Java 9 support

[headius]

We have not yet started testing on Java 9, and there are certain to be some interesting challenges running alongside Jigsaw.

This is a catch-all bug to get Java 9 support working by JRuby 9.2.

Here's what we know is outstanding:

• Booting up currently raises java.lang.reflect.InaccessibleObjectException, a new exception in 9 that indicates we can't setAccessible JDK classes. (84b12e7 and 677ce03)
• io/console warnings on startup (JDK9 + 1.7.x produces io/console warnings #3611)

[headius]

84b12e7 and 677ce03 fix the setAccessible problem for master and 1.7, respectively. That fix allows JRuby to at least do -e 1 and gem list on my OS X system with a recent Java 9 EA release.

[kares]

"najs" hack - was thinking about approaching Java 8 support (in Java code) by doing a core sub-module but it gets complicated maintenance hell quickly. so your approach is probably the best it gets atm.

on a related note maybe we shall at least consider dropping Java 7 for 9.2 does that sound reasonable (we could do much greater JI when compiling under 8) ?

[kares]

just seen #4112 ... so I guess Java 7 stays in the picture (for 9.2) than :(

[jordansissel]

Following up here from #4558

Running JRuby 9.1.7.0 with a bunch of --add-opens flags lets me get to a hello-world:

ruby -J--add-opens=java.base/{java.lang,java.security,java.util,java.security.cert}=ALL-UNNAMED

(This adds opens for java.lang, java.security, java.util, and java.security.cert)

[jordansissel]

Gem installation seems to fail because RubyZlib fails during installation

• RubyZlib fails during initializer:

% ruby -J--add-opens=java.base/{java.lang,java.security,java.util,java.security.cert}=ALL-UNNAMED  -e 'p org.jruby.ext.zlib.RubyZlib'
NameError: cannot initialize Java class org.jruby.ext.zlib.RubyZlib (java.lang.ExceptionInInitializerError)
  method_missing at org/jruby/javasupport/JavaPackage.java:259
          <main> at -e:1

[jordansissel]

RubyZlib calls setAccessible on java.util.zip.CRC32 , so adding java.util.zip to --add-opens works around this.

The following flags are what I'm using now to make progress testing on JRuby 9k + Java 9.

JRUBY_OPTS="$(echo -J--add-opens=java.base/{java.lang,java.security,java.util,java.security.cert,java.util.zip,java.lang.reflect,java.util.regex,java.net}=ALL-UNNAMED)"

[perlun]

Do we have any updates on this? (I haven't yet installed Java 9; the GA release was announced a couple of weeks ago.)

[headius]

JRuby 9.1.14 will work properly on Java 9, albeit with some warnings for some actions. The examples here with --add-opens flags provide a fine workaround for now, and we may have to put some of these in our executables.

The other day I ran JRuby 9.1.14 with Rails 5 on JDK9 and it was able to do everything properly without many warnings. I would say we support JDK9 well enough to close this issue.

I will open a new issue for ongoing accessibility warnings, so we can aggregate what flags are needed and get them into the launchers (or find alternative ways that don't trigger warnings).

[jordansissel]

Awesome — thank you!

…

On Tue, Oct 31, 2017 at 1:51 PM Charles Oliver Nutter < ***@***.***> wrote: Closed #4111 <#4111>. — You are receiving this because you commented. Reply to this email directly, view it on GitHub <#4111 (comment)>, or mute the thread <https://github.com/notifications/unsubscribe-auth/AAIC6mxjTxpLzt_KwidruKKnGg1R7ppVks5sx4hBgaJpZM4Jsfx0> .