Mine

$bgProc = Async->new(sub {generateTarball()}) || &errorReport("10");
while ($currRun) {
        if ($bgProc->ready) {
                if ($currentError = $bgProc->error) {
                        &errorReport("11");
                } else {
                        if ($bgProc->result > 0) {
                                &errorReport("12");
                        }
                }
                $currRun = 0;
        }
        sleep 1;
}
$currRun = 1;