Re: Realtime Ada Conferences

[Ed Falis <falis@east.thomsoft.com>]

Robert Dewar wrote:
.
> 
> Note that these context switch times are for simulated context switching
> (i.e. threads simulation), rather than for use of operating systems
> threads. Of course that's all you will get on DOS/Windows type
> environments, so that's certainly not a criticism!

Well, for the sake of accuracy, as Robert and I agree: this is not 
"simulated threads" by any definition I can think of.  It's Ada 
intertask communication in a "bare machine environment", where the 
closest thing to a thread is an Ada task mapped over the hardware. It's 
the equivalent of say, a task or thread under VRTX or VXWorks or another 
RTOS, except that an Ada bare executive tends to have less 
functionality.

If you're talking mapping Ada tasks over threads, the biggest 
performance limitation tends to be the characteristics of the underlying 
threads implementation, as Robert pointed out.  But isn't that to some 
extent the price to paid for a richer computational environment?

- Ed
-- 
Ed Falis	
Thomson Software   falis@thomsoft.com	(617) 221-7341
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Ideological disarmament: a koan for the 21st century
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