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From: jbs@mit-eddie.UUCP (Jeff Siegal)
Newsgroups: net.arch
Subject: Re: Addressing modes (conditional branches)
Message-ID: <1106@mit-eddie.UUCP>
Date: Thu, 27-Feb-86 05:43:29 EST
Article-I.D.: mit-eddi.1106
Posted: Thu Feb 27 05:43:29 1986
Date-Received: Sat, 1-Mar-86 02:29:40 EST
References: <546@tekcrl.UUCP> <426@utastro.UUCP> <5681@mordor.UUCP>
Reply-To: jbs@eddie.UUCP (Jeff Siegal)
Distribution: net
Organization: MIT, Cambridge, MA
Lines: 18

In article <5681@mordor.UUCP> ehj@mordor.UUCP (Eric H Jensen) writes:
>If you allow self-modifying code everyone would have to have a
>seperate copy of their task.  Swap space is not that cheap - with a
>lot of people running emacs and maybe a lisp underneath it, kiss your
>swap area and probably system performance (unless you buy more main
>memory) goodbye....   

hmmm.  What about copy-on-write access?

>I can't see how you could effectively manage a POLICY of
>"self-modifying code is okay" in a statically linked environment.
>Every sub-system that linked in a routine that modified its own code
>would inherit the 'impure' curse.   Perhaps this would not be such
>a problem in a dynamically linked environment.

I'm not sure I understand what you are saying.  Under Unix, at least,
sub-systems are not shared.  Please explain.

Jeff Siegal - MIT EECS