sss.pgh.pa.us>
Date: Thu, 9 Sep 1999 14:56:06 +0000
Subject: [PATCH] Minor improvement in SI overflow logic: try to delete expired
messages before concluding that we really have buffer overflow.
---
src/backend/storage/ipc/sinvaladt.c | 18 ++++++++++++++----
1 file changed, 14 insertions(+), 4 deletions(-)
diff --git a/src/backend/storage/ipc/sinvaladt.c b/src/backend/storage/ipc/sinvaladt.c
index 99426693cd1..1a91dde9b1c 100644
--- a/src/backend/storage/ipc/sinvaladt.c
+++ b/src/backend/storage/ipc/sinvaladt.c
@@ -7,7 +7,7 @@
*
*
* IDENTIFICATION
- * $Header: /cvsroot/pgsql/src/backend/storage/ipc/sinvaladt.c,v 1.25 1999/09/06 19:37:38 tgl Exp $
+ * $Header: /cvsroot/pgsql/src/backend/storage/ipc/sinvaladt.c,v 1.26 1999/09/09 14:56:06 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@@ -228,9 +228,19 @@ SIInsertDataEntry(SISeg *segP, SharedInvalidData *data)
/* Is the buffer full? */
if (numMsgs >= MAXNUMMESSAGES)
{
- /* Yes, so force reset */
- SISetProcStateInvalid(segP);
- return false;
+ /*
+ * Don't panic just yet: slowest backend might have consumed some
+ * messages but not yet have done SIDelExpiredDataEntries() to
+ * advance minMsgNum. So, make sure minMsgNum is up-to-date.
+ */
+ SIDelExpiredDataEntries(segP);
+ numMsgs = segP->maxMsgNum - segP->minMsgNum;
+ if (numMsgs >= MAXNUMMESSAGES)
+ {
+ /* Yup, it's definitely full, no choice but to reset */
+ SISetProcStateInvalid(segP);
+ return false;
+ }
}
/*
--
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