1. class PoolId {
  2.     public static function get($id = null) {
  3.         if ($id === null) {
  4.             $id = \Swoole\Coroutine::getCid();
  5.         }
  6.         $pid = \Swoole\Coroutine::getPcid($id);
  7.         if ($pid < 0) {
  8.             return $id;
  9.         }
  10.         return self::get($pid);
  11.     }
  12. }