Subject:	Re: Dare I say it, ,multitasking....
To:	philip AT irl DOT chch DOT cri DOT nz (PHILIP QUAIFE)
Date:	Wed, 8 Jun 1994 09:26:50 +0200 (MET DST)
From:	Henrik Storner <storner AT olicom DOT dk>
Cc:	djgpp AT sun DOT soe DOT clarkson DOT edu

Philip writes:

> Has the issue of preemptive multitasking being looked at/ discussed?
                   ^^^^^^^^^^
> 
> It appears that hadding the necessary hooks for context saving into go32 
> would be almost trivial. A resource lock on malloc and the FPU and away 
> you go.
> 
> No inferences about Mt dos, just getting multithreading going, ala "ctask22".

Adding a task switcher to go32 may be a fairly simple thing to do (I
haven't looked at the go32 sources, so I'll take your word for it), but
that does not amount to 'preemptive multitasking'. If a task decides to
do some lengthy calculation, it doesn't call on services in go32, so
there is no simple way of switching the context to another task. It would
be cooperative multitasking - like in MS-Windows - not preemptive multi-
tasking.

There is also such issues as how to allocate peripherals to the various
tasks - e.g. which task can use the console/keyboard? - that are not
easily resolved.

The closest I have come to having multitasking under DOS is Desqview/X,
but I guess you weren't looking for a commercial product. But djgpp 
works well in this environment.

Just my 0,13 kr (= $0.02).
-- 
Henrik Storner        | "Man is the best computer we can put aboard a space-
(storner AT olicom DOT dk)   |  craft ... and the only one that can be mass produced 
System Engineering    |  with unskilled labor."
Olicom Denmark        |                                   Wernher von Braun

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