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

On 11/14/24 15:13, Heikki Linnakangas wrote:
> On 09/10/2024 23:40, Heikki Linnakangas wrote:
>> I pushed the first three patches, with the new test and one of the small
>> refactoring patches. Thanks for all the comments so far! Here is a new
>> version of the remaining patches.
>>
Hi, the TAP test 001_connection_limits.pl introduced by 6a1d0d470e84
seems to have problems with valgrind :-( I reliably get this failure:

t/001_connection_limits.pl .. 3/? # Tests were run but no plan was
declared and done_testing() was not seen.
# Looks like your test exited with 29 just after 4.
t/001_connection_limits.pl .. Dubious, test returned 29 (wstat 7424, 0x1d00)
All 4 subtests passed

and tmp_check/log/regress_log_001_connection_limits says:

[23:48:44.444](1.129s) ok 3 - reserved_connections limit
[23:48:44.445](0.001s) ok 4 - reserved_connections limit: matches
process ended prematurely at
/home/user/work/postgres/src/test/postmaster/../../../src/test/perl/PostgreSQL/Test/BackgroundPsql.pm
line 154.
# Postmaster PID for node "primary" is 198592

That BackgroundPsql.pm line is this in wait_connect()

$self->{run}->pump()
until $self->{stdout} =~ /$banner/ || $self->{timeout}->is_expired;

By trial and error I found that it fails on this line 70:

push(@sessions, background_psql_as_user('regress_superuser'));

but I have no idea idea why. There are multiple similar calls a couple
lines earlier, and those work fine. And various other TAP tests with
background_sql() work fine too.

So what's so special about this particular line?

regards

--
Tomas Vondra