From 73852bd520c219051431a74ee511c4f29dd4baf3 Mon Sep 17 00:00:00 2001
From: Tom Lane <tgl@sss.pgh.pa.us>
Date: Fri, 3 Aug 2007 20:06:50 +0000
Subject: [PATCH] Fix some sloppiness in the recent multiple-autovacuum-worker
patch. It was not bothering to initialize is_autovacuum for regular
backends, meaning there was a significant chance of the postmaster
prematurely sending them SIGTERM during database shutdown. Also, leaving the
cancel key unset for an autovac worker meant that any client could send it
SIGINT, which doesn't sound especially good either.
---
src/backend/postmaster/postmaster.c | 22 ++++++++++++++++------
1 file changed, 16 insertions(+), 6 deletions(-)
diff --git a/src/backend/postmaster/postmaster.c b/src/backend/postmaster/postmaster.c
index 8db5b2a9afe..74d90e6f887 100644
--- a/src/backend/postmaster/postmaster.c
+++ b/src/backend/postmaster/postmaster.c
@@ -37,7 +37,7 @@
*
*
* IDENTIFICATION
- * $PostgreSQL: pgsql/src/backend/postmaster/postmaster.c,v 1.537 2007/08/02 23:39:44 adunstan Exp $
+ * $PostgreSQL: pgsql/src/backend/postmaster/postmaster.c,v 1.538 2007/08/03 20:06:50 tgl Exp $
*
* NOTES
*
@@ -130,7 +130,7 @@
* children we have and send them appropriate signals when necessary.
*
* "Special" children such as the startup, bgwriter and autovacuum launcher
- * tasks are not in this list. Autovacuum worker processes are on it.
+ * tasks are not in this list. Autovacuum worker processes are in it.
*/
typedef struct bkend
{
@@ -2705,6 +2705,7 @@ BackendStartup(Port *port)
*/
bn->pid = pid;
bn->cancel_key = MyCancelKey;
+ bn->is_autovacuum = false;
DLAddHead(BackendList, DLNewElem(bn));
#ifdef EXEC_BACKEND
ShmemBackendArrayAdd(bn);
@@ -3925,15 +3926,22 @@ StartAutovacuumWorker(void)
if (StartupPID != 0 || FatalError || Shutdown != NoShutdown)
return;
+ /*
+ * Compute the cancel key that will be assigned to this session.
+ * We probably don't need cancel keys for autovac workers, but we'd
+ * better have something random in the field to prevent unfriendly
+ * people from sending cancels to them.
+ */
+ MyCancelKey = PostmasterRandom();
+
bn = (Backend *) malloc(sizeof(Backend));
if (bn)
{
bn->pid = StartAutoVacWorker();
- bn->is_autovacuum = true;
- /* we don't need a cancel key */
-
if (bn->pid > 0)
{
+ bn->cancel_key = MyCancelKey;
+ bn->is_autovacuum = true;
DLAddHead(BackendList, DLNewElem(bn));
#ifdef EXEC_BACKEND
ShmemBackendArrayAdd(bn);
@@ -3949,7 +3957,9 @@ StartAutovacuumWorker(void)
free(bn);
}
else
- elog(LOG, "out of memory");
+ ereport(LOG,
+ (errcode(ERRCODE_OUT_OF_MEMORY),
+ errmsg("out of memory")));
/* report the failure to the launcher */
AutoVacWorkerFailed();
--
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