import threading

import time

#参数定义了最多几个线程可以使用资源

semaphore = threading.Semaphore(3)#这里就是指最多有三个线程可以进行操作

def func():

    if semaphore.acquire():

        for i in range(2):

            print(threading.current_thread().getName() + "get semapore")

        time.sleep(5)

        semaphore.release()

        print(threading.current_thread().getName() + "release semaphore")

for i in range(8):

    t1 = threading.Thread(target=func,args=())

    t1.start()

 

def func2():

    print("I am running.....")

    time.sleep(3)

    print("I an done.......")

if __name__ == "__main__":

    t2 = threading.Timer(6,func2) #代表6秒之后开始启动线程func2

    t2.start()

    i = 0

    while True:

        print("{0}*********".format(i))

        time.sleep(3)

        i += 1

 

class MyThread(threading.Thread):

    def run(self):

        global num

        time.sleep(1)

        if mutex.acquire(1):

            num = num+1

            msg = self.name + " set num to "+str(num)

            print(msg)

            mutex.acquire()

            mutex.release()

            mutex.release()

def test():

    for i in range(5):

        t3 = MyThread()

        t3.start()

 

if __name__ == "__main__":

    num = 0

    mutex = threading.RLock()#可重入锁

    test()