#!/usr/bin/env python

 # -*- coding:utf-8 -*-

 import  Queue

 import  threading

 class ThreadPool(object):

     def __init__(self,max_num=20):

         self.queue=Queue.Queue(max_num)

         for i in xrange(max_num):

             self.queue.put(threading.Thread)

     def get_thread(self):

         return self.queue.get()

     def add_thread(self):

         return  self.queue.put(threading.Thread)

 pool = ThreadPool(10)

 def func(arg,p):

     print arg

     import time

     time.sleep(2)

     p.add_thread()

 for i in xrange(30):

     thread = pool.get_thread()

     t = thread(target=func,args=(i,pool))

     t.start()