From: ts <decoux@...>
Date: 2001-12-29T00:08:24+09:00
Subject: [ruby-talk:29533] Re: GC and values in extensions

>>>>> "P" == Paul Brannan <paul@atdesk.com> writes:

P>   VALUE foo(VALUE self) {
P>     VALUE x = rb_str_new2("foo");
P>     long y = (long)x; /* Assume x and y now have the same bit pattern */
P>     x = Qnil;
P>     ...
P>     return Qnil;
P>   }

 Well a better example is

   VALUE tt(self)
      VALUE self;
   {
      VALUE x = rb_str_new2("foo");
      return rb_funcall(self, rb_intern("uu"), 1, x);
   }

   rb_funcall() can call rb_gc(), if x is not marked you can have
   problems. 

P> This also sounds a little inefficient to me (though it makes things
P> convenient for extension writers).  Is it?

 Your example is a little pathological :-)) but it make thing very
 convenient for extension writers (and also for ruby). It's really pleasant
 to write extension in ruby unlike in other P languages (where you must
 manage a reference count or something like this)


Guy Decoux