Antoine Pitrou: "...  I'm against this change ..."

Martin Panter: "... But this seems unreasonable to me. ..."

I close the issue. You can use asyncio for non-blocking networking code. Or have a look at Twisted, Tornado, eventlet, etc.

If you really want to hack socketserver, I suggest you to copy the whole socketserver.py file. But asynchronous programming is a hard problem which requires more than modiying a single function. Slowly, you will built something similar the the project that I cited.