action_view.rb in ddtrace-0.12.0.rc1

- old
+ new

@@ -3,12 +3,16 @@
 module Datadog
   module Contrib
     module Rails
       # Code used to create and handle 'rails.render_template' and 'rails.render_partial' spans.
       module ActionView
+        include Datadog::Patcher
+
         def self.instrument
           # patch Rails core components
-          Datadog::RailsRendererPatcher.patch_renderer
+          do_once(:instrument) do
+            Datadog::RailsRendererPatcher.patch_renderer
+          end
         end
 
         def self.start_render_template(payload)
           # retrieve the tracing context
           tracing_context = payload.fetch(:tracing_context)