Re: Allow non-superuser to cancel superuser tasks.

On Mon, Jul 15, 2024 at 09:54:43AM +0900, Michael Paquier wrote:
> Thanks.  I'll see about stressing the buildfarm tomorrow or so, after
> looking at how the CI reacts.

There were a few more things here:
1) The new test was missing from test_misc/meson.build.
2) With 1) fixed, the CI has been complaining about the test
stability, when retrieving the PID of a worker with this query:
SELECT pid FROM pg_stat_activity WHERE backend_type = 'autovacuum worker'

And it's annoying to have missed what's wrong here:
- We don't check that the PID comes from a worker waiting on an
injection point, so it could be a PID of something running, still gone
once the signals are processed.
- No limit check, so we could finish with a list of PIDs while only
one is necessary.  Windows was slow enough to spot that, spawning
multiple autovacuum workers waiting on the injection point.

After improving all that, I have checked again the CI and it was
happy, so applied on HEAD.  Let's see now how the buildfarm reacts.
--
Michael