From: Markus <markus@...>
Date: 2004-10-25T23:27:31+09:00
Subject: Re: [BUG] Strange weak-ref behaviour

     I may be confused, but I do not see where you are even using using
weak-refs.  It looks like you are doing something like this:

      * 1000 times
              * Making an object
              * Noting its id
              * Setting it free to wander in the woods unreferenced
      * Sending the wolf into the woods to hunt unreferenced objects
      * Calling for it by id
      * Being surprised to hear that it is no longer with us

This does not look like a bug to me (I wouldn't expect them to answer
after I've set the wolf on them), but I may be misunderstanding.

-- Markus

On Sat, 2004-10-23 at 16:51, Michael Neumann wrote:
> Hi. Take a look at the source code at the end of the email and run it.
> The expected output for me is, either an empty string ("") or nothing
> (and this up to 1000 times).  But, the output I get (on both Ruby 1.8.x
> and 1.9) is like that shown below:
> 
>   "w.rb:16:in `_id2ref'"
>   ["w.rb:16:in `_id2ref'", "w.rb:16:in `each_object'", "w.rb:14:in
>   `each'", "/home/mneumann/usr/lib/ruby/1.9/set.rb:193:in `each_key'",
>   "/home/mneumann/usr/lib/ruby/1.9/set.rb:193:in `each'", "w.rb:14:in
>   `each_object'", "w.rb:30"]
>   "w.rb:16:in `_id2ref'"
>   "/home/mneumann/usr/lib/ruby/1.9/set.rb:193:in `each'"
>   "/home/mneumann/usr/lib/ruby/1.9/set.rb:193:in `each_key'"
>   "w.rb:14:in `each'"
>   #<RangeError: 0x4086550 is recycled object>
>   ["w.rb:16:in `_id2ref'", "w.rb:16:in `each_object'", "w.rb:14:in
>   `each'", "/home/mneumann/usr/lib/ruby/1.9/set.rb:193:in `each_key'",
>   "/home/mneumann/usr/lib/ruby/1.9/set.rb:193:in `each'", "w.rb:14:in
>   `each_object'", "w.rb:30"]
>   #<RangeError: 0x4084e1c is recycled object>
>   "w.rb:14:in `each'"
>   "w.rb:14:in `each_object'"
>   "w.rb:14:in `each'"
>   "w.rb:16:in `_id2ref'"
>   "w.rb:14:in `each_object'"
>   "w.rb:30"
> 
> There must be something wrong, or is this correct? Does Ruby reuse
> object_id's? BTW, what happens if an application uses more than 4 billon
> (32-bit) objects? Does Ruby fail or reuse old object_ids?
> 
> Thanks in advance.
> 
> Regards,
> 
>   Michael
> 
> 
> #################################
> # here the code. if no output is shown, try to 
> # increase the number of objects registered (1000) 
> #
>   require 'set'
> 
>   class StateRegistry
> 
>     def initialize
>       @registered_objects = Set.new
>     end
> 
>     def register(obj)
>       @registered_objects.add(obj.object_id)
>     end
> 
>     def each_object 
>       @registered_objects.each do |oid|
>         begin
>           obj = ObjectSpace._id2ref(oid) 
>         rescue RangeError
>           next
>         end
>         yield obj
>       end
>     end
>   end
> 
>   s = StateRegistry.new
>   1000.times do 
>     s.register("")
>   end
>   ObjectSpace.garbage_collect
>   s.each_object {|obj| p obj}