Path: utzoo!attcan!uunet!aplcen!uakari.primate.wisc.edu!zaphod.mps.ohio-state.edu!van-bc!
From: lphillips@lpami.wimsey.bc.ca (Larry Phillips)
Newsgroups: comp.sys.amiga.tech
Subject: Re: resource tracking
Keywords: Discipline, discipline
Message-ID: <1158@lpami.wimsey.bc.ca>
Date: 19 Feb 90 11:20:14 GMT
Lines: 42
Return-Path: <lpami!lphillips>
To: van-bc!rnews

In <5178@sugar.hackercorp.com>, peter@sugar.hackercorp.com (Peter da Silva) writes:
>In article <9704@cbmvax.commodore.com> valentin@cbmvax.cbm.commodore.com (Valentin Pepelea) writes:
>> In article <5159@sugar.hackercorp.com> peter@sugar.hackercorp.com (Peter da Silva) writes:
>> >On UNIX IPC is the exception. On the Amiga, IPC is the norm. Every system
>> >call is actually a message passed to another program.
>
>> Whoa! Come on, you know better than that! I can name a huge number of system
>> calls which do not end up send a message somewhere else. In fact, I have
>> a lot of difficulty identifying the calls which actually do send a message.
>> They're pretty rare.
>
>If I interpret you correctly, you've misinterpreted me. In UNIX, message
>passing is the exception. In the Amiga, "system calls" are all messages.
>
>So you're just saying the same thing I said: in UNIX, IPC is the exception.

Hmm. Unless you have recently redefined the meaning of 'system call' and
'message', they are two quite different animals. While it is true that many
system calls eventually wrap your parameters in a message and dispatch it,
there are also many system calls that never dispatch a message.

Take the example of the Exec call DoIO. It is indeed a system call, in that no
mesage is built by the programmer. Load up the regs (or stack the parms and let
the glue load up the regs), and JSR. No message. DoIO does build a message, of
course, and ships it off to the driver, but that doesn't make DoIO() any less
of a system call. Heck, it's right there in exec.library, implemented as a
jump into a ROM routine.

Please note that I am not disputing your claim that in Unix, IPC is the
exception. Just pointing out that on the Amiga, a system call may or may not
generate a message.

-larry

--
Gallium Arsenide is the technology of the future;
  always has been, always will be.
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|   //   Larry Phillips                                                 |
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