Re: Directory-change notification (was Re: Desktop)

[Sri Ramkrishna <sri aracnet com>]

> I discussed this with Alan Cox and Stephen Tweedie at one point, and
> their feeling was that directory-change notification would not
> work well in the framework of select/poll, because it indicates a
> event, rather than a condition; this has a bunch of consequences,
> for instance:

What would be the point?  You wouldn't be able to duplicate this on a
SUN/AIX/HPUX box right?  How much clout do we have with these other
companies like HP, Sun and IBM?  Can changes in the Linux kernel behavior
be propogated to the other kernels?

> One possibility for a solution would be to rephrase the problem
> as "wake me when the directory has changed since last opened" (or
> since something else) rather than "wake me when the directory has 
> changed".

That would be a nice elegant solution.

> A possibility that occurs to me for dealing with that problem of
> message-queue overflows is to have a user-space daemon that is
> notified by the kernel via RT signals, has the proper fallbacks when
> overflows occur, and that then talks to the various processes using
> standard Unix-domain sockets. This solution also has the advantage
> of being easily emulated by periodic checking on systems without
> the appropriate kernel feature.  

It's something to think about..  Somewhat fairly complex solution don't
you think?

> [ P.S. - if somebody figures out a decent way to do this and
>   gets a patch into the kernel, GUI folks will be in their debt
>   forever. ] 

:-)

	sri