From: Michael Neumann <mneumann@...>
Date: 2004-05-11T03:47:00+09:00
Subject: (fwd) [Borges-users] memory strikes back!

Can anyone of the Ruby experts tell us where the memory leak might be?

--- forwarded message ---
 
Hi,

about the ol' Borges memory problem: there's a small but nonzero 
possibility that continuations+objects+weakrefs are a bad combination 
in Ruby, after all. Here's a small test I just wrote. I let it grow to 
about 70 megs on my system before shutting it down... although it's 
obvious from the code that memory should be bounded.


require 'weakref'

class A
        attr_accessor :child

        def foo
                @child = B.new
                @child.call
        end
end

class B
        def call
                callcc do |cc|
                        @cont = cc
                end
        end

        def answer(obj)
                @cont.call(obj)
        end
end

def purge(array)
        array.delete_if {|x| not x.weakref_alive?}
end

a = A.new
arr = []
loop { a.foo; arr << WeakRef.new(a.child); purge(arr)}


Funny thing is: if we remove the weakref array thing, memory is 
bounded; and if we don't save the continuation, memory is bounded too. 
Maybe I'm mistaken somewhere. Actually I hope I'm mistaken. Somebody 
correct me.

Vladimir Slepnev