From: Rick DeNatale <rick.denatale@...>
Date: 2006-10-27T00:38:05+09:00
Subject: Re: debugging memory use and GC

On 10/25/06, snacktime <snacktime@gmail.com> wrote:
> What is a good way to find out what objects are not being GC'd ?  I am
> seeing a strange pattern I can't figure out.  The app is handling
> large files and will use up to 150mb or so of memory and then when I
> call GC.start it goes back down to around 8mb.  But after a few cycles
> memory stops being reclaimed.

Of course, what you really want to know is not just what's not getting
GCed but WHY.

This can be a difficult problem.  You really want to find the
reference paths from root objects.

Some GC languages like Smalltalk have methods in object to get a list
of everything which references it. I haven't seen such a facility in
Ruby.  Then the problem with this is that calling this method
generates additional references to the objects referencing the object
etc.  This kind of heisenberg effect makes building a tool to find
reference paths difficult.

-- 
Rick DeNatale

My blog on Ruby
http://talklikeaduck.denhaven2.com/