python多线程下的信号处理程序示例

╰半夏微凉° 2022-08-01 13:54 25阅读 0赞

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**

**![Center][]**

**参考文献**

\[1\].[http://www.jb51.net/article/35165.htm][http_www.jb51.net_article_35165.htm]

[Center]: /images/20220731/62418d91f0af426bb01620c0a64540f4.png
[http_www.jb51.net_article_35165.htm]: http://www.jb51.net/article/35165.htm