message: Handle failure (add event failed).
diff: @@ -947,6 +947,7 @@ bool Coroutine::socket_poll(std::unordered_map<int, socket_poll_fd> &fds, double
  return retval > 0;
  }
  + size_t tasked_num = 0;
  coro_poll_task task;
  task.fds = &fds;
  task.co = Coroutine::get_current_safe();
  @@ -960,9 +961,15 @@ bool Coroutine::socket_poll(std::unordered_map<int, socket_poll_fd> &fds, double
  else
  {
  coro_poll_task_map[i->first] = &task;
  + tasked_num++;
  }
  }
  + if (unlikely(tasked_num == 0))
  + {
  + return false;
  + }
  +
  if (timeout > 0)
  {
  task.timer = swTimer_add(&SwooleG.timer, (long) (timeout * 1000), 0, &task, socket_poll_timeout);
  