This patch is quite dated now and I have fixed many bugs since.  The feature is available in billiard and is working well but The code has diverged quite a lot from python trunk.  I will be updating billiard to reflect the changes for Python 3.4 soon (billiard is currently 3.3).

I think we can forget about taking individual patches from billiard for now,
and instead maybe merge the codebases at some point if there's interest.
we have a version of multiprocessing.Pool using async IO and one pipe per process that drastically improves performance
and also avoids the threads+forking issues (well, not the initial fork), but I have not yet adapted it to use the new asyncio module in 3.4

So suggestion is to close this and rather get a discussion going for combining our efforts.