gnu@hoptoad.uucp (John Gilmore) (05/12/89)
A recent posting recommended this book, among a list of others.
Let me second the recommendation.
The book is a collection of papers that deal in hard realtime systems.
Some are full of math, some are not. Some describe existing systems,
some are theoretical, some are for systems in design. Some concern
uniprocessors, others multiprocessors, others networks. Some are from
conferences, others from magazines, others are technical reports. They
cover a wide spectrum and there are 47 of them. While at least half
are of minimal interest to me, there are plenty that were quite useful.
I was particularly glad to find coverage of improved scheduling
algorithms (that deal with task deadlines rather than priorities)
since that was the particular problem I was trying to solve. I
find it hard to believe that most existing realtime tools (e.g.
VRTX, Rex) use priority scheduling. I'm interested in making the
GNU kernel able to deal with hard realtime events, such as
those required for support of high bandwidth, low latency hardware,
and priority scheduling would make systems that 'seem to work' but
in which there is no way to engineer them so that they WILL work.
Having written plenty of diagnostics, I realize it's quite hard to
test a system to its limits; it's a lot easier to design it to
handle a certain load, and use design tools to verify the design
before and during the building of the software. I am hoping that
we can build large parts of the GNU system this way, to guarantee
realtime response, not only to tape drives and serial ports, but
also to users typing and clicking at the user interface.
I found the tutorial at Stacey's Bookstore in SF, after searching
in vain for another book that would give an experienced programmer,
but realtime novice, this much depth as well as this much overview.
It's IEEE CS order number 819, LC# 88-70419, ISBN 0-8186-0819-6, IEEE
catalog number EH0276-6, _Tutorial: Hard Real-Time Systems_, John A.
Stankovic and Krithi Ramamritham, 1988, 618pp. Stacey's wanted $46 for it.
--
John Gilmore {sun,pacbell,uunet,pyramid,amdahl}!hoptoad!gnu gnu@toad.com
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