From mboxrd@z Thu Jan  1 00:00:00 1970
Message-ID: <5890eb0cb7b6853fe9a78c321fcc7e5e@quanstro.net>
Date: Fri,  9 Jun 2006 17:30:35 -0500
From: quanstro@quanstro.net
To: 9fans@cse.psu.edu
Subject: Re: [9fans] gcc on plan9
In-Reply-To: <20060609222222.E4AFD294C1@mail.bitblocks.com>
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the mmu business is a red herring.  the point here is that a process
and a file are fundamentally different.  a file is a sequence of bytes.
a process is a collection of resources (threads, file descriptors, memory
segments, etc.) which are scheduled together.

i have no experience with lisp machines, but i'm fairly confident that
it is not true that s-expressions are processes.

did lisp machines even do multiprogramming?

- erik

On Fri Jun  9 17:23:28 CDT 2006, bakul+plan9@bitblocks.com wrote:
> > > Lisp machines/environments did this 25+ years ago.
> > > Everything is an s-expression is even more fun than
> > > everything is a file!
> > 
> > I don't agree. The problem with lisp is that you don't have
> > protection. Didn't you manage to bring down the whole emacs
> > by, say, implementing your CD player in elisp?. Now, in
> > Plan 9 processes are really isolated. If one of them crashes, the other
> > ones stay alive (Probably).
> 
> Isolation by MMU is a separate issue.  If you wish you can
> think of a Lisp machine as analogous to Inferno, with Lisp as
> its virtual machine language!  Also Lisp machine != emacs.
> In any case even you admit (with your parenthetical
> "Probably") that while at process level there is isolation
> you can still run into trouble as there may be higher level
> dependencies.