threads and subtests

[chorankates]

sample code:

#!/usr/bin/perl -w

use strict;
use warnings;
use threads;
use Test::More qw(no_plan);

sub foo { 
    my $bar = 1;
    my $baz = 2;

    subtest 'barbaz' => sub {
         is ($bar, $baz, 'bar equals baz');
         is ($bar, $bar, 'bar equals bar');
    };

}

my $pid = fork();

if ($pid) { 
    foo();
    waitpid($pid, 0);
} 

if ($pid == 0) { 
    foo();
    exit(0);
}

If run as is, output is:

$ perl foo.pl
lock can only be used on shared values at /usr/local/share/perl/5.10.1/Test/Builder.pm line 775.
    # Child (barbaz) exited without calling finalize()
lock can only be used on shared values at /usr/local/share/perl/5.10.1/Test/Builder.pm line 775.
        (in cleanup) lock can only be used on shared values at /usr/local/share/perl/5.10.1/Test/Builder.pm line 775.
# Looks like your test exited with 29 before it could output anything.
    # Child (barbaz) exited without calling finalize()
        (in cleanup) lock can only be used on shared values at /usr/local/share/perl/5.10.1/Test/Builder.pm line 775.

If you comment out the 'subtest' line and the corresponding '};' line, you get:

$ perl foo.pl
not ok 1 - bar equals baz
not ok 1 - bar equals baz
#   Failed test 'bar equals baz'
#   Failed test 'bar equals baz'
#   at foo.pl line 11.
#   at foo.pl line 11.
#          got: '1'
#     expected: '2'
#          got: '1'
#     expected: '2'
ok 2 - bar equals bar
ok 2 - bar equals bar
1..2

As the documentation specifies, 'use threads' is before 'use Test::More', but if a subtest is involved, tests do not run as expected

[schwern]

@tokuhirom #147 was a duplicate.

[schwern]

Yep, it's a bug. Looks like something in the subtest code didn't get declared shared. Feel free to dig in.

[schwern]

I can cut this down to pretty much any subtest with threads on. The issue is the way subtest copies the Builder object, it loses the shared-ness of it's keys.

[schwern]

That should do it. It'll be in the next release coming soon.