From: "evanwebb@..." <evanwebb@...>
Date: 2007-10-29T14:20:11+09:00
Subject: Re: JRuby disabling ObjectSpace: what implications?

On Oct 28, 9:19 am, Charles Oliver Nutter <charles.nut...@sun.com>
wrote:
<snip>
>
> ObjectSpace is just not compatible with any GC that requires the ability
> to move objects around in memory, run in parallel, and so on. It can
> *never* be deterministic unless it can "stop the world", so it should
> not be used for algorithms that require any level of determinism, such
> as the test search in test/unit.

This is the exact reason we haven't yet implemented each_object in
Rubinius yet.

Having a generational GC that moves objects, iterating over all
objects is very,
very non-deterministic unless the GC is totally turned off while
objects are walked.

Thats at least an option we have that we may roll with for the initial
release, but
it's less than ideal.

I think of each_object as very much a MRI implementation feature that
the rest of us
implementors struggle to implement. Because of this, the community and
core members of
each implementation need to really beginning discussing whether or not
each_object is a
Ruby feature or an MRI feature.

 - Evan