多线程中同步-异步---生产者与消费者-Queue---ThreadLocal实现局部变量保存

同步：协同步调，按次序执行

异步：互相不等待，没有顺序

python2与python3中queue引用的模块不同

多线程中生产者与消费者

#encoding=utf-8
import threading
import time

#python2中
from Queue import Queue

#python3中
# from queue import Queue

class Producer(threading.Thread):
def run(self):
global queue
count = 0
while True:
if queue.qsize() < 1000:
for i in range(100):
count = count +1
msg = '生成产品'+str(count)
queue.put(msg)
print(msg)
time.sleep(0.5)

class Consumer(threading.Thread):
def run(self):
global queue
while True:
if queue.qsize() > 100:
for i in range(3):
msg = self.name + '消费了 '+queue.get()
print(msg)
time.sleep(1)

if __name__ == '__main__':
queue = Queue()

for i in range(500):
queue.put('初始产品'+str(i))
for i in range(2):
p = Producer()
p.start()
for i in range(5):
c = Consumer()
c.start()

ThreadLocal实现局部变量保存

import threading

# 创建全局ThreadLocal对象:
local_school = threading.local()

def process_student():
# 获取当前线
a81e
程关联的student:
std = local_school.student
print('Hello, %s (in %s)' % (std, threading.current_thread().name))

def process_thread(name):
# 绑定ThreadLocal的student:
local_school.student = name
process_student()

t1 = threading.Thread(target= process_thread, args=('dongGe',), name='Thread-A')
t2 = threading.Thread(target= process_thread, args=('老王',), name='Thread-B')
t1.start()
t2.start()
t1.join()
t2.join()

全局变量local_school就是一个ThreadLocal对象，每个Thread对它都可以读写student属性，但互不影响。你可以把local_school看成全局变量，但每个属性如local_school.student都是线程的局部变量，可以任意读写而互不干扰，也不用管理锁的问题，ThreadLocal内部会处理。