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Comment by Scarbutt | Hacker News Reader

JRuby 9000 now uses native operations for much of IO and almost all of Process. This makes us the first POSIX-friendly JVM language.

Did they achieved this via JNI?

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The system is called JNR - Java Native Runtime - http://www.oracle.com/technetwork/java/jvmls2013nutter-20135.... It uses libffi, which I guess the final call is made to via JNI.

Charlie Nutter gave a great talk covering this and a lot of additional new JVM features here:

https://vimeo.com/114187541

Edit: The JNR stuff is covered around 42 minutes in.

This will prevent running JRuby 9000 in (today's) Google App Engine.

The project has been drifting away from App Engine support for some time now. See #2304.

https://github.com/jruby/jruby/issues/2304

> This will prevent running JRuby 9000 in (today's) Google App Engine.

It'll prevent running it on the current Google App Engine Java Runtime.

It won't, AFAICT, prevent running it in a Google App Engine Managed VM, which is an option on today's Google App Engine.

True, but many teams running Ruby in Managed VM will use opt to run YARV directly.

There's a pure-Java fallback that has most of the same functionality. But if you wanted precise POSIX function calls you probably weren't running on App Engine anyway.

Have you tried the pure-Java fallback on App Engine? I tried it for JRuby 1.7 and it didn't work. I haven't tried yet with 9000, have you?

We welcome GAE users of JRuby but they never seemed to be a big segment of the community. And we continue to maintain non-native IO and process logic for limited environments. If that is not sufficient for GAE, we'll work with you to make it so.

Jruby 1.7 simply doesn't work in GAE, and maybe it's not worth making it work there, which I would understand. I opened an issue a while ago (https://github.com/jruby/jruby/issues/2304) and I spent about a week trying to fix it. Each time I fixed one issue another one popped up and I gave up after hacking up JRuby beyond my comfort level.

Edit: I just want to stress, the JRuby team is amazing, and I've always been impressed with the responsiveness and openness of the team. This comment isn't meant as a critique in anyway, just a statement of fact with my experience trying to run JRuby on app engine.

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