How can wait for events with Tornado and then pushing them back to user's web-browser trough long-polling?

I want the events to be arbitrary events, for example: "User answered X", "User P sent you a message with Q".

From stackoverflow

• I believe that you want to take a look at: http://www.tornadoweb.org/documentation#non-blocking-asynchronous-requests

  Also, take a look at the chat example app that comes packaged with Tornado.