From: Yohanes Santoso <ysantoso-rubytalk@...>
Date: 2006-07-07T09:14:42+09:00
Subject: Re: GC oddness

Alex Young <alex@blackkettle.org> writes:

> nobu@ruby-lang.org wrote:
>> Hi,
>> At Thu, 6 Jul 2006 23:58:27 +0900,
>> Alex Young wrote in [ruby-talk:200382]:
>>
>>> Can someone smarter tell me why this fails?  I'm expecting the
>>> TestDir to get GC'd when I call GC.start in the test, but
>>> something's obviously keeping a reference lying around.  I just
>>> can't see what it is...
>> The finalizer proc refers testdir.
> I thought it might be that, but this also fails:

It does not fail on me:

require 'test/unit'
require 'fileutils'

class TestDir
   @@dir = nil
   @@clearup = proc {|id| FileUtils.rm_rf(@@dir); puts "Cleaned"}

   def TestDir.set_finalizer(testdir, dir)
     @@dir = dir
     ObjectSpace.define_finalizer(testdir, @@clearup)
   end
   def initialize(dir)
     FileUtils.mkdir(dir)
     TestDir.set_finalizer(self, dir)
   end
end

class DestroyTest < Test::Unit::TestCase
   def test_destroy
     a = TestDir.new('test_dir')
     a = nil
     GC.start
     puts "GC invoked"
     assert !File.directory?('test_dir')
     puts "Done"
   end
end


$ ruby ./gc.rb
Loaded suite ./gc
Started
Cleaned
GC invoked
Done
.
Finished in 0.015623 seconds.

1 tests, 1 assertions, 0 failures, 0 errors


$ ruby -v
ruby 1.8.4 (2005-12-24) [i386-linux]

Which OS and ruby are you using?

YS.