Minion.unlock() concurrency

[andrii-suse]

• Minion version: perl-Minion-10.0-1.2.noarch
• Perl version: 5.30.1, all in travis
• Operating system: opensuse:tumbleweed:20190925, travis environment

Steps to reproduce the behavior

Run test case https://github.com/andrii-suse/minion/blob/stress_lock/t/pg_minion_lock_stress.t , e.g. :
n=0; while : $((++n)); do echo $n; PERL5LIB=lib perl t/pg_minion_lock_stress.t || break; done

Expected behavior

Consistent results

Actual behavior

Test fails in ~50% cases indicating that Minion locks are not removed properly. (see test.log)
Suspected concurrency problems at

minion/lib/Minion/Backend/Pg.pm

Line 272 in 17868bd

'delete from minion_locks where id = (

test.log

In contrast to local environment, the test in travis is always failing https://travis-ci.org/andrii-suse/minion/builds/625632738

[kraih]

Can you replicate the problem without using 3rd party modules?

[andrii-suse]

Can you replicate the problem without using 3rd party modules?

I can try if you are really sure that mentioned DELETE command cannot try to delete the same row for concurrent queries.
At the same time adding 'for update' into the query andrii-suse@770c173 fixes problem for me and in travis, so I don't think that additional test cases are needed https://travis-ci.org/andrii-suse/minion/builds/625642901

[kraih]

Agreed, there should be a for update.

[kraih]

I forgot to credit you for the patch, sorry about that. 837f916...d82cf78