bug#22534: File notify broken on Windows

[Eli Zaretskii]

> From: Fabrice Popineau <fabrice.popineau@gmail.com>
> Date: Fri, 5 Feb 2016 16:34:17 +0100
> Cc: Michael Albinus <michael.albinus@gmx.de>, 22534@debbugs.gnu.org
> 
>  Hmm... actually, I might see a problem. If my reading of the test is
>  correct, it first creates 2000 files, and then issues 1000 renames,
>  which on Windows generate 2000 notifications. Together, these add up
>  to 4000, which is awfully close to the 4096 size of the Emacs input
>  event queue. So maybe the test fills up the event queue, and the
>  synchronization between the w32notify thread and the main thread stops
>  working at that point? Or maybe we are hitting on some limit of
>  Windows messages that can be enqueued?
> 
> I would have expected some Win32 function to error at some point ?

Maybe it does, and we don't check error codes?

But these are speculations.  And since all my other guesses were
wrong, this one most probably is as well.  I will look into this later
if no one beats me to it.

> Also, would it be useful to use the overlap mechanism?

Where? in reading Windows messages?