python关闭进程_Python在关闭主进程时关闭子进程

I have have a main process that forks a number of subprocesses. I want to be able to kill these child processes off when my main process gets the kill signal. Ideally I would want to do something along the lines of:

def handler(signum, frame, pid_list):

log('Killing Process')

for pid in pid_list:

os.kill(pid, signal.SIGTERM)

os.waitpid(pid, 0) # need

sys.exit()

if __name__ == "__main__":

signal.signal(signal.SIGTERM, handler(pid_list))

But of course, that doesn't work... any suggestions?

解决方案

As @tony suggested you could set daemon=True flag on a child process created using multiprocessing module. To install it on python2.4, type: pip install multiprocessing.

The child processes won't be terminated if the main process is killed by a signal so you need to provide an appropriate signal handler:

#!/usr/bin/env python

import logging, signal, sys, time

import multiprocessing as mp # `pip install multiprocessing` on Python <2.6

class AddProcessNameFilter(logging.Filter):

"""Add missing on Python 2.4 `record.processName` attribute."""

def filter(self, r):

r.processName = getattr(r, 'processName', mp.current_process().name)

return logging.Filter.filter(self, r)

def print_dot():

while True:

mp.get_logger().info(".")

time.sleep(1)

def main():

logger = mp.log_to_stderr()

logger.setLevel(logging.INFO)

logger.addFilter(AddProcessNameFilter()) # fix logging records

# catch TERM signal to allow finalizers to run and reap daemonic children

signal.signal(signal.SIGTERM, lambda *args: sys.exit(-signal.SIGTERM))

# create daemonic child processes

processes = [mp.Process(target=print_dot) for _ in range(2)]

for p in processes:

p.daemon = True

p.start()

print_dot()

if __name__=="__main__":

mp.freeze_support()

main()