From df058ea0e3e13ad52fd3a3490b1e3bd56db044b2 Mon Sep 17 00:00:00 2001
From: nobu <nobu@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
Date: Tue, 13 Mar 2012 03:37:06 +0000
Subject: Bug #5350 * gc.c: add ObjectSpace::WeakMap.  [ruby-dev:44565][Bug
 #5350] * lib/weakref.rb: use WeakMap instead of _id2ref.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@34995 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
---
 lib/weakref.rb | 48 ++++++++++--------------------------------------
 1 file changed, 10 insertions(+), 38 deletions(-)

(limited to 'lib/weakref.rb')

diff --git a/lib/weakref.rb b/lib/weakref.rb
index ee5444a584..78f88a3f12 100644
--- a/lib/weakref.rb
+++ b/lib/weakref.rb
@@ -1,5 +1,4 @@
 require "delegate"
-require 'thread'
 
 # Weak Reference class that allows a referenced object to be
 # garbage-collected.  A WeakRef may be used exactly like the object it
@@ -24,51 +23,24 @@ class WeakRef < Delegator
   class RefError < StandardError
   end
 
-  @@id_map =  {}                # obj -> [ref,...]
-  @@id_rev_map =  {}            # ref -> obj
-  @@mutex = Mutex.new
-  @@final = lambda {|id|
-    @@mutex.synchronize {
-      rids = @@id_map[id]
-      if rids
-        for rid in rids
-          @@id_rev_map.delete(rid)
-        end
-        @@id_map.delete(id)
-      end
-      rid = @@id_rev_map[id]
-      if rid
-        @@id_rev_map.delete(id)
-        @@id_map[rid].delete(id)
-        @@id_map.delete(rid) if @@id_map[rid].empty?
-      end
-    }
-  }
+  @@__map = ::ObjectSpace::WeakMap.new
 
   ##
   # Creates a weak reference to +orig+
 
   def initialize(orig)
-    @__id = orig.object_id
-    ObjectSpace.define_finalizer orig, @@final
-    ObjectSpace.define_finalizer self, @@final
-    @@mutex.synchronize {
-      @@id_map[@__id] = [] unless @@id_map[@__id]
-    }
-    @@id_map[@__id].push self.object_id
-    @@id_rev_map[self.object_id] = @__id
+    case orig
+    when true, false, nil
+      @delegate_sd_obj = orig
+    else
+      @@__map[self] = orig
+    end
     super
   end
 
   def __getobj__ # :nodoc:
-    unless @@id_rev_map[self.object_id] == @__id
-      Kernel::raise RefError, "Invalid Reference - probably recycled", Kernel::caller(2)
-    end
-    begin
-      ObjectSpace._id2ref(@__id)
-    rescue RangeError
-      Kernel::raise RefError, "Invalid Reference - probably recycled", Kernel::caller(2)
-    end
+    @@__map[self] or defined?(@delegate_sd_obj) ? @delegate_sd_obj :
+      Kernel::raise(RefError, "Invalid Reference - probably recycled", Kernel::caller(2))
   end
 
   def __setobj__(obj) # :nodoc:
@@ -78,7 +50,7 @@ class WeakRef < Delegator
   # Returns true if the referenced object is still alive.
 
   def weakref_alive?
-    @@id_rev_map[self.object_id] == @__id
+    !!(@@__map[self] or defined?(@delegate_sd_obj))
   end
 end
 
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