src/Raw/Resource2Pool.php
protected function wait()
    {
        $timer = 0;
        $timeout = $this->getMaxWait();
        $interval = 50;
        $uSleep = $interval * 1000;

        while ($timer <= $timeout) {
            // 等到了可用的空闲资源
            if ($res = $this->getFreeQueue()->pop()) {
                return $res;
            }

            $timer += $interval;
            usleep($uSleep);
        }

        return false;
    }
protected function wait()
    {
        $timer = 0;
        $timeout = $this->getMaxWait();
        $interval = 50;
        $uSleep = $interval * 1000;

        while ($timer <= $timeout) {
            // 等到了可用的空闲资源
            if ($res = $this->getFreeQueue()->pop()) {
                return $res;
            }

            $timer += $interval;
            usleep($uSleep);
        }

        return false;
    }
等待并返回可用资源
@return bool|mixed