Is this right way to call coroutine method in Tornado framework?

Question

I have WebSocketHandler in my Tornado application. I am not sure is this a right way to make code asynchronous.

class MyHandler(WebSocketHandler):
    def open(self):
        do something ...
        self.my_coroutine_method()

    @gen.coroutine
    def my_coroutine_method(self):
        user = yield db.user.find_one() # call motor asynchronous engine
        self.write_message(user)

Answer 1

Yes, this is correct. However, in some cases simply calling a coroutine without yielding can cause exceptions to be handled in unexpected ways, so I recommend using IOLoop.current().spawn_callback(self.my_coroutine_method) when calling a coroutine from a non-coroutine like this.