[12] RFR: JDK-8209966: Update minimum boot JDK to 11

[Johan Vos]

I agree with the idea of not actively breaking things if not needed, on the
other hand I like predictability (instead of remembering that JavaFX 19
works with Java 17 but JavaFX 20 doens't work with Java 18 etc).
But from a pragmatic point, I'm ok with it.

The main difficulty in the whole minimum boot JDK is probably the classfile
format. If we now compile with JDK 11 and produce bytecode with version 55,
it won't run on JDK 10 VM's, even though there might be no API's or VM
specs that are specific to 11.
I agree that if there is no reason to make use of new API's or VM
functionality, there is no reason to make it not work on previous JDK's.

- Johan

On Wed, Sep 26, 2018 at 8:53 PM Kevin Rushforth <kevin.rushforth at oracle.com>
wrote:

>
> > So I think we should official define the JDK N-1 and JDK N but don't pro
> > actively break JDK N-2, ... if there's no real value.
>
> Perhaps your suggestion is a good compromise: if we choose this
> approach, then we would still claim support for only JDK N-1 and JDK N,
> but wouldn't go out of our way to stop it from running on JDK N-2
> unless/until there was a feature or bug fix that required something from
> JDK N-1. Given that it could break -- either because we need something
> from JDK N-2 or because of a bug that gets introduced and we no longer
> test with JDK N-2 -- application vendors wouldn't be able to rely on FX
> N working with JDK N-2.
>
> Johan: what do you think?
>
> -- Kevin
>
>
> On 9/24/2018 12:14 PM, Tom Schindl wrote:
> > Hi,
> >
> > As a general rule I'm fine with that but as outlined in another reply we
> > should only break building with older JDKs in case it really adds value.
> >
> > So I think we should official define the JDK N-1 and JDK N but don't pro
> > actively break JDK N-2, ... if there's no real value.
> >
> > Tom
> >
> > On 24.09.18 16:40, Kevin Rushforth wrote:
> >>> In general, I think developers updating from JavaFX 11-12-13 are also
> >>> capable of updating the JDK from 11-12-13, so I prefer the coupling
> >>>
> >>> 1. Allow building JavaFX N with either JDK N-1 or JDK N.
> >>>
> >> This is also my preference.
> >>
> >> -- Kevin
> >>
> >>
> >> On 9/24/2018 12:12 AM, Johan Vos wrote:
> >>>
> >>>      > And it's only going to get worse as time goes on. Would it not
> be
> >>>      > possible to support up until the last JDK LTS(Starting at 11)
> >>>      release
> >>>      > for building JavaFX? I feel like maybe that would be more
> >>>      reasonable.
> >>>
> >>>      This is a good question, and maybe in the future we might not be
> so
> >>>      quick to do this...or maybe we will.  We should discuss this
> >>>      before we
> >>>      get to this point for JavaFX 13, a little less than six months
> >>>      from now.
> >>>      The choices for the model are:
> >>>
> >>>      1. Allow building JavaFX N with either JDK N-1 or JDK N.
> >>>      2. Allow building JavaFX N with the most recent LTS or later.
> >>>
> >>>      Choice #1 will allow JavaFX to better keep pace with JDK features
> >>>      (API
> >>>      or language features). Choice #2 will allow JavaFX to build and
> >>>      run with
> >>>      the most current, stable JDK LTS at the cost of not being able to
> use
> >>>      newer JDK features.
> >>>
> >>>
> >>> One of the reasons Java is moving to a fast release cadence is because
> >>> today, this is required to stay relevant in a fast-changing landscape.
> >>> I think we need to do the same with JavaFX. We should be able to
> >>> leverage the latest and greatest advances in the JDK, since this will
> >>> allow JavaFX to move fast as well, which is required to stay relevant.
> >>>
> >>> If you want to run on the latest stable JDK LTS, the logical
> >>> consequence seems to me you use the latest stable JavaFX LTS. There is
> >>> LTS support available for both Java and JavaFX 11 and they are pretty
> >>> well aligned.
> >>>
> >>> Having said that, there is no point in moving forward just for the fun
> >>> of it. We also have to distinguish between changes in the VM or in the
> >>> core Java API's.
> >>> My opinion is that if a new feature is added to JDK N, we can really
> >>> take advantage of it in JavaFX (N+1).
> >>> In some cases, there won't be new features relevant to OpenJFX. But
> >>> even then, I don't think we can't change our rules on a per-release
> >>> case (e.g. JavaFX 14 works with Java 13 and Java 14, and even Java 12;
> >>> but JavaFX 15 works with Java 14 and Java 15 and not with Java 13).
> >>>
> >>> In general, I think developers updating from JavaFX 11-12-13 are also
> >>> capable of updating the JDK from 11-12-13, so I prefer the coupling
> >>>
> >>> 1. Allow building JavaFX N with either JDK N-1 or JDK N.
> >>>
> >>> - Johan
> >>>
> >>>
> >>>
>
>