互斥锁

互斥锁：对共享数据进行锁定，保证同一时刻只有一个线程去操作

注意：互斥锁是多个线程一起抢。抢到锁的线程先执行

互斥锁的使用

1. 互斥锁的创建：mutex = threading.Lock()
2. 上锁：mutex.acquire()
3. 释放锁：mutex.release()

# 全局变量
import threading
import time

g_num = 0

# 对g_num进行加操作
def sum_num1():
    # 上锁
    mutex.acquire()
    for i in range(1000000):
        global g_num
        g_num += 1
    # 解锁
    mutex.release()
    print(f'g_num1: {g_num}')

# 对g_num进行加操作
def sum_num2():
    # 上锁
    mutex.acquire()
    for i in range(1000000):
        global g_num
        g_num += 1
    # 解锁
    mutex.release()
    print(f'g_num2: {g_num}')

if __name__ == '__main__':
		
		# 创建锁
		mutex = threading.Lock()

    # 创建子线程
    sum1_thread = threading.Thread(target=sum_num1())
    sum2_thread = threading.Thread(target=sum_num2())

    # 启动线程
    sum1_thread.start()
    time.sleep(1)
    sum2_thread.start()