epoll is a I/O event loop available on several *nix systems. Some third-party libraries to access it in Python have been available around the web, but I think it would be great to have it in stdlib.

Furthermore, it'll be available for using it in _socketmodule in place of poll, if there is an interest.

Attached a simple C version, and tests mostly extracted from twisted (where we use a pyrex version).

If it seems to be useful, I'd be glad to make the documentation.

I think it's a very useful addition to the select module. But I see a
license problem. Have you written the tests and code yourself and are
you willing to relicense the code under the Python license?

I've created my own interface modeled after the Twisted interface: #1657

I prefer to wrap the epoll control fd in an object, just like poll.