OUTER: for (1) {
    for my $job (@jobs) {
        my ($status, $task) = $job->{job}->get_task();
        if ($status eq 'wait') {
            if ($self->{one_by_one}) {
                return 'wait';
            } else {
                return 'wait' unless --$maxcnt;
            }
        }
        elsif ($status eq 'done') {
            ($s, $t) = do_finish($job); # do_finish deletes from @jobs
            redo OUTER if $s eq 'ok';
            return ($s,$t); # (else)
        } else {
            my $newtask = Package->new(...);
            return ($status, $newtask);
        }
    }
}
return('wait')