ConnectionError: Tried to read from non-existent connection

gistfile1.py

import tornadoredis
import tornado.httpserver
import tornado.ioloop
import tornado.web
import tornado.gen



class Handler(tornado.web.RequestHandler):
    
    def initialize(self):
        self.rd = tornadoredis.Client()
        self.rd.connect()


    @tornado.web.asynchronous
    @tornado.gen.engine
    def get(self):
        self.chanel = "test"

        yield tornado.gen.Task(self.rd.subscribe, self.chanel)
        print "subscribed"

        self.rd.listen(self.on_message)
        

    def on_message(self, msg):
        print "onmessage: %s" % msg.__dict__
        if msg.kind == "message":
            print "message: %s" % msg.body
            self.write(msg.body)
            self.finish()


    def on_finish(self):
        self.rd.unsubscribe(self.chanel)
        self.rd.disconnect()





if __name__ == "__main__":
    app = tornado.web.Application([(r"/", Handler),], debug=True)
    
    http_server = tornado.httpserver.HTTPServer(app)
    http_server.listen(8888)
    tornado.ioloop.IOLoop.instance().start()