From: Joel VanderWerf <vjoel@...>
Date: 2005-08-12T04:25:35+09:00
Subject: Re: force_recycle

Kroeger Simon (ext) wrote:
> Hi Nobu,
> 
> i realy appreciate your input but that's not the kind of problem 
> I'm facing (and I probably should have elaborated the issue 
> further when asking such questions).
> At one point in our project a large number of plain ruby objects
> gets alocated (no relation to external resources) and stored in
> an array (all of the same class). This happens from various Threads 
> but in a (hopefully) threadsafe manner. Later this array gets 
> #clear(ed). After GC there are still instances of the class in the
> ObjectSpace even though this special class is only used for 
> elements of this array. This process repeats itself over and
> over again and after some hours we have hundreds of MB memory
> leak.
> 
> So, what I'm realy looking for is a way to ask: 'hey almighty 
> shepherd of objects, why are you still clinging to xyz?'

I patched the ruby interpreter to divulge this information, but that was
back at 1.6 and 1.7, so it would probably need some work for 1.8.

If you're interested, there's a mention of the patch at

http://www.rubygarden.org/ruby?GCAndMemoryManagement

and the patch itself is at

http://www.google.com/url?sa=D&q=http%3A%2F%2Fredshift.sourceforge.net%2Fdebugging-GC%2F

Briefly, the patch adds a method

GC.reachability_paths obj

which returns a list of all the ways you can reference that object,
starting from the basic references such as C and ruby globals, stack
variables, and others.

-- 
      vjoel : Joel VanderWerf : path berkeley edu : 510 665 3407