Proposed schedule change for JDK 9

Volker Simonis volker.simonis at
Wed Dec 2 13:48:07 UTC 2015

Hi Jeremy,

interesting points and definitely worth sharing!
I have just a single comment:

Who guarantees that we'll hit the next milestone :)
If you have any JEPs in the pipe, there's absolutely no reason to hold
them back. From my experience, keeping new features/extensions private
until "the right moment" arrives simply doesn't work. Either the right
moment will never come or somebody else will be faster with a similar
or equivalent feature and make yours obsolete. So if you have good
stuff which you want to contribute, please offensively share it,
promote it and lobby for it as soon as possible. In my opinion, that's
the only and the best way to bring new features into the OpenJDK.


On Wed, Dec 2, 2015 at 12:20 AM, Jeremy Manson <jeremymanson at> wrote:
> What constitutes a reasonable JEP in this time frame?  Is it basically
> defined as one that doesn't add undue risk to the overall release?
> I have no particular concerns about the timeline for Jigsaw features, but I
> do have concerns about the velocity of OpenJDK development.  If larger JEPs
> are not going to be able to target Java 9, and the releases are being put
> on hold for 6 months, will this timeline shift have an effect on when the
> Mercurial repos are made available for JDK10?  Will larger JEPs be able to
> target Java 10 earlier?
> We have a couple of JEPs that we've been meaning to write, but we felt like
> we missed the Java 9 deadline, so the answer to this will inform our 2016
> plans.
> Also, will this affect the flexibility in backporting new features to
> JDK8?  We've been seeing substantial improvements from JEP-246 (targeting
> Hotspot improvements for AES-GCM), to the extent where, for many customers,
> AES-GCM went from being unusable to being usable.  "Wait until Java 9"
> takes on a very different meaning after this message.
> (Perhaps also of academic interest to the community: the more that JDK9
> diverges from JDK8, the harder it will be for us either to maintain our
> patchsets against both (or to forward port the changes when JDK9 is
> ready).  From that perspective, this sort of delay somewhat works against
> us.  I imagine this is true of other organizations that maintain their own
> forks.  I'm not crazy enough to expect this to affect the decision: I'm
> just saying it because I think it might be of academic interest to the
> readership of this list.)
> Jeremy
> On Tue, Dec 1, 2015 at 9:08 AM, <mark.reinhold at> wrote:
>> The key feature of Java 9 is Project Jigsaw [1], which will introduce a
>> standard module system and use that system to modularize both the Java
>> SE Platform and the JDK.  This large project consists of a JSR for the
>> module system plus five JEPs, for the implementation of the module
>> system and for other changes specific to the JDK.
>> We've made good progress on Jigsaw over the last eighteen months: We
>> reorganized the source code into modules in August 2014 (JEP 201 [2]),
>> restructured run-time images to support modules in December 2014 (JEP
>> 220 [3]), began discussions in the JSR 376 EG last February [4], and
>> published a design overview, draft specification, and EA builds in
>> September [5].  More recently we presented an integrated series of
>> talks on Jigsaw at JavaOne 2015 and Devoxx BE 2015 [6] which were very
>> well-attended and motivated many developers to download the EA builds,
>> try them out, and send feedback and suggestions.
>> In the current JDK 9 schedule [7] the Feature Complete milestone is
>> set for 10 December, less than two weeks from today, but Jigsaw needs
>> more time.  The JSR 376 EG has not yet published an Early Draft Review
>> specification, the volume of interest and the high quality of the
>> feedback received over the last two months suggests that there will
>> be much more to come, and we want to ensure that the maintainers of
>> the essential build tools and IDEs have adequate time to design and
>> implement good support for modular development.
>> For these reasons I hereby propose a six-month extension of the JDK 9
>> schedule, moving the Feature Complete (FC) milestone to 25 May 2016, the
>> General Availability (GA) milestone to 23 March 2017, and adjusting the
>> interim milestones accordingly.
>> As with previous schedule changes, the intent here is not to open the
>> gates to a flood of new features unrelated to Jigsaw, nor to permit the
>> scope of existing features to grow without bound.  It would be best to
>> use the additional time to stabilize, polish, and fine-tune the features
>> that we already have rather than add a bunch of new ones.  The later FC
>> milestone does apply to all features, however, so reasonable proposals to
>> target additional JEPs to JDK 9 will be considered so long as they do not
>> add undue risk to the overall release.
>> Comments on this proposal from JDK 9 Committers are welcome, as are
>> reasoned objections.  If no such objections are raised by 18:00 UTC next
>> Tuesday, 8 December, or if they're raised and satisfactorily answered,
>> then per the JEP 2.0 process proposal [8] this will be adopted as the
>> new schedule for JDK 9.
>> - Mark
>> [1]
>> [2]
>> [3]
>> [4]
>> [5]
>> [6]
>> [7]
>> [8]

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