Events\Select.php文件中最后處理同步進(jìn)程信號 pcntl_signal_dispatch();

運(yùn)行優(yōu)先級如下：

1. 如果有定時(shí)任務(wù)業(yè)務(wù)，最先運(yùn)行
2. 如果有客戶端讀寫數(shù)據(jù)，其次運(yùn)行
3. 最后才是處理信號邏輯

疑問：這樣的執(zhí)行順序，為了status 命令去查看是否有業(yè)務(wù)阻塞？

     if (!$this->scheduler->isEmpty()) {
                $this->tick();
            }

            foreach ($read as $fd) {
                $fdKey = (int)$fd;
                if (isset($this->readEvents[$fdKey])) {
                    $this->readEvents[$fdKey]($fd);
                }
            }

            foreach ($write as $fd) {
                $fdKey = (int)$fd;
                if (isset($this->writeEvents[$fdKey])) {
                    $this->writeEvents[$fdKey]($fd);
                }
            }

            foreach ($except as $fd) {
                $fdKey = (int)$fd;
                if (isset($this->exceptEvents[$fdKey])) {
                    $this->exceptEvents[$fdKey]($fd);
                }
            }

            if (!empty($this->signalEvents)) {
                // Calls signal handlers for pending signals
                pcntl_signal_dispatch();
            }