From: "M. Edward (Ed) Borasky" <znmeb@...>
Date: 2006-09-04T04:49:27+09:00
Subject: Re: [OT] good article on threads

David Vallner wrote:
> Michal Suchanek wrote:
>> "To offer another analogy, a folk definition of insanity is to do the
>> same thing over and over again and expect the results to be different.
>> By this definition, we in fact require that programmers of
>> multithreaded systems be insane. Were they sane, they could not
>> understand their programs."
>>
> 
> As Rick DeNatale pointed out, the folk analogy is nonsense. The real
> world just isn't deterministic. But the point is valid, short of space
> rays ;), computers are deterministic systems and a using a
> nondeterministic computation model in programming means you're giving
> this advantage up.
> 
> David Vallner

Uh ... I beg to differ:

1. As Dijkstra pointed out decades ago, as soon as you have I/O
interrupts you have non-deterministic behavior.The operating system has
the right, but not necessarily the obligation, to try to make the
resulting behavior as deterministic as possible, whatever *that* means. :)

2. I'm not sure about the usefulness of truly nondeterministic models,
but using *stochastic* models for large "deterministic" systems is a
*huge* advantage in many cases. It represents the ability to say
something useful about a system's properties rather than being able to
say things like, "if every atom in the universe was a teraflop
supercomputer, I could fully analyze the behavior of a system
0.000000001 times the size of this one." :)