From b62c197a226d08c24f3ecf95b3ff3cfaae0a0c0b Mon Sep 17 00:00:00 2001
From: wangjohn <wangjohn@mit.edu>
Date: Mon, 8 Apr 2013 16:50:05 -0400
Subject: [PATCH] Creating an object to consolidate thread locals which hold
 the instrumenters for the AS::Notifications module.

---
 .../lib/active_support/notifications.rb       | 28 ++++++++++++++++++-
 1 file changed, 27 insertions(+), 1 deletion(-)

diff --git a/activesupport/lib/active_support/notifications.rb b/activesupport/lib/active_support/notifications.rb
index 705a4693b7..ab2bb5fafe 100644
--- a/activesupport/lib/active_support/notifications.rb
+++ b/activesupport/lib/active_support/notifications.rb
@@ -177,7 +177,33 @@ module ActiveSupport
       end
 
       def instrumenter
-        Thread.current[:"instrumentation_#{notifier.object_id}"] ||= Instrumenter.new(notifier)
+        InstrumentationRegistry.instrumenter_for(notifier)
+      end
+    end
+
+    # This class is a registry which holds all of the +Instrumenter+ objects
+    # in a particular thread local. To access the +Instrumenter+ object for a
+    # particular +notifier+, you can call the following method:
+    #
+    #   InstrumentationRegistry.instrumenter_for(notifier)
+    #
+    # The instrumenters for multiple notifiers are held in a single instance of
+    # this class.
+    class InstrumentationRegistry # :nodoc:
+      class << self
+        delegate :instrumenter_for, to: :current
+
+        def current
+          Thread.current[:instrumentation_registry] ||= new
+        end
+      end
+
+      def initialize
+        @registry = {}
+      end
+
+      def instrumenter_for(notifier)
+        @registry[notifier] ||= Instrumenter.new(notifier)
       end
     end