From: ts <decoux@...>
Date: 2004-07-30T23:56:41+09:00
Subject: Re: C ext: GC claiming objects early

>>>>> "T" == Tilman Sauerbeck <tilman@code-monkey.de> writes:

T> 	rb_obj_call_init (rbres->self, 0, NULL);

 this is, no ?

        rb_obj_call_init(self, 0, NULL);

T> static VALUE c_notifier_set (VALUE self)

 Well, you attach a notifier to an object but with the construct

   o.some_meth.notifier do |r|
      do_stuff_with(r)
   end

 this object is never stored in a variable, this is why ruby remove it

 Normally you must write it

   res = o.some_method
   res.notifier do |r|
      do_stuff_with(r)
   end

 and it will work, until ruby call the GC for `res'

 If you want to make it work like it is actually, you must store the result
 of `o.some_method' in an Array defined in `o' when #notifier is called,
 and mark this array. It will be marked when ruby will mark `o'

 Now the problem is here

T> I _do_ want the GC to claim the object eventually, but not if the
T> callback might still be called.

 How do you know that the callback might still be called ?

 Because if you use a method to release a notifier, then you just need an
 Array (defined with rb_global_variable()) which store the object when
 #notifier is called and remove it when you release the notifier


Guy Decoux