From: "ara.t.howard" <ara.t.howard@...>
Date: 2007-09-26T01:49:32+09:00
Subject: Re: ObjectSpace.define_finalizer and memory leaks


On Sep 25, 2007, at 10:14 AM, Sylvain Joyeux wrote:

>> it seems like you should be able to define a finalizer on any object
>> without preventing it from being gc'd!
> The only way I am aware of is to use methods ...
> ObjectSpace.define_finalizer(obj, &method(:my_finalizer))
> --  
> Sylvain Joyeux                              http://www.laas.fr/ 
> ~sjoyeux

working off of you idea of avoiding any new references whatsoever i  
came up with this, which is working for me, can others confirm?

cfp:~ > cat a.rb
class C
   def self.count
     c = 0
     ObjectSpace.each_object do |object|
       c += 1 if self === object rescue next
     end
     c
   end
end

def finalizer_for object_id
   lambda { p [:finalized, object_id] if $DEBUG }
end

loop do
   (2 ** 16).times do
     c = C.new
     finalizer = finalizer_for c.object_id
     c.instance_eval do
       ObjectSpace.define_finalizer self, &finalizer
     end
   end

   puts "before: #{ C.count }"

   GC.start

   puts "after: #{ C.count }"
   puts
end


thanks for the inspiration!

kind regards.

a @ http://drawohara.com/
--
we can deny everything, except that we have the possibility of being  
better. simply reflect on that.
h.h. the 14th dalai lama