@我好像贝壳 ， 还记得操作系统里讲的P/V操作、生产者/消费者问题、信号量巴拉巴拉的东西么？那个时候是用伪代码写的，无聊就用python实现一下了(纯属水贴)：
+--------------------------------------------------Code-I-------------------------------------------------+
__author__ = 'streethacker'
#-*- coding: utf-8 -*-
import threading
import time
product = None
con = threading.Condition()
class Producer(threading.Thread):
def __init__(self):
super(Producer, self).__init__()
def run(self):
global product, con
if con.acquire():
while True:
if product is None:
print "producing..."
product = "something"
con.notify()
con.wait()
time.sleep(2)
class Consumer(threading.Thread):
def __init__(self):
super(Consumer, self).__init__()
def run(self):
global product, con
if con.acquire():
while True:
if product is not None:
print "consuming..."
product = None
con.notify()
con.wait()
time.sleep(2)
t1 = Producer()
t2 = Consumer()
t1.start()
t2.start()
+-------------------------------------------------------------------------------------------------------------+
+------------------------------------------------Code-II---------------------------------------------------+
__author__ = 'streethacker'
#-*- coding: utf-8 -*-
import threading
import time
semaphore = threading.Semaphore(2)
def func():
print "%s acquire semaphore..." % threading.currentThread().getName()
if semaphore.acquire():
print "%s get the semaphore..." % threading.currentThread().getName()
time.sleep(2)
print "%s release semaphore..." % threading.currentThread().getName()
semaphore.release()
t1 = threading.Thread(target= func)
t2 = threading.Thread(target= func)
t3 = threading.Thread(target= func)
t4 = threading.Thread(target= func)
t1.start()
t2.start()
t3.start()
t4.start()
+-------------------------------------------------------------------------------------------------------------+