bittorrent/libutp — pull request #58 by arvidn (2013-09-16 21:11:41+00:00)
Title: defer writable

defer notifying the upper layer of the socket becoming writable until th...e underlying UDP socket is drained. saves CPU but batching work better.

Given that the upper layer in uTorrent does quite a lot of work every time it's notified of the socket being writable, this can save significant CPU usage.