From: Charles Oliver Nutter <charles.nutter@...>
Date: 2007-10-29T02:13:30+09:00
Subject: Re: JRuby disabling ObjectSpace: what implications?

Ken Bloom wrote:
> I don't think they're making ObjectSpace go away. Just 
> ObjectSpace#each_object.

Correct.

> On Sun, 28 Oct 2007 22:13:38 +0900, Daniel Berger wrote:
>> drb: This could be a big deal.
>> weakref: You've stated that Java has its own implementation.
> 
> This uses _id2ref, which doesn't appear to be going away.

Not that I wouldn't like it to :)

>> cgi: This could be a problem. Then again, some people say this library
>> should be refactored or tossed.
>> finalize: Did anyone even know about this? Does anyone use it?
>> tempfile: Meh, I'm guessing Java has its own library for temp files. I
>> never liked the current implementation anyway (which is why I wrote
>> file-temp).
> 
> Finalizers could be implemented using Java's finalize() method for 
> classes that need it. This method of implementing finalizers could 
> probably be compatibly exposed using ObjectSpace.

Correct; we do support finalizers already. They weren't actually that 
hard to support, since as you say Java already supports finalization.

>> shell: This could be a problem.
> 
> This looks broken anyway since it uses fork.

Ahh yes, fork is a killer. We will never, ever support fork.

>> singleton: Ditto.
> 
> one is in documentation comment, giving an example of a specific behavior 
> of the library. the other is in the same example, included executably 
> after an if __FILE__ == $0 condition. So no actual problem here.

Whew, that's good to hear. I know singleton is used a bit in Rails, and 
most people run JRuby on Rails with ObjectSpace disabled...so this seems 
to fit with your findings.

>> irb: You've got jirb.
> 
> jirb is (at its core) still the Ruby 1.8 IRB codebase. The example you 
> pointed ou is class (Module) iteration, used for completion, but it's 
> more general iteration than test/unit uses, and #inherited techniques 
> that can be used for test/unit may not work here.

inherited, perhaps not. But a JRuby-internal weak list of Module 
instances would put this one to rest.

- Charlie