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From: Paul Rubin <no.email@nospam.invalid>
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Subject: Re: Languages don't  matter.  A mathematical refutation
Date: Sat, 04 Apr 2015 12:20:39 -0700
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Dennis Lee Bieber <wlfraed@ix.netcom.com> writes:
>>How big and complicated do those programs tend to be, if you don't mind
>>my asking?  Do they have a lot of complex decision paths?
> 	It's not decision paths so much as deterministic timing... If there is
> a possibility of an operation triggering an arbitrary garbage collection

Yes, I can understand why a realtime system can't use gc.  Writing
simple programs without gc isn't too difficult.  Writing complicated
programs without gc often means spending a lot of effort on manual
memory management and debugging memory errors.  So I'm wondering if the
programs you wrote that way were complicated and if yes, how you dealt
with this issue.

> (even if it is nothing more than combining adjacent free block into a
> single available block) then the operation is not permitted, on the simple
> basis that it makes the timing uncertain.

In this case you may also have to consider the non-deterministic effects
of cache misses, if your cpu has cache memory; similarly for pipeline
stalls, serial multipliers, etc.