async callback from threads with Tornado

gistfile1.py

import functools
import time
import threading
import logging
import Queue
import hunspell

import tornado.web
import tornado.websocket
import tornado.locale
import tornado.ioloop
from tornado.options import define, options

define('debug', type=bool, default=False, help='run in debug mode with autoreload (default: false)')

class Handler(tornado.web.RequestHandler):
    @property
    def queue(self):
        return self.application.queue

    @tornado.web.asynchronous
    def get(self, word):
        self.queue.put( (word, self.on_callback) )

    def on_callback(self, output):
        self.write("Thread output: %s" % output)
        self.finish()

class ThreadWord(threading.Thread):
    def __init__(self, queue):
        threading.Thread.__init__(self)
        self.queue = queue
        self.hobj = hunspell.HunSpell('./fr-classique.dic', './fr-classique.aff')

    def run(self):
        while True:
            try:
                word, callback = self.queue.get(True, 1)
            except Queue.Empty:
                continue
            # cpu intensive work ...
            output = self.hobj.spell(word)
            tornado.ioloop.IOLoop.instance().add_callback(functools.partial(callback, output))
            self.queue.task_done()

class Application(tornado.web.Application):
    def __init__(self):
        handlers = [
            (r"/(.*)", Handler),
        ]
        settings = {
            'cookie_secret': 'W/wT5ndaR/2sa3m8OOQ5q0xDvnZclE4BtimO1f+QM2Y=',
            'debug':options.debug,
        }
        tornado.web.Application.__init__(self, handlers, **settings)

        self.queue = Queue.Queue()

        for i in range(5):
            t = ThreadWord(self.queue)
            t.setDaemon(True)
            t.start()

if __name__ == "__main__":
    tornado.options.parse_command_line()
    application = Application()
    application.listen(8888)
    tornado.ioloop.IOLoop.instance().start()