protected function registerEventSignals()
    {
        if (!EventLoop::$instance) {
            return;
        }
        foreach (self::$signals as $no => $name) {
            if ($name === 'SIGKILL' || $name == 'SIGSTOP') {
                continue;
            }

            $ev = EventLoop::$instance->signal($no, [$this, 'eventSighandler'], [$no]);
            if (!$ev) {
                $this->log('Cannot event_set for ' . $name . ' signal');
            }
            $ev->add();
            $this->sigEvents[$no] = $ev;
        }
    }