Python Rlock实现线程同步

import threading

mylock = threading.RLock();
num = 0


class myThread(threading.Thread):
    def __init__(self, name):
        threading.Thread.__init__(self,name=name)

    def run(self):
        global num
        while True:
            mylock.acquire()
            print('%s locked, Number: %d' % (threading.current_thread().name, num))
            if num >= 4:
                mylock.release()
                print('%s released, Number: %d' % (threading.current_thread().name, num))
                break
            num += 1
            print('%s released, Number: %d' % (threading.current_thread().name, num))
            mylock.release()


if __name__ == '__main__':
    thread1 = myThread('Thread_1')
    thread2 = myThread('Thread_2')
    thread1.start()
    thread2.start()

如果多个线程共同对某个数据修改,则可能岀现不可预料的结果，为了保的正确
性，需要对多个线程进行同步。使用 Thread对象的Lock和RLock可以实现简单的线程同步。.
这两个对象都有acquire方法和relate方法，对于那些每次只允许一个线程操作的数据，可
以将其操作放到acquire和release方法之间。