From: Tom Lane <tgl@sss.pgh.pa.us>
To: dafoer_x@163.com
cc: pgsql-bugs@lists.postgresql.org
Subject: Re: BUG #18331: Why is the session lock (DEFAULT_LOCKMETHOD) not
 automatically released during process exit?
In-reply-to: <18331-b44b290d8d84d690@postgresql.org>
References: <18331-b44b290d8d84d690@postgresql.org>
Comments: In-reply-to PG Bug reporting form <noreply@postgresql.org>
	message dated "Mon, 05 Feb 2024 07:28:53 +0000"
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Date: Mon, 05 Feb 2024 11:04:12 -0500
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PG Bug reporting form <noreply@postgresql.org> writes:
> The comment for the function LockRelationIdForSession mentions “It will be
> removed  when UnlockRelationIdForSession() is called, or if an
> ereport(ERROR) occurs,  or if the backend exits.”
> However, the callback function ShutdownPostgres, which is triggered during
> process exit, only cleans up locks of type USER_LOCKMETHOD. Is it possible
> to automatically clean up session locks of type DEFAULT_LOCKMETHOD?

I think you are looking in the wrong place.  Normal locks are released
in the transaction-ending code.  We need the special case in
ShutdownPostgres because that's not true for user locks.

			regards, tom lane