From: Jim Cain <list@...>
Date: 2003-07-04T16:13:08+09:00
Subject: Re: rb_gc_mark(): unknown data type...non object

Yukihiro Matsumoto wrote:

> Hi,
> 
> In message "rb_gc_mark(): unknown data type...non object"
>     on 03/07/04, Jim Cain <list@jimcain.us> writes:
> 
> |I figure I'm getting this because I've got a VALUE that's not a Ruby 
> |object. Has anyone figured out a good way to track down such a bug?
> 
> I use gdb.  If you're not using your own extension, show us the
> backtrace (output from gdb "where" command).  We may be able to help
> you.
> 
> 							matz.
> 
> 

Thanks; it's my Ruby9i extension. I've wasted two days on this and 
haven't found anything definitive. Even when I would explicitly start 
the gc, sometimes I would get the error and sometimes not. I began to 
suspect that it wasn't a bad VALUE but rather a buffer overrun elsewhere 
that was corrupting a VALUE.

In the meantime, I was reading some previous posts about rb_obj_alloc 
"only working for T_OBJECT classes" in 1.6.x. Just what exactly are 
T_OBJECT classes? Non-builtin classes? I wasn't sure just what was meant 
by that, and I do use rb_obj_alloc in a few cases, so out of curiosity I 
built my extension on 1.8, and now I don't get the gc "unknown data 
type" error. At least not yet. Maybe just a coincidence. We'll see.