Re: Alan Cox quote? (was: Re: accounting for threads)

[Mike Porter]

> But that foregoes the point that the code is far more complex and harder to
> make 'obviously correct', a concept that *does* translate well to userspace.

One point is that 'obviously correct' is much harder to 'prove' for
threads (or processes with shared memory) than you might think.
With a state machine, you can 'prove' that object accesses won't
conflict much more easily.  With a threaded or process based model,
you have to spend considerable time thinking about multiple readers
and writers and locking.

One metric I use to evaluate program complexity is how big of a
headache I get when trying to prove something "correct".
Multi-process or multi-threaded code hurts more than a well written
state machine.

Mike