Subject: Re: device attachement detection from userland
To: Emmanuel Dreyfus <manu@netbsd.org>
From: Michael van Elst <mlelstv@serpens.de>
List: tech-kern
Date: 10/16/2006 18:06:55
On Mon, Oct 16, 2006 at 04:09:54PM +0200, Emmanuel Dreyfus wrote:
> Ignatios Souvatzis <is@netbsd.org> wrote:
> 
> > AmigaOS (the DOS part) used to:
> > 
> > - remind you to insert a volume into any drive when you accessed it for
> >   reading/writing and it wasn't available
> > 
> > - remind you to insert a volume INTO (the) DRIVE ${where it was before,}
> >   (dammit, right now!) if some metadata weren't written yet when you removed
> >   it.
> 
> MacOS did that too, but how does that fit with Unix non interractive
> processes?

AmigaOS processes could tell the system to
a) use a default mechanism for the request
b) communicate the request to the application (i.e. display the request in
   an application window).
c) fail the I/O operation.

In UNIX you would
a) let the kernel send requests to a daemon process
b) register a user program with the daemon to deliver and answer the request.
c) fail the I/O operation if the daemon or user program is not running.


-- 
                                Michael van Elst
Internet: mlelstv@serpens.de
                                "A potential Snark may lurk in every tree."