Python学习笔记393

以下代码可以直观展示加锁和不加锁时，线程运行的顺序。

#!/usr/bin/python

# -*- coding: UTF-8 -*-

import threading

import time

classMyThread(threading .Thread):

   def __init__(self,delay,name,count):

       threading .Thread.__init__(self)

       self.delay=delay

       self.name=name

       self.count=count

   def run (self):

       print('starting'+self.name )

       threadLock.acquire()

       # 获得锁，成功获得锁定后返回True

       # 可选的timeout参数不填时将一直阻塞直到获得锁定

       # 否则超时后将返回False

       print_time(self.delay ,self.name ,self.count)

       # 释放锁

       threadLock.release()

def print_time(delay,name,count):

   while count :

       time.sleep(delay )

       print("{}:{}".format(name, time.ctime(time.time())))

       count  -=1

threadLock=threading.Lock()

#创建容器（列表）

threads=[]

# 创建新线程

thread1=MyThread(1,'thread-1',3)

thread2=MyThread(2,'thread-2',3)

# 开启新线程

thread1.start()

thread2 .start()

# 添加线程到线程容器（列表）

threads .append(thread1 )

threads .append(thread2 )

# 等待所有线程完成

for t in threads :

   t.join()

print('Exiting Main Thrid')

加锁时:

startingthread-1startingthread-2

thread-1:FriOct2500:44:392019thread-1:FriOct2500:44:402019thread-1:FriOct2500:44:412019thread-2:FriOct2500:44:432019thread-2:FriOct2500:44:452019thread-2:FriOct2500:44:472019ExitingMainThrid

不加锁时：

startingthread-1startingthread-2

thread-1:FriOct2500:48:562019thread-2:FriOct2500:48:572019thread-1:FriOct2500:48:572019thread-1:FriOct2500:48:582019thread-2:FriOct2500:48:592019thread-2:FriOct2500:49:012019

ExitingMainThrid