Make tornado works with asyncio

index.md

tornado has its own event loop which is incompatible with asyncio's event loop. But it can be solved.

First, create a BaseHandler extended from tornado.web.RequestHandler:

class BaseHandler(tornado.web.RequestHandler):

    @staticmethod
    def asyncio_task(method):
        @functools.wraps(method)
        async def wrapper(self, *args, **kwargs):
            tornado_task = method(self, *args, **kwargs)
            return await asyncio.ensure_future(tornado_task)

        return wrapper

Second, decorate every http functions such as get or post with this decorator.

class MainHandler(BaseHandler):

    @BaseHandler.asyncio_task
    async def get(self):
        return self.render("index.html")

Finally, run tornado server in this way.

import asyncio
from server import make_app
from tornado.platform.asyncio import AsyncIOMainLoop

if __name__ == '__main__':
    AsyncIOMainLoop().install()
    app = make_app()
    app.listen(options.port)
    asyncio.get_event_loop().run_forever()