python多线程下的信号处理程序示例

下面是一个网上转载的实现思路，经过验证，发现是可行的，就记录下来。

思路

python多线程中要响应Ctrl+C的信号以杀死整个进程，需要：

1.把所有子线程设为Daemon；
2.使用isAlive()函数判断所有子线程是否完成，而不是在主线程中用join()函数等待完成；
3.写一个响应Ctrl+C信号的函数，修改全局变量，使得各子线程能够检测到，并正常退出。

源码

#!/usr/bin/env python
#encoding: utf-8
#filename: signal_demo.py

import threading, signal


def do_job(i, step):
    global exited
    idx = i
    while not exited:
        if(idx < 10000000):
            print 'thread[%d]: idx=%d' % (i, idx)
            idx = idx + step
        else:
            break
    if exited:
        print 'receive a signal to exit, thread[%d] stop.' % i
    else:
        print 'thread[%d] complete.' % i

def sig_handler(sig, frame):
    global exited
    exited = True
    print 'receive a signal %d, exited=%d' % (sig, exited)

def main():
    #set signal handler
    signal.signal(signal.SIGTERM, sig_handler)
    signal.signal(signal.SIGINT, sig_handler)
    pool = []
    pool_size = 50
    for i in range(pool_size):
        t = threading.Thread(target = do_job, args = (i, pool_size))
        t.setDaemon(True)
        pool.append(t)
        t.start()
    while 1:
        alive = False
        for i in range(pool_size):
            alive = alive or pool[i].isAlive()
            if alive == True:
                break
        if not alive:
            break

if __name__ == '__main__':
    exited = False
    main()

命令行运行

python signal_demo.py

截图

参考文献

[1].http://www.jb51.net/article/35165.htm