线程死锁

多个线程互相等待锁，会导致死锁

 

 

import threading
import time

metalocA = threading.Lock()
metalocB = threading.Lock()

num = 0
def func1():
    for i in range(1000000):
        global num
        metalocA.acquire()
        metalocB.acquire()
        # num +=1
        print('---------func1----')
        metalocB.release()
        metalocA.release()

def func2():
    for i in range(1000000):
        global num
        metalocB.acquire()
        metalocA.acquire()
        # num +=1
        print('---------func2----')
        metalocA.release()
        metalocB.release()

def main():
    t1 = threading.Thread(target=func1)
    t2 = threading.Thread(target=func2)
    s_time = time.time()
    t1.start()
    t2.start()
    t1.join()
    t2.join()
    e_time = time.time()
    print(e_time-s_time)

if __name__ == '__main__':
    main()
    print(num)