Path: utzoo!utgpu!jarvis.csri.toronto.edu!rutgers!tut.cis.ohio-state.edu!ucbvax!hoptoad!tim
From: tim@hoptoad.uucp (Tim Maroney)
Newsgroups: comp.sys.mac.programmer
Subject: Re: Standard File and Desk Accessories
Message-ID: <7639@hoptoad.uucp>
Date: 13 Jun 89 18:02:40 GMT
References: <13855@dartvax.Dartmouth.EDU> <446@cbnewsk.ATT.COM> <9983@polya.Stanford.EDU>
Reply-To: tim@hoptoad.UUCP (Tim Maroney)
Organization: Eclectic Software, San Francisco
Lines: 27

In article <9983@polya.Stanford.EDU> kaufman@polya.Stanford.EDU
(Marc T. Kaufman) writes:
>It is EXTREMELY unlikely that Apple will try to separate code and data
>spaces in the Mac OS.  The 680x0 paging system is just not well suited to
>short, variable length segments.  It seems likely (to me) that processes will
>be protected from one another... but we're unlikely to see protection within
>a process.

I think this is an oversimplification.  It may turn out to be a correct
guess, and certainly it is less important that applications be
protected from overwriting their own code space than it is that they be
protected from writing into system space or other applications.

However, it is not neccessary to protect short, variable-length
segments to protect code resources from writing.  The Resource Manager
can readily be hacked so that code resources of various types turn up
in a separate, write-protected area, rather than in the main heap as
they do at present.  This entire code area would be protected against
writing by application code; there would be no need to lock individual
code segments.
-- 
Tim Maroney, Mac Software Consultant, sun!hoptoad!tim, tim@toad.com
Postal: 424 Tehama, SF CA 94103; Phone: (415) 495-2934

"Satanic is merely the name they give to the behavior of those who would
 disrupt the orderly way in which men want to live."
    -- Gabrielle, THE VAMPIRE LESTAT, Anne Rice