Prefer weakrefs to ObjectSpace for tracking created queues for shutdown,

to make JRuby happy.  Breaks on rbx.

lib/girl_friday.rb

@@ -1,4 +1,5 @@
 require 'thread'
+require 'weakref'
 begin
   # Rubinius
   require 'actor'
@@ -15,8 +16,13 @@
 
 module GirlFriday
 
+  @@queues = []
+  def self.queues
+    @@queues
+  end
+
   def self.status
-    ObjectSpace.each_object(WorkQueue).inject({}) { |memo, queue| memo.merge(queue.status) }
+    queues.delete_if { |q| !q.weakref_alive? }.inject({}) { |memo, queue| queue.weakref_alive? ? memo.merge(queue.status) : memo }
   end
 
   ##
@@ -27,14 +33,16 @@ def self.status
   #
   # Note that shutdown! just works with existing queues.  If you create a
   # new queue, it will act as normal.
+  #
+  # WeakRefs make this method full of race conditions with GC. :-(
   def self.shutdown!(timeout=30)
-    queues = []
-    ObjectSpace.each_object(WorkQueue).each { |q| queues << q }
+    queues.delete_if { |q| !q.weakref_alive? }
     count = queues.size
-    m = Mutex.new
-    var = ConditionVariable.new
 
     if count > 0
+      m = Mutex.new
+      var = ConditionVariable.new
+
       queues.each do |q|
         q.shutdown do |queue|
           m.synchronize do

lib/girl_friday/work_queue.rb

@@ -5,6 +5,7 @@ class WorkQueue
     Work = Struct.new(:msg, :callback)
     Shutdown = Struct.new(:callback)
 
+
     attr_reader :name
     def initialize(name, options={}, &block)
       @name = name.to_s
@@ -18,6 +19,7 @@ def initialize(name, options={}, &block)
       @total_processed = @total_errors = @total_queued = 0
       @persister = (options[:store] || Store::InMemory).new(name, (options[:store_config] || []))
       start
+      GirlFriday.queues << WeakRef.new(self)
     end
 
     def push(work, &block)

test/test_girl_friday.rb

@@ -128,7 +128,8 @@ def test_should_allow_graceful_shutdown
         queue.push(:text => 'foo')
       end
 
-      GirlFriday.shutdown!
+      count = GirlFriday.shutdown!
+      assert_equal 0, count
       s = queue.status
       assert_equal 0, s['shutdown'][:busy]
       assert_equal 2, s['shutdown'][:ready]