file system change notifications

[Jordan Hubbard]

> On Mar 12, 2015, at 6:37 AM, Guy Helmer <guy.helmer at gmail.com> wrote:
> 
> How are Darwin (OS X) fsevents implemented? It’s a been a handy interface for some of my work.

They have their own tap from the kernel and their own daemon (fseventsd) to handle coalescing and a publish/subscribe model that will feed multiple consumers without duplicating or losing events (I haven’t looked deeply into the implementation, but presumably all the cache management is there as well so that memory consumption can be kept manageable.

Maybe someone should keep a list of “OS X features we would really like in FreeBSD” (add purgeable memory and memory pressure bands to that list while you’re at it) and parcel them out as GSoC projects. :-)

- Jordan