demo.py(互斥锁):
import threading
import time
# 定义一个全局变量
g_num = 0
def test1(num):
global g_num # 全局变量可以实现线程间数据共享。也可以通过传参实现
for i in range(num):
mutex.acquire() # 上锁
g_num += 1
mutex.release() # 解锁
print("-----in test1 g_num=%d----" % g_num)
def test2(num):
global g_num
for i in range(num):
mutex.acquire() # 上锁
g_num += 1
mutex.release() # 解锁
print("-----in test2 g_num=%d=----" % g_num)
# 创建一个互斥锁,默认是没有上锁的
mutex = threading.Lock()
def main():
t1 = threading.Thread(target=test1, args=(1000000,))
t2 = threading.Thread(target=test2, args=(1000000,))
t1.start()
t2.start()
# 等待上面的2个线程执行完毕....
time.sleep(2)
print("-----in main Thread g_num = %d---" % g_num)
if __name__ == "__main__":
main()