Re: GSoC 2011 project proposal [Add kqueue support to GIO]

[Julio Merino <jmmv%NetBSD.org@localhost>]

On Tue, Mar 29, 2011 at 4:17 PM, David Young <dyoung%pobox.com@localhost> wrote:
> On Tue, Mar 29, 2011 at 10:41:37AM +0100, Julio Merino wrote:
>> As an example, several server packages have file-notification
>> functionality.  One that I'm using is Mediatomb: the lack of proper
>> file notifications makes it pretty much unusable because polling is a
>> very slow alternative when the trees to monitor are huge.
>
> Julio,
>
> Are you sure that kqueue supports monitoring trees?  I know that
> it's possible for to watch a directory with kqueue for nodes
> added/deleted/renamed, however, when a process watches directory x/ with
> kqueue it won't necessarily wake up if there is a change under x/y/ or
> x/y/z/.

As far as I know, you are right, kqueue won't work to monitor trees.
My understanding is that, to watch for changes to a particular tree,
you need to watch all the directories in such tree.

I hadn't thought of the need to watch whole trees being a problem
though.  I don't think this is a general case in desktop applications,
and for something like mediatomb, the amount of files to watch should
be (well, at least in my case ;-) way larger than the amount of
directories.

Does inotify support this?

An alternative solution to the "monitoring trees" problem is what OS X
does: http://arstechnica.com/apple/reviews/2007/10/mac-os-x-10-5.ars/7

-- 
Julio Merino / @jmmv