From: Simon Strandgaard <0bz63fz3m1qt3001@...>
Date: 2003-04-17T20:21:45+09:00
Subject: Re: tutorial on embedding ruby (review)

On Wed, 16 Apr 2003 18:28:03 +0000, Steve Hart wrote:
> 
> Thanks v much for reply. However, Mauricio (prev reply) says v
> definitly gets GC'd whilst you say it may not - which is correct?. 

I don't know.. but I would think it gets destroyed by GC.



OK I think I know where you are going. 
You want an Abstract Factory which you can create ruby insances through ?

This reminds me of
http://rubyxx.sourceforge.jp/index.en.html

I have made some modifications for your code :-)


class ObjNode {
private:
    VALUE obj;
public:
    ObjNode(string name, VALUE value) : name(name), value(value) {
#ifdef USE_MARK
    }
    void Mark() {
        rb_gc_mark(obj);
    }
#else
        rb_gc_register_address(&obj);
    }
    ~ObjNode() {
        rb_gc_unregister_address(&obj);
    }
#endif
};

Observe that there is a "USE_MARK" define.. I don't know enough about
your situation, but this depends on where you hold the instance of
MyCPBaseClass. 
(a) If you instantiate it from ruby then  define USE_MARK.
(b) If you instantiate it from c++  then  UNdefine USE_MARK.

You can see an example of the (a) situation if you look here: 
http://metaeditor.sourceforge.net/embed/mark.png


This concept is not easy to grasp... but its about wheter
your MyCPPBaseClass is memory managed from ruby(a) or cpp(b).
Who is the parants-parent?  (grand-parent)


OK.. I will take a break now and have some breakfast :-)
--
Simon Strandgaard