1 files changed, 33 insertions, 12 deletions
diff --git a/activesupport/lib/active_support/notifications.rb b/activesupport/lib/active_support/notifications.rb
index 099117cebb..b32aa75e59 100644
--- a/activesupport/lib/active_support/notifications.rb
+++ b/activesupport/lib/active_support/notifications.rb
@@ -1,5 +1,6 @@
 require 'active_support/notifications/instrumenter'
 require 'active_support/notifications/fanout'
+require 'active_support/per_thread_registry'
 
 module ActiveSupport
   # = Notifications
@@ -84,15 +85,15 @@ module ActiveSupport
   # resulting in the following output within the logs including a hash with the payload:
   #
   #   notification: process_action.action_controller 2012-04-13 01:08:35 +0300 2012-04-13 01:08:35 +0300 af358ed7fab884532ec7 {
-  #      :controller=>"Devise::SessionsController",
-  #      :action=>"new",
-  #      :params=>{"action"=>"new", "controller"=>"devise/sessions"},
-  #      :format=>:html,
-  #      :method=>"GET",
-  #      :path=>"/login/sign_in",
-  #      :status=>200,
-  #      :view_runtime=>279.3080806732178,
-  #      :db_runtime=>40.053
+  #      controller: "Devise::SessionsController",
+  #      action: "new",
+  #      params: {"action"=>"new", "controller"=>"devise/sessions"},
+  #      format: :html,
+  #      method: "GET",
+  #      path: "/login/sign_in",
+  #      status: 200,
+  #      view_runtime: 279.3080806732178,
+  #      db_runtime: 40.053
   #    }
   #
   # You can also subscribe to all events whose name matches a certain regexp:
@@ -142,8 +143,8 @@ module ActiveSupport
   #
   # == Default Queue
   #
-  # Notifications ships with a queue implementation that consumes and publish events
-  # to log subscribers in a thread. You can use any queue implementation you want.
+  # Notifications ships with a queue implementation that consumes and publishes events
+  # to all log subscribers. You can use any queue implementation you want.
   #
   module Notifications
     class << self
@@ -177,7 +178,27 @@ 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:
+      extend ActiveSupport::PerThreadRegistry
+
+      def initialize
+        @registry = {}
+      end
+
+      def instrumenter_for(notifier)
+        @registry[notifier] ||= Instrumenter.new(notifier)
       end
     end