import time import threading loop = [4, 2] class ThreadFunc:     def __init__(self, name):         self.name = name     def loop(self, nloop, nsec):         #nloop:loop函数的名称         #nsec:系统休眠时间         print('Start loop', nloop, 'at', time.ctime())         sleep(nsec)         print('Done loop', nloop, 'at', time.ctime()) def main():     print("starting at:", time.ctime())     #ThreadFunc('loop').loop 跟一下两个式子相等     #t = ThreadFunc('loop')     #t.loop     #以下t1, t2的定义方式相等     t = ThreadFunc('loop')     t1 = threading.Thread(target = t.loop, args = ('Loop1', 4))     t2 = threading.Thread(target = ThreadFunc('loop').loop, args = ('Loop2', 2))     t1.start()     t2.start()     t1.join()     t2.join()     print('all done at:', time.ctime()) if __name__ == '__main__':     main()

threading的使用：

-直接利用threading.Thread生成Thread实例

1.t = threading.Thread(target = xxx, args = (xxx,))

2.t.start(): 启动多线程

3.t.join():等待多线程执行完成

守护线程：

-如果在程序中将子线程设置为守护线程，则子线程会在主线程结束的时候自动退出

-一般认为，守护线程不重要或者不允许离开主线程独立运行

线程常用属性：

-threading.currentThread: 返回当前线程变量

-threading.enumerate: 返回一个包含正在运行的线程的list，正在运行的线程指的是线程启动后，结束前的

-threading。activeCount：返回正在运行的线程数量，效果跟len(threading.enumerate)相同

-thr.setName: 给线程设置名字

-thr.getName：得到线程的名字

共享变量：当多个线程同时访问一个变量的时候，会产生共享变量的问题

 

import threading sum = 0 loopSum = 100000 def myAdd():     global sum, loopSum     for i in range(1, loopSum):         sum += 1 def myMinu():     global sum, loopSum     for i in range(1, loopSum):         sum -= 1 if __name__ == '__main__':     print('start.....{0}'.format(sum))     t1 = threading.Thread(target = myAdd, args = ())     t2 = threading.Thread(target = myMinu, args = ())     t1.start()     t2.start()     t1.join()     t2.join()     print('done.....{0}'.format(sum)) 锁：哪个资源需要多个线程，就锁谁

import threading sum = 0 loopSum = 100000 lock = threading.Lock() def myAdd():     global sum, loopSum     for i in range(1, loopSum):         lock.acquire() #上锁         sum += 1         lock.release() #释放锁 def myMinu():     global sum, loopsum     for i in range(1, loopSum):         lock.acquire()         sum -= 1         lock.release() if __name__ == '__main__':     print('starting.....{0}'.format(sum))     t1 = threading.Thread(target = myAdd, args = ())     t2 = threading.Thread(target = myMinu, args = ())     t1.start()     t2.start()     t1.join()     t2.join()     print('done.....{0}'.format(sum))

 

 

 

锁：哪个资源需要多个线程，就锁谁

可重入锁：可以被一个线程多次申请