Re: real-time Java

[Robert A Duff <bobduff@shell01.TheWorld.com>]

Wesley Groleau <wesgroleau@despammed.com> writes:

> Don't know much about it, but I read more than a year ago
> that some company had a JVM with "guaranteed deterministic"
> timing.

I wonder if the machine it runs on (I mean the real one, not the virtual
one) has a cache.

Also, I don't think "deterministic" is quite what you want.
You want some practical way of predicting a worst-case (bounded)
time during which GC locks out other tasks.

> How about a garbage collector in a lower priority
> task that runs continuosly for some percentage of
> CPU time instead of hogging the machine only when
> desperately needed?

That sort of thing can be done, but any GC is going to need *some*
amount of time to do stuff that can't be interrupted.  Designs that
reduce such times often increase the overall overhead, so there's
a tradeoff.

- Bob