Re: Refactoring postmaster's code to cleanup after child exit

On 12/10/24 11:00, Heikki Linnakangas wrote:
> On 09/12/2024 22:55, Heikki Linnakangas wrote:
>> Not sure how to fix this. A small sleep in the test would work, but in
>> principle there's no delay that's guaranteed to be enough. A more
>> robust solution would be to run a "select count(*) from
>> pg_stat_activity" and wait until the number of connections are what's
>> expected. I'll try that and see how complicated that gets..
>
> Checking pg_stat_activity doesn't help, because the backend doesn't
> register itself in pg_stat_activity until later. A connection that's
> rejected due to connection limits never shows up in pg_stat_activity.
>
> Some options:
>
> 0. Do nothing
>
> 1. Add a small sleep to the test
>

I'd just add a short sleep. Yeah, sleeps are not great, but everything
else seems like a lot of effort just to make this one test pass under
valgrind, and I don't think it's worth it.

Can we make the sleep conditional on valgrind, so that regular builds
are not affected? I guess regular builds could fail too, but I don't
think we've seen such failures until now.

regards

--
Tomas Vondra