On Thu, Feb 25, 2010 at 1:07 AM, Gregg Wonderly <[email protected]> wrote:
> For more than a decade, there has been http://www.ajile.com out doing direct
> silicon execution of Java, complete with some microcode assist.  Their web
> site now speaks more directly at a market in the JME side of things.  The
> first version of their chip did JDK1.1.8 with some hiccups in GC that took
> some time to work out.
>
> Sun would not advertise nor support them too much for some reason. The
> original team was composed of people who left HP, Sun and other companies
> and bought the rights to the chip manufacturing from one of the companies
> (I've forgotten which one).

I have worked with the aJile chips. Also the Typhoon chips from
Velocity Semiconductors. The latter was much more performant than the
former, and could either compile down the Java to assembler (MIPS
IIRC) or do dynamic classloading on the target. aJile on the other
hand had a stronger security model, where there was actually 2
separate memory spaces, intended for "system" and "user" to ensure
full safety for a kernel. I have not looked at it recently, but I
think they are both struggling heavy from ARM architectures, which now
supports Java acceleration modules in silicon as well, which is the
obvious choice for large-volume manufacturers.

As for "real-time Jini", you need to understand the constraints, and
need to set the expectations accordingly. I am not sure that even RTSJ
is capable of delivering Jini within a predictable time frame, so the
point of bringing realtime networks to the table doesn't necessary
improve the situation (some argue that realtime networks are not
possible by definition (for instance, data corruption)). OTOH, there
are many "realtime-like" systems, I normally call them "soft
realtime", where the time constraints are not "hard", i.e. system just
temporarily degrades with failure to meet the time. For such systems,
even ordinary Java is often "good enough", if you take great care in
object allocations. Having to worry about that through-out Jini though
is probably not feasible at this stage. IIRC, RTSJ supports the
separation of a time-critical loop versus the overall "enterprisey"
functionality, and if Jini is in the later, it might work. But in that
case, again, the realtime networks brings very little value.


Cheers
-- 
Niclas Hedhman, Software Developer
http://www.qi4j.org - New Energy for Java

I  live here; http://tinyurl.com/2qq9er
I  work here; http://tinyurl.com/2ymelc
I relax here; http://tinyurl.com/2cgsug

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