Python多进程的子进程终止问题

Question

我需要在python中使用多进程，可是我发现不论是multiprocessing.pool.Pool还是concurrent.futures.ProcessPoolExecutor都没有提供对子进程的终止？我现在急需要这样的功能，该如何实现？ 我有看ProcessPoolExecutor的源代码，ProcessPoolExecutor大概就是在submit后会把参数视为一个work_item，添加到call_queue中去，再由_process_worker取出call_item并运行，感觉也没法用hack的手段来实现终止啊。。 下面是ProcessPoolExecutor中的部分核心源代码。。 def _process_worker(call_queue, result_queue): """Evaluates calls from call_queue and places the results in result_queue. This worker is run in a separate process. Args: call_queue: A multiprocessing.Queue of _CallItems that will be read and evaluated by the worker. result_queue: A multiprocessing.Queue of _ResultItems that will written to by the worker. shutdown: A multiprocessing.Event that will be set as a signal to the worker that it should exit when call_queue is empty. """ while True: call_item = call_queue.get(block=True) if call_item is None: # Wake up queue management thread result_queue.put(os.getpid()) return try: r = call_item.fn(*call_item.args, **call_item.kwargs) except BaseException as e: exc = _ExceptionWithTraceback(e, e.__traceback__) result_queue.put(_ResultItem(call_item.work_id, exception=exc)) else: result_queue.put(_ResultItem(call_item.work_id, result=r))

Answer 1

.close() 温和地停止子进程，.terminate() 强制关。

不知道你是什么使用场景需要显式地用这种功能。我用 concurrent.futures 的时候从来没有过这种需求，直接用 with 语句。任务处理完了也就退出了。

Answer 2

###  example
import os
import signal

def handle_sigterm(signum, frame):
    # do stuff
    os._exit(0)

# subprocess
signal.signal(signal.SGITERM, handle_sigterm)

# where to kill subprocess
os.kill(pid, signal.SIGTERM)