From: William Djaja Tjokroaminata <billtj@...>
Date: 2002-08-24T04:59:15+09:00
Subject: Re: Why Ruby Uses Mark-and-Sweep GC?

Hi,

Probably I should ask this question instead, to people who are really
familiar with the internals of Ruby object and Ruby gc:

Will it be tricky to try to separate Ruby objects that will be involved in
the mark-and-sweep and those that won't (from C)?

For example, the simple function "rb_global_variable" registers the VALUE
address that will be marked (and therefore will not be swept).  Is it
possible to create a perfectly valid Ruby object (VALUE) that will not be
swept?  In other words, the Ruby gc will not be aware of the existence of
such objects.

From theoretical point of view, a Ruby object (VALUE) is just a model of
an object.  How it is gc'ed should be independent from this model.  But by
just scanning functions such as "rb_newobj", it is unclear whether we can
modify VALUE so that it will not participate in the sweep phase.  Probably
there are higher-order effects that will make simple tweaking impossible?

Regards,

Bill