Re: tasks, simple question

[Ehud Lamm <mslamm@mscc.huji.ac.il>]

On Mon, 15 Nov 1999, G wrote:

|What sort of role they play, so to say.  What sort of things one
|would use them for.
|

In a sense this is like asking where procedures are used. It is hard to
give a concise and complete answer.

One issue that is sometimes overlooked, but which I find very important
(in general, not just in Ada), is that tasking is one of the abstraction
mechanisms.
So types of software elements are easier to dsrcribe using multi-tasking
concepts. The ease ,  of course, depends of the specific tasking
primitives.

The usuall example I give, and which was debunked a bit on
comp.lang.functional awhile back, is of a simulation system with all kinds
of animals:
"Consider an ecological simulation system. The
system will simulate harbivores and carnivores, wonderring on a fixed
MxN grass field. The grass grows at a certain rate - so that a certain
time after a grass spot is eaten, new grass grows to fill that
spot. When a carnivore meets a harbivore, the carnvore is the only one
to walk away. Harbivores eat grass when hungry."[1]


Tasks can help you with modelling.

They also have, naturally, technical uses, from interrupt handlers to a
mapping of OS threads - but these issues I am sure will be described by
others.

[1] This is from something temporarily titled "The Little Abstractionist;
a Cacophony of Abstraction In Ada" which I am currently writing. It is an
example based tour of various kinds of software abstractions in Ada. Not
too advanced - it start with rationals, but I am trying to make it not too
dull either. 
Is such a thing publishable?I am pretty sure that the answer is no. But
anyway I have to finish writing it first...

Ehud Lamm mslamm@mscc.huji.ac.il
http://purl.oclc.org/NET/ehudlamm <== My home on the web 
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