JEP 175: Integrate PowerPC/AIX Port into JDK 8 (original) (raw)

David Holmes david.holmes at oracle.com
Mon Feb 4 03:39:08 PST 2013

On 4/02/2013 8:50 PM, Volker Simonis wrote:

On Sat, Feb 2, 2013 at 1:42 PM, David Holmes <david.holmes at oracle.com I am also hoping that this will not simply be a copy'n'modify port as we have seen in the past. The proliferation of platform ifdefs in shared code is truly horrendous; as is the duplication across the purportedly platform-specific code. This problem wasn't addressed for the Mac port but in my opinion (and that is all it is) it needs to be before the community accepts any further ports.

That would be nice but that is not and can not be the focus of this port. It would also have a much bigger impact on all the currently supported platforms than doing it in the way how all the other ports have been done until now.

I had thought that when this was proposed the issue of not doing a simple copy'n'modify, and the need for an improved architecture to allow ease of porting was raised. But it seems my recollection was incorrect.

My apologies for that. It is of course not reasonable to expect this as the port is completed.

That said I still have grave concerns about the maintainability of the codebase due to the excessive use of platform ifdefs in "shared" code, and the excessive duplication in "platform specific" code. And that each new port makes it that much harder to instigate such changes. I feel with this port we will have reached a point now where it is almost impossible to fix this. It would take significant resources to refactor the code etc, dealing with all the existing platforms, while at the same time trying to evolve the platform to Java 9.

David

That said, we would warmly welcome any initiative (maybe a JEP) for refactoring the class library to make it more portable. JDK9 may probably be the appropriate target for such a project. I'd also like to understand the proposed maintenance model going forward. We (in Oracle) already have to accommodate our closed ports when they are affected by changes to common code that requires per-platform changes as well. Who will be providing the changes needed for aix-ppc? And how will that happen?

The changesets will of course be provided by us (IBM and SAP). How this will happen is up to the OpenJDK cummunity and Oracle. Mark promised to propose a formal policy for how this may look like. Again I think the big picture issues need to discussed on jdk8-dev (or perhaps it is time to start jdk8u-dev?) before getting into changeset specifics for hotspot and core-libs. Thanks, David ----- What do you mean with "ramping up infrastructure": - hardware resources (like test/build infrastructure)? - human resources within Oracle? - human resources within IBM/SAP? I think we have most of these allocated (except the Oracle part which I can not speak about:) -phil. On 2/1/2013 5:57 AM, Volker Simonis wrote: On Fri, Feb 1, 2013 at 12:15 PM, David Holmes <david.holmes at oracle.com <mailto:david.holmes at oracle.com> _<mailto:david.holmes at oracle._com_ _<mailto:david.holmes at oracle.com>>>wrote: On 1/02/2013 8:11 PM, mark.reinhold at oracle.com <mailto:mark.reinhold at oracle.com> <mailto:mark.reinhold at oracle._com_ _<mailto:mark.reinhold at oracle.com>> wrote: Posted: http://openjdk.java.net/jeps/*__*175 <http://openjdk.java.net/jeps/*_*175> <http://openjdk.java.net/jeps/_**175_ _<http://openjdk.java.net/jeps/**175>><http://openjdk.java._net/_jeps/175_ _<http://openjdk.java.net/_jeps/175> <http://openjdk.java.net/jeps/_175_ _<http://openjdk.java.net/jeps/175>>> I'm forced to send this to porters-dev but I do not subscribe to that list (so it will probably get held up). Given the way the JEP tasks have been split it would seem much more appropriate to me for discussions to occur on hotspot-dev and core-libs-dev as this, as the JEP says, is about the integration effort not the porting effort. Yes, I agree. I just wanted to wait until the JEP was published before posting it to the appropriate lists That said this is also relevant to jdk8-dev, also cc'd, as it affects all JDK 8 development. I have trouble seeing how such a large effort can be assimilated within the timeframes of the Java 8 schedule. As previously discussed on porters-dev the current target is not the first JDK 8 release but rather the first non-security update (i.e. something like JDK 8u2) Regards, Volker David - Mark

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