Re: Get rid of WALBufMappingLock
Andrey Borodin <x4mmm@yandex-team.ru>
From: Andrey Borodin <x4mmm@yandex-team.ru>
To: Alexander Korotkov <aekorotkov@gmail.com>
Cc: Michael Paquier <michael@paquier.xyz>,
Tom Lane <tgl@sss.pgh.pa.us>,
Pavel Borisov <pashkin.elfe@gmail.com>,
Victor Yegorov <vyegorov@gmail.com>,
Yura Sokolov <y.sokolov@postgrespro.ru>,
"pgsql-hackers@lists.postgresql.org" <pgsql-hackers@lists.postgresql.org>,
Andres Freund <andres@anarazel.de>,
Kirill Reshke <reshke@yandex-team.ru>
Date: 2025-02-26T08:52:17Z
Lists: pgsql-hackers
> On 25 Feb 2025, at 20:19, Alexander Korotkov <aekorotkov@gmail.com> wrote: > > Hi! One little piece of code looks suspicious to me. But I was not raising concern because I see similar code everywhere in the codebase. But know Kirill asked to me explain what is going on and I cannot. This seems to be relevant… so. + while (upto >= pg_atomic_read_u64(&XLogCtl->InitializedUpTo)) // Assume ConditionVariableBroadcast() happened here, but before next line + ConditionVariableSleep(&XLogCtl->InitializedUpToCondVar, WAIT_EVENT_WAL_BUFFER_INIT); + ConditionVariableCancelSleep(); Won’t this sleep wait forever? I see about 20 other occurrences of similar code, so, perhaps, everything is fine. But I would greatly appreciate a little pointers on why it works. Best regards, Andrey Borodin.