GracefulDeath::run PHP Method

    public function run()
    {
        $attempts = 0;
        while (true) {
            $attempts += 1;
            $lastWill = new LastWill($this->options);
            $pid = pcntl_fork();
            if ($pid >= 0) {
                if ($pid) {
                    $this->catchAndForwardSignalTo($pid);
                    $status = $this->waitUntilProcessDiesAndReturnStatus($pid);
                    $lastWill->stop();
                    list($tryAnotherTime, $result) = $this->afterChildDeathWithStatus($this->exitStatusOfLastChild($status), $attempts, $lastWill);
                    if (!$tryAnotherTime) {
                        return $result;
                    }
                } else {
                    $life = new Life($attempts);
                    $this->catchSignalsFor($life);
                    $lastWill->capture();
                    return call_user_func($this->main, $life);
                }
            }
        }
    }