I used a hard realtime JVM for a safety-critical missile-defense related application, but that was almost ten years ago. The JVMs to consider are IBM's WebSphere Real Time[1], Aicas JamaicaVM[2] (their front page shows examples of use in medical devices) and Atego (formerly Aonix) Perc[3]. Both Aicas and Atego focus on the embedded market (don't know about WebSphere RT).
See here for some background and some related links (http://www.javaworld.com/article/2906981/java-app-dev/little...). There's recently been a lot of activity around RTSJ 2.0 (real-time specification for Java)[4], JSR-282, led by Aicas, and JSR-302[5] -- also led by Aicas -- which is built on top of RTSJ and meant to support DO-178B certified, safety-critical applications. I see that JSR-302 is marked inactive[6], which means it hasn't had a milestone in the past year, but I think that the relevant JVMs already implement it (or something similar), even if it hasn't been ratified as a standard.
I can tell you that for us, at least 10 years ago, it was a remarkable success, and saved us a lot of time vs. developing in C or Ada, but that was for code running on large servers. I haven't had experience with RTSJ on embedded devices. Many others have, but I doubt they read HN.
You probably want to keep DSP in C, but for everything else Java may save you a lot of time and money.
Thanks so much for taking the time on a thoughtful response.
> I can tell you that for us, at least 10 years ago, it was a remarkable success, and saved us a lot of time vs. developing in C or Ada, but that was for code running on large servers.
To what do you attribute the time savings? I'm interested in using the JVM because I'm thinking I'll have an advantage in debugging over C. Would that be true, in your experience? Do you think that it was easier to develop using the JVM under your quality system than it would have been under C or Ada?
> I haven't had experience with RTSJ on embedded devices. Many others have, but I doubt they read HN.
Yeah... Do you know of a good mailing list or forum for embedded systems?
It's just much easier to produce correct code in Java than in C (or even Ada). The bigger and more complex the software -- the bigger the gains (it's easy to write simple/small programs in any language). We also used NASA's open-source Java PathFinder to verify parts of the code (there are model checkers for C, too, and others for Java). This paper (https://ti.arc.nasa.gov/m/groups/rse/papers/lindstrom-rtembe...) describes applying JPF to the realtime scheduling aspects of RTSJ (something we didn't do).
> Do you know of a good mailing list or forum for embedded systems?
See here for some background and some related links (http://www.javaworld.com/article/2906981/java-app-dev/little...). There's recently been a lot of activity around RTSJ 2.0 (real-time specification for Java)[4], JSR-282, led by Aicas, and JSR-302[5] -- also led by Aicas -- which is built on top of RTSJ and meant to support DO-178B certified, safety-critical applications. I see that JSR-302 is marked inactive[6], which means it hasn't had a milestone in the past year, but I think that the relevant JVMs already implement it (or something similar), even if it hasn't been ratified as a standard.
I can tell you that for us, at least 10 years ago, it was a remarkable success, and saved us a lot of time vs. developing in C or Ada, but that was for code running on large servers. I haven't had experience with RTSJ on embedded devices. Many others have, but I doubt they read HN.
You probably want to keep DSP in C, but for everything else Java may save you a lot of time and money.
[1]: http://www-03.ibm.com/software/products/en/real-time
[2]: https://www.aicas.com/
[3]: http://www.atego.com/products/atego-perc/
[4]: https://www.aicas.com/cms/en/rtsj
[5]: http://download.oracle.com/otn-pub/jcp/safety_critical-0_94-...
[6]: https://jcp.org/en/jsr/detail?id=302