my $job;

    my @jobsStarted;

    
        my @jobs = $db->resultset('Builds')->search(

        # Get the system types for the runnable builds.
        my @systemTypes = $db->resultset('Builds')->search(

            {join => 'schedulingInfo', order_by => ["priority", "timestamp"]});

            {join => 'schedulingInfo', select => [{distinct => 'system'}], as => ['system']});

        print "# of available jobs: ", scalar(@jobs), "\n";

        # For each system type, select up to the maximum number of
        # concurrent build for that system type.  Choose the highest
        # priority builds first, then the oldest builds.
        foreach my $system (@systemTypes) {
            # How many builds are already currently executing for this
            # system type?
            my $nrActive = $db->resultset('Builds')->search(
                {finished => 0, busy => 1, system => $system->system},
                {join => 'schedulingInfo'})->count;

        if (scalar @jobs > 0) {
            $job = $jobs[0];
            $logfile = getcwd . "/logs/" . $job->id;
            unlink $logfile;
            $job->schedulingInfo->busy(1);
            $job->schedulingInfo->locker($$);
            $job->schedulingInfo->logfile($logfile);
            $job->schedulingInfo->update;
            $job->buildsteps->delete_all;
        }

            # How many extra builds can we start?
            my $maxActive = 2;
            my $extraAllowed = $maxActive - $nrActive;
            $extraAllowed = 0 if $extraAllowed < 0;
            # Select the highest-priority builds to start.
            my @jobs = $extraAllowed == 0 ? () : $db->resultset('Builds')->search(
                { finished => 0, busy => 0, system => $system->system },
                { join => 'schedulingInfo', order_by => ["priority DESC", "timestamp"],
                  rows => $extraAllowed });
            print "system type `", $system->system,
                "': $nrActive active, $maxActive allowed, ",
                "starting ", scalar(@jobs), " builds\n";

            foreach my $job (@jobs) {
                $logfile = getcwd . "/logs/" . $job->id;
                unlink $logfile;
                $job->schedulingInfo->busy(1);
                $job->schedulingInfo->locker($$);
                $job->schedulingInfo->logfile($logfile);
                $job->schedulingInfo->update;
                $job->buildsteps->delete_all;
                push @jobsStarted, $job;
            }
        }

    # Start the job.  We need to do this outside the transaction in
    # case it aborts or something.
    if (defined $job) {

    # Actually start the builds we just selected.  We need to do this
    # outside the transaction in case it aborts or something.
    foreach my $job (@jobsStarted) {

                _exit(1);

                POSIX::_exit(1);