pgsql: Fix ProcWakeup() resetting wrong waitStart field. - Mailing list pgsql-committers

From Fujii Masao
Subject pgsql: Fix ProcWakeup() resetting wrong waitStart field.
Date
Msg-id E1vvOff-001AK8-0L@gemulon.postgresql.org
Whole thread Raw
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Fix ProcWakeup() resetting wrong waitStart field.

Previously, when one process woke another that was waiting on a lock,
ProcWakeup() incorrectly cleared its own waitStart field (i.e.,
MyProc->waitStart) instead of that of the process being awakened.
As a result, the awakened process retained a stale lock-wait start timestamp.

This did not cause user-visible issues. pg_locks.waitstart was reported as
NULL for the awakened process (i.e., when pg_locks.granted is true),
regardless of the waitStart value.

This bug was introduced by commit 46d6e5f56790.

This commit fixes this by resetting the waitStart field of the process
being awakened in ProcWakeup().

Backpatch to all supported branches.

Reported-by: Chao Li <li.evan.chao@gmail.com>
Author: Chao Li <li.evan.chao@gmail.com>
Reviewed-by: ji xu <thanksgreed@gmail.com>
Reviewed-by: Álvaro Herrera <alvherre@kurilemu.de>
Discussion: https://postgr.es/m/537BD852-EC61-4D25-AB55-BE8BE46D07D7@gmail.com
Backpatch-through: 14

Branch
------
REL_18_STABLE

Details
-------
https://git.postgresql.org/pg/commitdiff/0d3be050178466970644caaaa4d79848a1fcd630

Modified Files
--------------
src/backend/storage/lmgr/proc.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)


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