Comments on: Distilling JRuby: Method Dispatching 101

By: Vladimir Sizikov

Vladimir Sizikov — Fri, 25 Sep 2009 19:13:21 +0000

Great stuff indeed! Exploring JRuby inner workings been always real fun for me too.

By: Ian Farbrother

Ian Farbrother — Fri, 25 Sep 2009 18:26:55 +0000

Great article. Thanks for taking the time both to research and to post.

By: Charles Oliver Nutter

Charles Oliver Nutter — Fri, 25 Sep 2009 17:56:02 +0000

I’ve finally managed to do a full read-through, and you have a very good overview of how dispatch works in JRuby. Among other goals we want to also simplify the more complex areas; for example, making the generated Invokers generate Java code instead of raw bytecode, cleaning up and simplifying the JIT process, and in general providing more visibility into the call path. We’re also always looking to improve performance, which will mean over-complex code gets in the way.

Hopefully with your explorations you’ll be closer to contributing to some of the complex areas We could always use more people who know how that stuff works!

By: tychobrailleur

tychobrailleur — Thu, 24 Sep 2009 19:10:24 +0000

Hey, Mr. Jenius,

Excellent article. I was actually looking for something else altogether, but this overview of JRuby inner workings is really interesting. Make me want to have a look myself!

Thanks.

By: R.J.

R.J. — Thu, 17 Sep 2009 13:51:35 +0000

Thank you for the read-through. Coming from you, that is a rewarding review!

I agree completely – having gone through so many of the JRuby internals – when you strip out all of the complex/scary parts, you have a very consistent and simple model of a programming languages. You guys definitely deserve some significant credit for translating the Ruby language (which all things considered is a complex creature) into such a clear and straightforward model.

What I can tell you as an outsider looking in is that the complex/scary portions of code (the auto-generated TypePopulators, the JITCompiler, the FastOp call sites, the pre-compiled Java method dispatches) are generally well quarantined from the main code flow – it’s easy to tell when you wander in to bat country!

Good work!

By: Charles Oliver Nutter

Charles Oliver Nutter — Thu, 17 Sep 2009 07:38:06 +0000

I have not yet read through everything, but I find it absolutely incredible that you’ve tackled this aspect of JRuby in such a systematic way. I’ll try to post comments if anything needs correction, but my quick read tells me you’re totally on the right track, if not exactly correct. JRuby is actually a very simple implementation at its core, surrounded by a lot of complex tricks to make things fast. Hopefully we can bring those two goals together.