6 Replies Latest reply: Jun 14, 2008 1:39 AM by 807557 RSS

    compatibility with 1.6

      Hi !
      When will the RTJVM be compatible with java version 1.6 + (1.7..) ?
      Are there some plans for a next release of RTJVM ?

        • 1. Re: compatibility with 1.6
          Sun Java RTS 2.1 will GA at the end of July and will be compatible with JDK 5.0u16

          We will be looking at further library level upgrades for future releases based on customer demand - as indicated by the surveys folks fill out when downloading the evaluation versions. There are no explicit timeframes for these future versions as yet.

          Are there particular 1.6 API's that you are interested in?

          David Holmes
          • 2. Re: compatibility with 1.6
            I am also interested in 1.6 compatibility. Its not the APIs, but class file compatibility. We have a large system with many components. Currently we compile and run under java1.6. There are a few modules that have RT requirements. I wish to use RTS for these modules only. These modules make use of jars that are compiled under 1.6. It would be nearly impossible for use to maintain 2 different branches of our system libraries. There for it is very important for my group to be able to use RTS with jars that were compiled under java 1.6.
            • 3. Re: compatibility with 1.6
              Is there any way these jars can be compiled with -target 1.5 ? Or are these coming from a third party that only produces a 1.6 version ? (Which is odd if there is no use of 1.6 API's). It mean even be possible to post-process them to make them appear to be 1.5 class files.

              David Holmes
              • 4. Re: compatibility with 1.6
                We use Java 1.6 for the improved memory management, tighter code, etc. We do have a few 3rd party apps that are java 1.6. It was my understanding that 1.6 brought in no new APIs, but instead made vast improvements in performance, memory management and graphics. It may be possible to compile with 1.5. However I do not know if any of the performance enhancements are due to changes in the compiler. We have seen significant gains in both memory management and performance under 1.6. I would hate to lose any gains that we have made. Due to the structure of our code, it would be difficult to maintain 2 sets of jars (1.6 and 1.5).

                Thanks for your reply.

                • 5. Re: compatibility with 1.6

                  There are always new API's in a major release :)


                  but yes a lot of the new features in 6.0 were behind the scenes - including a lot of the performance work in the Hotspot VM.

                  But you need to realize that the performance profile of the real-time VM is quite different to regular Hotspot, regardless of which level of class library API's are used. (In fact a number of the performance improvements made for Java 6 have long since been back-ported to 5.0). So even if Java RTS adds support for the 1.6 class libraries, you would still need to evaluate performance independently, taking into account your real-time requirements.

                  David Holmes
                  • 6. Re: compatibility with 1.6
                    Thanks for the quick reply.

                    I agree that I need to look carefully at the performance for each module in my system. However the problem still remains that I have a large system with over 100 or so components. Only a few of these components have realtime requirements, however they all use many of the same system libraries. Currently the entire system is compiled and run under java 1.6. it will be almost impossible to maintain 2 sets of system class files; Java 1.5 to support the RT modules and Java 1.6 for the rest. So it would be beneficial if RT was binary compatible with the latest release. I also think this will be more of a problem in the future.

                    Thanks for listening