如何优雅的通知 multiprocessing.Pool 中的进程退出？

目的是想在主进程中随时终止子进程的执行 目前的代码长这样 有个问题是如果我 Ctrl-C 的话 所有的子进程虽然会正常退出 但是主进程会一直挂起在 pool.join()上 求解决方案~

#!/usr/bin/env python2

from __future__ import print_function

import time
import signal
import logging
from multiprocessing import Manager
from multiprocessing.pool import Pool
from multiprocessing.queues import Queue


def Fn(n, q, ns):
  if ns.done:
    return
  try:
    q.put(n)
  finally:
    return


def main():
  handler = signal.signal(signal.SIGINT, signal.SIG_IGN)
  pool = Pool(processes=5)
  signal.signal(signal.SIGINT, handler)

  total = 10000
  manager = Manager()
  q = manager.Queue()
  ns = manager.Namespace()
  ns.done = False

  for n in range(total):
    pool.apply_async(Fn, args=(n, q, ns))
  pool.close()
  try:
    received = 0
    while received != total:
      n = q.get(60)
      print('get {} from queue'.format(n))
      received += 1
  except KeyboardInterrupt:
    ns.done = True
    pass
  finally:
    pool.join()


if __name__ == '__main__':
  main()