Add Minion lock stress test

.travis.yml

@@ -15,11 +15,11 @@ services:
     - postgresql
 env:
   global:
-    - HARNESS_OPTIONS=j9
+    - HARNESS_OPTIONS=j1
     - TEST_POD=1
     - TEST_ONLINE=postgresql://postgres@/minion_test
 install:
-  - cpanm -n Mojo::Pg Test::Pod Test::Pod::Coverage
+  - cpanm -n Mojo::Pg Test::Pod Test::Pod::Coverage Mojo::IOLoop::ReadWriteProcess
   - cpanm -n --installdeps .
 before_script:
   - psql -U postgres -c 'create database minion_test'

t/pg_minion_lock_stress.t

@@ -0,0 +1,56 @@
+use Mojo::Base -strict;
+use Test::More;
+
+plan skip_all => 'set TEST_ONLINE to enable this test' unless $ENV{TEST_ONLINE};
+
+use Minion;
+use Mojo::IOLoop::ReadWriteProcess qw(queue process);
+require Mojo::Pg;
+
+use Data::Dumper;
+
+my $iterations = 100;
+
+my $pg = Mojo::Pg->new($ENV{TEST_ONLINE});
+$pg->db->query('drop schema if exists minion_worker_test cascade');
+$pg->db->query('create schema minion_worker_test');
+my $minion = Minion->new(Pg => $ENV{TEST_ONLINE});
+$minion->backend->pg->search_path(['minion_worker_test']);
+
+my $q = queue;
+
+$q->pool->maximum_processes(16); # Max processes in parallel
+$q->queue->maximum_processes($iterations); # Max queue
+my $fired;
+
+$q->add( process sub {
+    my $res = $minion->lock('test_lock', 3600, {limit => 16});
+    $minion->unlock('test_lock') if $res;
+} ) for 1..$iterations;
+
+$q->once(stop => sub { $fired++; });
+
+my $locks = $minion->backend->pg->db->query(
+  "select count(*) as cnt
+   from minion_worker_test.minion_locks where name='test_lock'"
+)->hash->{cnt};
+
+is($locks, 0, 'No locks should exist');
+
+# Consume the queue
+$q->consume();
+my $all = $q->done;
+
+is($fired, $iterations, 'Number of executed events matches planned');
+print Dumper('Events not fired: ', $all) unless $fired == $iterations;
+
+$locks = $minion->backend->pg->db->query(
+  "select count(*) as cnt
+   from minion_worker_test.minion_locks where name='test_lock'"
+)->hash->{cnt};
+
+is($locks, 0, 'No locks should remain');
+
+$pg->db->query('drop schema minion_worker_test cascade');
+
+done_testing();