Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!tut.cis.ohio-state.edu!rutgers!cbmvax.cbm.commodore.com!mitchell
From: mitchell@cbmvax.cbm.commodore.com.commodore.com (Fred Mitchell - PA)
Newsgroups: comp.sys.mac
Subject: Re: Multitasking and interactivity issues (long)
Keywords: multitasking,interactivity,personal
Message-ID: <9430@cbmvax.cbm.commodore.com.commodore.com>
Date: 23 Jan 90 06:01:49 GMT
References: <1990Jan13.105048.11530@waikato.ac.nz>
Reply-To: mitchell@cbmvax.cbm.commodore.com.commodore.com (Fred Mitchell - PA)
Organization: Commodore, West Chester, PA
Lines: 32

In article <1990Jan13.105048.11530@waikato.ac.nz> ldo@waikato.ac.nz (Lawrence D'Oliveiro) writes:
>
>MultiFinder has been accused of not having "true" multitasking,
>in that it requires applications to cooperate and not hog
>the CPU to themselves.
>...
>In summary, a personal computer system needs *cooperative*,
>not competitive, multitasking, ...

I _very strongly_ disagree. On the Amiga, you have the best example of
pre-emptive multitasking that I have ever seen on a micro. And the number
ONE thing that you have is SPEED! If my program dosen't have to make
repeated calls to the OS, it can run that much faster. I don't see any
advantages to having a 'cooperative' OS at all. It tends to get in the way,
and hints at a fundamental flaw in the initial design. I fail to understand
why Macs can't go pre-emptive anyway. All you do is save all the registers,
go to the next task, and load that task's registers, and hop right in where
it left off before! Shared resources can use semaphores to arbitrate usage.
Sound pretty simple to me! Why is that not possible under the Multi-Finder (or
Finder for that matter)?  :-(

>...not as a cut-down version of a multiuser operating system. I
>think even round-robin time-slicing (forced periodic rescheduling)
>of tasks is a bad idea; it costs CPU cycles to implement,

Not nearly as much as cooperative costs you!

Then again it's unfair to compare a personal computer to a multi-user
system. (Or is it? :-) 

	-Mitchell
	 mitchell@cbmvax.UUCP