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Java RTS mechanism

Alan Dickinson
Greenhorn

Joined: Sep 20, 2007
Posts: 6
Hello Eric J. Bruno & Greg Bollella,

What is the underlying mechanism that provides deterministic behavior required for real-time support?
Is there a new JVM which is tied to a hard real-time clock ?

What language constructs have been added to support RTS if any?

Are there any commercial embedded systems which support Java RTS currently?

I look forward to reading your book...

Best regards,

Alan Dickinson
Eric Bruno
author
Ranch Hand

Joined: Jun 15, 2009
Posts: 60
Thanks Alan. Here are some answers:

Is there a new JVM which is tied to a hard real-time clock ?
EB: Yes, it's a separate VM (which can be downloaded at http://java.sun.com/javase/technologies/realtime/index.jsp), and requires OS support to achieve real-time behavior. Support for a high-resolution clock (nanosecond resolution) is also required. This is why Solaris 10, and only real-time Linux distributions are supported.

What language constructs have been added to support RTS if any?
EB: No changes were made to the Java language. It's a separate VM with new libraries.

Are there any commercial embedded systems which support Java RTS currently?
EB: Can you clarify? Currently Solaris 10, Red Hat MRG, and SUSE SLERT are supported.
Alan Dickinson
Greenhorn

Joined: Sep 20, 2007
Posts: 6
Thank you for the answers to my questions.
What I meant by commercial embedded systems is "hardware" vendors that support Java RTS>
But it sounds like any hardware that can run the OS's you mentioned should work?
Burk Hufnagel
Ranch Hand

Joined: Oct 01, 2001
Posts: 814
    
    3
Alan Dickinson wrote:Thank you for the answers to my questions.
What I meant by commercial embedded systems is "hardware" vendors that support Java RTS>
But it sounds like any hardware that can run the OS's you mentioned should work?

Alan,
I know there's hardware out there that supports JavaRTS, but I don't know if it's what you meant by commercially available. A couple of JavaOne's ago there was a demo of an unmanned helicopter that I believe was using Java RTS to help keep it in the air, and at an earlier one they (Boeing, I think) were displaying a drone (unmanned aircraft) that used Java RTS.
Burk


SCJP, SCJD, SCEA 5 "Any sufficiently analyzed magic is indistinguishable from science!" Agatha Heterodyne (Girl Genius)
Eric Bruno
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Ranch Hand

Joined: Jun 15, 2009
Posts: 60
I'm still a little confused by the question. The goal of the RTSJ and Java RTS is to support general purpose hardware, such as x86-based systems. The result is that Java RTS will run on any hardware approved for Solaris 10, Red Hat MRG, and SLERT. The good thing is that this means Intel x86, AMD x64, and Sun SPARC platforms. If any other processor support were desired (such as ARM or PowerPC), it would be up to Sun to port Java RTS to those processor platforms, not the other way around.
Burk Hufnagel
Ranch Hand

Joined: Oct 01, 2001
Posts: 814
    
    3
Eric Bruno wrote:I'm still a little confused by the question. The goal of the RTSJ and Java RTS is to support general purpose hardware, such as x86-based systems. The result is that Java RTS will run on any hardware approved for Solaris 10, Red Hat MRG, and SLERT. The good thing is that this means Intel x86, AMD x64, and Sun SPARC platforms. If any other processor support were desired (such as ARM or PowerPC), it would be up to Sun to port Java RTS to those processor platforms, not the other way around.

I think he's looking for something you can buy, like the Sun SPOT kits, that comes with Java RTS "burned-in" to the ROM.
Eric Bruno
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Ranch Hand

Joined: Jun 15, 2009
Posts: 60
Ok I see. Thanks Burk. Sun has a product called BlueWonder which is an Intel x86-based product running Solaris 10, in a very small and fan-less case, with specialized hardware installed for use in industrial automation. For instance, it has the Profi-bus interface and drives pre-installed, which is a standard way of interfacing with robotics and other devices used in assembly lines and manufacturing plants. It also has a unique COM port interface where the ports are not directly connect to the board (they use an optical link instead) so that if there is an electrical short from the device connected to it, it doesn't fry the whole box. This is critical for systems that control other critical systems. So, this is from Sun, and it's called BlueWonder, and you can contact Kanti.Bhabuthmal@Sun.COM for more information there.
Burk Hufnagel
Ranch Hand

Joined: Oct 01, 2001
Posts: 814
    
    3
Eric Bruno wrote:Sun has a product called BlueWonder...

BlueWonder sound pretty cool. I did a quick google, but didn't see anything on pricing. Any idea on the price range?
Eric Bruno
author
Ranch Hand

Joined: Jun 15, 2009
Posts: 60
For pricing you'll need to ask Kanti.
Burk Hufnagel
Ranch Hand

Joined: Oct 01, 2001
Posts: 814
    
    3
OK. Thanks.
Burk
 
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