From 7deeb9c1b608101b3ce04792aaeac1726bddcdbe Mon Sep 17 00:00:00 2001
From: Evan Phoenix <evan@fallingsnow.net>
Date: Fri, 24 Jun 2011 09:52:47 -0700
Subject: [PATCH] Eliminate usage of ObjectSpace._id2ref

Two reasons not to use _id2ref:
1) It's slow on other ruby implementations
2) It introduces a hidden bug because _id2ref can return any random
   future object since object ids are recycled
---
 lib/rr/injections/double_injection.rb         | 15 +++++++++++----
 lib/rr/injections/method_missing_injection.rb |  9 +++++++--
 2 files changed, 18 insertions(+), 6 deletions(-)

diff --git a/lib/rr/injections/double_injection.rb b/lib/rr/injections/double_injection.rb
index 3c106c87..0ce4e13e 100644
--- a/lib/rr/injections/double_injection.rb
+++ b/lib/rr/injections/double_injection.rb
@@ -119,11 +119,15 @@ def bind
         self
       end
 
+      BoundObjects = {}
+
       def bind_method_that_self_destructs_and_delegates_to_method_missing
-        subject_class_object_id = subject_class.object_id
+        id = BoundObjects.size
+        BoundObjects[id] = subject_class
+
         subject_class.class_eval(<<-RUBY, __FILE__, __LINE__ + 1)
         def #{method_name}(*args, &block)
-          ObjectSpace._id2ref(#{subject_class_object_id}).class_eval do
+          ::RR::Injections::DoubleInjection::BoundObjects[#{id}].class_eval do
             remove_method(:#{method_name})
           end
           method_missing(:#{method_name}, *args, &block)
@@ -133,11 +137,14 @@ def #{method_name}(*args, &block)
       end
 
       def bind_method
-        subject_class_object_id = subject_class.object_id
+        id = BoundObjects.size
+        BoundObjects[id] = subject_class
+
         subject_class.class_eval(<<-RUBY, __FILE__, __LINE__ + 1)
         def #{method_name}(*args, &block)
           arguments = MethodArguments.new(args, block)
-          RR::Injections::DoubleInjection.dispatch_method(self, ObjectSpace._id2ref(#{subject_class_object_id}), :#{method_name}, arguments.arguments, arguments.block)
+          obj = ::RR::Injections::DoubleInjection::BoundObjects[#{id}]
+          RR::Injections::DoubleInjection.dispatch_method(self, obj, :#{method_name}, arguments.arguments, arguments.block)
         end
         RUBY
         self
diff --git a/lib/rr/injections/method_missing_injection.rb b/lib/rr/injections/method_missing_injection.rb
index d8f27428..d0421fb9 100644
--- a/lib/rr/injections/method_missing_injection.rb
+++ b/lib/rr/injections/method_missing_injection.rb
@@ -51,11 +51,16 @@ def reset
       end
 
       protected
+      BoundObjects = {}
+
       def bind_method
-        subject_class_object_id = subject_class.object_id
+        id = BoundObjects.size
+        BoundObjects[id] = subject_class
+
         subject_class.class_eval((<<-METHOD), __FILE__, __LINE__ + 1)
         def method_missing(method_name, *args, &block)
-          MethodDispatches::MethodMissingDispatch.new(self, ObjectSpace._id2ref(#{subject_class_object_id}), method_name, args, block).call
+          obj = ::RR::Injections::MethodMissingInjection::BoundObjects[#{id}]
+          MethodDispatches::MethodMissingDispatch.new(self, obj, method_name, args, block).call
         end
         METHOD
       end