From: Joel VanderWerf <vjoel@...>
Date: 2002-06-17T06:08:20+09:00
Subject: debugging GC


Hi.
I've been debugging memory problems in a ruby app lately, and I needed
to know why certain objects were not collected. So I patched gc.c and
memory.c to add a method to the GC module that accepts an object and
returns an array of arrays, each of which represents a path from root
references (stack, globals, etc.) up to (but not including) your object.
It's fairly useful, but limited. Unfortunately, this functionality
cannot be easily implemented as an extension, only as a patch, because
hardcoded calls to rb_gc_mark are all over the place, and there is no
way to customize the behavior of rb_gc_mark. Anyway, it's at:

  http://redshift.sourceforge.net/debugging-GC/

Hope it's useful to someone besides me...