多线程同步引入锁

# _*_ coding: utf-8 _*_
__author__ = 'pythonwu'
__date__ = "2018/6/20 17:42"

import threading
import time

exitFlag = 10
class myThread(threading.Thread):
    def __init__(self,threadID,name,counter):
        threading.Thread.__init__(self)   #重写父类的__init__方法
        self.threadID = threadID
        self.name = name
        self.counter = counter

    def run(self):
        print("Starting " + self.name)
        threadLock.acquire()    #获得锁
        print_time(self.name,self.counter,3)    #执行程序
        threadLock.release()    #释放锁


def print_time(threadName,delay,counter):
    while counter:
        global exitFlag
        time.sleep(2)
        print("%s:%s" %(threadName,time.ctime(time.time())))
        counter -= 1
        exitFlag -= 1
        print(exitFlag)

threadLock = threading.Lock()
threads = []

thread1 = myThread(1,"Thread-1",1)
thread2 = myThread(2,"Thread-2",2)

thread1.start()
thread2.start()

threads.append(thread1)
threads.append(thread2)

for t in threads:
    t.join()
print("Exiting Main Thread")