From: matz@... (Yukihiro Matsumoto)
Date: 2001-06-14T01:34:24+09:00
Subject: [ruby-talk:16460] Re: C extension questions

Hi,

In message "[ruby-talk:16458] C extension questions"
    on 01/06/13, Christian Szegedy <szegedy@or.uni-bonn.de> writes:

|Is the only task of the mark function, I pass over to 
|the Data_Wrap_Structure, to call rb_gc_mark for all
|elements held by the data structure?

Basically yes.  Even though you can do something else, I strongly
recommend you to avoid calling ruby functions, since it may try
allocating objects, but during GC mark phase, memory is starving by
definition.

|Is it possible to pass over multiple arguments to the 
|block using rb_yield or is there some similarly simple
|method for this?

invoke rb_yield() with array argument, for example,

  rb_yield(rb_ary_new3(3, INT2FIX(1), INT2FIX(2), INT2FIX(3)));

|Can I relay on using FL_USER* (in ruby.h) flags
|for my own objects?
|(Are they guarateed to exist in future versions...)

I think so.  It's hard to guarantee something, I'll try.

							matz.