#!/usr/bin/env python# -*- coding: utf-8 -*-import threadingimport timeclass MyThread(threading.Thread):    def run(self):        global num        time.sleep(1)        if mutex.acquire(1):            num += 1            msg = self.name + ‘ set num to ‘ + str(num)            print msg            mutex.acquire()            mutex.release()            mutex.release()num = 0mutex = threading.RLock()def test():    for i in range(5):        t = MyThread()        t.start()    t.join()    print ‘ALL DONE‘if __name__ == ‘__main__‘:    test()