Re: Niches for the Hurd: evaluation method; was: DRM musings, capabilities and stuff

[olafBuddenhagen]

Hi,

On Mon, Dec 08, 2008 at 01:08:45AM +0100, Arne Babenhauserheide wrote:
> Am Freitag 05 Dezember 2008 12:40:32 schrieb Michal Suchanek:

> > If you make the POSIX layer optional then you make a sytem based on
> > capabilities, and that's what I wanted in the first place. That's
> > not how the current Hurd looks like, though.
> 
> I'll leave this one for Olaf as well. 

Well, this is all rather vague. But on generic level, I would say that
there are no distinct capability and POSIX layers in the Hurd. The
primary interface, while implemented using capabilities, is clearly
POSIX-centric. (Although you can still do many interesting things taking
advantage of it being based on capabilities.)

If you want a pure capability environment, you either have to build it
on top of the standard environment (i.e. POSIX plus Hurd extensions), or
implement it in parallel. Such a parallel implementation would be quite
isolated though, integrating rather badly with the main environment. I
still think that -- in spite of being less elegant and efficient -- the
other variant is preferable.

-antrik-