何鑫思想是:
decorator是多线程安全的
看如下代码, 思想就是
让线程A进入decorator并loop, 首先打印pause
让线程B进入decorator, 如果打印, 证明是线程安全的

import multiprocessing
import threading
import time
import os

def decorator(func):
	def _inner(*args, **kwargs):
		while args[0].status == 0:
			print threading.current_thread().ident, 'pause'
			time.sleep(5)
		func(*args, **kwargs)
	return _inner


class A(threading.Thread):

	def __init__(self):
		super(A, self).__init__()
		self.status = 1

	def pause(self):
		self.status = 0
		print threading.current_thread().ident, 'receive pause'

	def recover_form_pause(self):
		self.status = 1

	def run(self):
		print threading.current_thread().ident, 'start'
		time.sleep(1)
		self.func1()

	@decorator
	def func1(self):
		print threading.current_thread().ident, 'func1'
		time.sleep(1)
		self.func2()

	@decorator
	def func2(self):
		print threading.current_thread().ident, 'func2'
		time.sleep(1)
		self.func3()

	@decorator
	def func3(self):
		print threading.current_thread().ident, 'func3'
		self.func1()
		time.sleep(1)


if __name__ == '__main__':
	print 'main thread', threading.current_thread().ident

	p1 = A()
	p1.start()
	p1.pause()

	time.sleep(2)

	p2 = A()
	p2.start()
	p2.pause()

	# p1.recover_form_pause()
	# p2.recover_form_pause()