1 files changed, 10 insertions, 7 deletions
diff --git a/actionpack/lib/action_dispatch/middleware/callbacks.rb b/actionpack/lib/action_dispatch/middleware/callbacks.rb
index 49bc20f11f..8098933e01 100644
--- a/actionpack/lib/action_dispatch/middleware/callbacks.rb
+++ b/actionpack/lib/action_dispatch/middleware/callbacks.rb
@@ -1,4 +1,10 @@
 module ActionDispatch
+  # Provide callbacks to be executed before and after the request dispatch.
+  #
+  # It also provides a to_prepare callback, which is performed in all requests
+  # in development by only once in production and notification callback for async
+  # operations.
+  #
   class Callbacks
     include ActiveSupport::Callbacks
 
@@ -29,12 +35,6 @@ module ActionDispatch
       set_callback(:call, :after, *args, &block)
     end
 
-    class << self
-      # DEPRECATED
-      alias_method :before_dispatch, :before
-      alias_method :after_dispatch, :after
-    end
-
     def initialize(app, prepare_each_request = false)
       @app, @prepare_each_request = app, prepare_each_request
       run_callbacks(:prepare)
@@ -43,7 +43,10 @@ module ActionDispatch
     def call(env)
       run_callbacks(:call) do
         run_callbacks(:prepare) if @prepare_each_request
-        @app.call(env)
+
+        ActiveSupport::Notifications.instrument "action_dispatch.callback" do
+          @app.call(env)
+        end
       end
     end
   end