Filesystem notification, part 2: A deeper investigation of inotify

OS X's solution to the overflow problem is to occasionally just notify for the parent directory (or the grandparent, or etc), 'coalescing' all the updates for the children. The updates are also logged in a persistent file.

As an application programmer, the coalescing turned out to be the normal case, and it was actually far more annoying to figure out what was going on on an OS X filesystem than it was to have a lightweight thing that got inotify'd and dumped events on a queue.

You could never do anything clever on application restart though.