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From: mss@dartvax.UUCP (Mark Sherman)
Newsgroups: net.micro.mac
Subject: Coroutines (and tasks) for the Macintosh
Message-ID: <3685@dartvax.UUCP>
Date: Thu, 10-Oct-85 17:16:01 EDT
Article-I.D.: dartvax.3685
Posted: Thu Oct 10 17:16:01 1985
Date-Received: Sun, 13-Oct-85 04:10:10 EDT
Reply-To: mss@dartvax.UUCP (Mark Sherman)
Organization: Dartmouth College, Hanover, NH
Lines: 19

People who are desparate for coroutines can have a copy of a Lisa Pascal Unit
that I wrote which provides tasking and coroutines for Macintosh programs
cross developed on the Lisa. Beware of two kludges. The first is that the
task scheduler is nonpreemptive -- I based the design on the "light-weight
tasking package" which exists in many flavors for various Xerox and IBM
PC-like machines. You must call "yield" when a task is willing to relinquish
control, sort of like "SystemTask" which everyone knows and loves. Second,
as a compatibility measure with Pascal types, all coroutines and tasks must
have a signature compatible with:
	FUNCTION MyTask(Input:PTR): PTR;
The idea is that you can pass a pointer to whatever block of information
you want. In fact, any 4-byte sized thing will do. You might pass/return a
Longint, or pass a variable by refernece, and all the "right" things will
happen.

Unfortunately, I am still writing documentation and  demo programs to
illustrate the package -- all I have for now is my test pogram which tries
out various calls in various ways. If there is sufficient interest, I'll
post the Unit sources to the net.