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From: blarson%castor.usc.edu@USC-OBERON.ARPA.UUCP
Newsgroups: mod.computers.68k
Subject: Submission for mod-computers-68k
Message-ID: <8702210224.AA14372@castor.usc.edu>
Date: Fri, 20-Feb-87 21:24:44 EST
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Posted: Fri Feb 20 21:24:44 1987
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Path: castor.usc.edu!blarson
From: blarson@castor.usc.edu (Bob Larson)
Newsgroups: mod.computers.68k
Subject: Re: Submission for mod-computers-68k (really Nuxi fork())
Message-ID: <813@castor.usc.edu>
Date: 21 Feb 87 02:24:43 GMT
References: <8702131404.AA03521@mcrware.UUCP> <8702171750.AA05745@bobkat>
Reply-To: blarson@castor.usc.edu.UUCP (Bob Larson)
Organization: USC AIS, Los Angeles
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In article <8702171750.AA05745@bobkat> bobkat!m5d (Mike McNally (dlsh)) writes:
>I'll agree that most calls to fork() are followed soon after by an
>execve(), but not immediately.  Files might be closed or opened,
>priorities changed, and various other things might happen before the
>new program is loaded.

Os9 does let you do most of this.  The os9fork call includes priority
as an argument, and files may be handled by use of dup(), open(),
close(), etc. and the ability to specify how many file descriptors to
pass.

>And this still doesn't address the small minority of programs that
>DON'T execve() after a fork().  For example, the shell -- when it runs
>a loop in a subshell, it of course doesn't re-load itself.  It just
>calls fork() and the child runs the loop (after redirecting any
>files).

The example is one that would work well as a separate process, sharing
the program (as os9 always does) but with separate data.  I have yet
to see a program that can't be recoded to use os9 fork rather than
unix fork.  (Addmitadly, it isn't always trivial.)

>I think that lack of a real Unix fork() is THE great loss of OS9.
>(Along with lesser things like one-ended pipes, no signal queue, no
>in-core inode table for text sharing, ...)  For a CoCo, OS9 is a big
>step up.  For a 68000 system, however, I want real software.

What pipe feature is missing?  If by "text sharing" you mean multiple
users use a single copy of a program in memory, os9 ALWAYS does that.
The things I want in os9 are the various utilities, disk cashing
(which some version have), and virtual memory.


-- 
Bob Larson
Arpa: Blarson@Usc-Eclb.Arpa
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