7.3.4.1 - 并发多线程 互斥锁

互斥锁

把并行变成串行，保证顺序，降低效率。

from threading import Thread, Lock
import time

n = 100

def task():
    global n
    mutex.acquire()
    tmp = n
    time.sleep(0.1)
    n = tmp - 1
    print(n)
    mutex.release()

if __name__ == "__main__":
    mutex = Lock()
    t_l = []
    for i in range(100):
        t = Thread(target=task)
        t_l.append(t)
        t.start()

    for i in t_l:
        t.join()

    print("主",n)

99
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主 0