Re: Race conditions in 019_replslot_limit.pl

Andres Freund <andres(at)anarazel(dot)de> writes:
> On 2022-02-17 21:55:21 -0800, Andres Freund wrote:
>> Isn't it pretty bonkers that we allow error processing to get stuck behind
>> network traffic, *before* we have have released resources (locks etc)?

It's more or less intentional, per elog.c:

/*
* This flush is normally not necessary, since postgres.c will flush out
* waiting data when control returns to the main loop. But it seems best
* to leave it here, so that the client has some clue what happened if the
* backend dies before getting back to the main loop ... error/notice
* messages should not be a performance-critical path anyway, so an extra
* flush won't hurt much ...
*/
pq_flush();

Perhaps it'd be sensible to do this only in debugging (ie Assert)
builds?

regards, tom lane