From: ara howard <ara.t.howard@...>
Date: 2008-01-09T14:20:24+09:00
Subject: Re: why does this code leak?


On Jan 8, 2008, at 8:45 PM, Jan Dvorak wrote:

> It does not leak, objects are just not immediately released by the  
> GC. Try it
> running 1000 times (on local server preferably).

as i already posted - i posted the wrong code.  here is an even more  
distilled version:

cfp2:~ > cat a.rb
#
# distilled behaviour from dike.rb
#
   class Class
     Finalizer = lambda {}

     def leak_free_finalizer
       Finalizer
     end

     def leaky_finalizer
       lambda{}
     end

     def finalizer
       %r/leak/ =~ ARGV.first ? leaky_finalizer : leak_free_finalizer
     end

     def new *a, &b
       object = allocate
       object.send :initialize, *a, &b
       object
     ensure
       ObjectSpace.define_finalizer object, finalizer
     end
   end


#
# the above makes this code leak iff ARGV has "leak" in it
#
   require "yaml"

   7.times {
     GC.start

     y Array.name => ObjectSpace.each_object(Array){}

     Array.new
   }



cfp2:~ > ruby a.rb
---
Array: 21
---
Array: 49
---
Array: 58
---
Array: 58
---
Array: 58
---
Array: 58
---
Array: 58


cfp2:~ > ruby a.rb leak
---
Array: 21
---
Array: 38
---
Array: 54
---
Array: 67
---
Array: 79
---
Array: 91
---
Array: 103



so.... why does installing a static finalizer work ok, but a dynamic  
one leaks memory!?

i'm nice and confused now.


a @ http://codeforpeople.com/
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