How to make the function start working in asynchronous mode and give the result to the callback (tornado)?

Question

Python

Suppose there is some method that works for a very long time, it blocks all output to the tornado, the wrapper with gen .coroutine, accordingly, does not help to make this method asynchronous. How to make it work in the background and return the result of its work to the callback function?
Just as curious, how are asynchronous libraries written for tornado or asynhio?

Answer 1

I recommend reading: wiki.python.su/%D0%94%D0%BE%D0%BA%D1%83%D0%BC%D0%B...