tornadod的异步代码

#!/usr/bin/env python
# -*- coding: utf-8 -*-

import tornado.httpserver
import tornado.ioloop
import tornado.options
import tornado.web
import tornado.httpclient
import tornado.gen
from tornado.concurrent import run_on_executor
# 这个并发库在python3.2版本以后自带， 在python2需要安装 sudo pip install  futures
from concurrent.futures import ThreadPoolExecutor
import time

class SleepHandler(tornado.web.RequestHandler):
executor = ThreadPoolExecutor(2)

@tornado.web.asynchronous
@tornado.gen.coroutine
def get(self):
"""
若是要实现异步并且该请求需要等待执行结果则加入yield
否则可以将yield去掉，程序会继续往下执行
"""
res = yield self.sleep()
self.write("when i sleep %s s bbb" % res)
self.finish() #@tornado.web.asynchonous装饰器时，Tornado永远不会自己关闭连接，需要显式的self.finish()关闭

@run_on_executor
def sleep(self):
time.sleep(6)
return 6

class NormalHandler(tornado.web.RequestHandler):
def get(self):
self.write("normal handler")

if __name__ == "__main__":
app = tornado.web.Application(handlers=[
(r"/sleep", SleepHandler),
(r"/normal", NormalHandler),
])
http_server = tornado.httpserver.HTTPServer(app)
http_server.listen(8888)
tornado.ioloop.IOLoop.instance().start()