线程安全性问题

 

 

线程安全性问题
# 多线程环境下------肯定不可以变为单线程
# 共享变量  -------不可以
# 并发对共享变量进行修改-----可以

import threading


class MyThread(threading.Thread):
    sum = 0
    # 锁
    lock = threading.Lock()

    def run(self):
        with MyThread.lock:
            for i in range(1000000):
                MyThread.sum += 1


thread1 = MyThread()
thread2 = MyThread()
thread3 = MyThread()

thread1.start()
thread2.start()
thread3.start()

thread1.join()
thread2.join()
thread3.join()

print(MyThread.sum)