Question

我有一个python脚本，它启动了几个进程。每个进程基本上只调用一个shell脚本：

from multiprocessing import Process
import os
import logging

def thread_method(n = 4):
    global logger
    command = "~/Scripts/run.sh " + str(n) + " >> /var/log/mylog.log"
    if (debug): logger.debug(command)
    os.system(command)

我启动了几个这些线程，这些线程意味着在后台运行。我希望在这些线程上有一个超时，这样如果超过超时，它们就会被杀死：

t = []
for x in range(10):
    try:
        t.append(Process(target=thread_method, args=(x,) ) )
        t[-1].start()
    except Exception as e:
        logger.error("Error: unable to start thread")
        logger.error("Error message: " + str(e))
logger.info("Waiting up to 60 seconds to allow threads to finish")
t[0].join(60)
for n in range(len(t)):
    if t[n].is_alive():
    logger.info(str(n) + " is still alive after 60 seconds, forcibly terminating")
     t[n].terminate()

问题是在进程线程上调用terminate（）并没有杀死已启动的run.sh脚本 - 它继续在后台运行，直到我从命令行强制终止它，或者它在内部完成。有没有办法让终止也杀死os.system（）创建的子shell？

Answer 1

您应该使用事件来通知工作人员终止，使用subprocess模块运行子进程，然后使用Popen.terminate()终止它。调用Process.terminate()将不允许其工作人员进行清理。请参阅the documentation for Process.terminate()。

Answer 2

请改为使用subprocess，其对象明确具有terminate() method。

Answer 3

在Python 3.3中，子进程模块支持超时：http://docs.python.org/dev/library/subprocess.html

有关Python 2.x的其他解决方案，请查看此主题：Using module 'subprocess' with timeout

Answer 4

基于Stop reading process output in Python without hang?：

import os
import time
from subprocess import Popen

def start_process(n, stdout):
    # no need for `global logger` you don't assign to it
    command = [os.path.expanduser("~/Scripts/run.sh"), str(n)]
    logger.debug(command) # no need for if(debug); set logging level instead
    return Popen(command, stdout=stdout) # run directly

# no need to use threads; Popen is asynchronous 
with open('/tmp/scripts_output.txt') as file:
    processes = [start_process(i, file) for i in range(10)]

    # wait at most timeout seconds for the processes to complete
    # you could use p.wait() and signal.alarm or threading.Timer instead
    endtime = time.time() + timeout
    while any(p.poll() is None for p in processes) and time.time() < endtime:
        time.sleep(.04)

    # terminate unfinished processes
    for p in processes:
        if p.poll() is None:
            p.terminate()
            p.wait() # blocks if `kill pid` is ignored

如果可用，请使用p.wait(timeout)。

通过os.system（）杀死在Process中启动的脚本

4 个答案: