code: public function start($block = true, $interval = 100)
      {
          $loop = $this->loop;
          $this->pool = new ParallelPool(function () use ($loop) {
              $loop->run();
          }, $this->count);
  
          $this->pool->start();
          $this->pool->keep($block, $interval);
      }
docs: start multi loop
  
  @param bool $block
  @param int $interval