update resque instrumentation to use a plugin for most of the work

README.md

@@ -48,6 +48,13 @@ Both MongoMapper and Mongoid are supported.  You can disable them both by settin
 
 ### Resque
 
+Make sure that your jobs either inherit from Resque::Job or else include our instrumentation:
+
+class MyJob
+  require 'rpm_contrib/instrumentation/resque'
+  include Resque::Plugins::NewRelicInstrumentation
+end
+
 To disable resque, set 'disable_resque' to true in your newrelic.yml file.
 
 ### Redis

lib/rpm_contrib/instrumentation/resque.rb

@@ -1,61 +1,32 @@
-
-module RPMContrib
-  SUPPORTS_FORK =
-    begin
-      # jruby has a Kernel.fork method, but it raises NotImplementedError by default
-      if Kernel.respond_to?(:fork)
-        Kernel.fork { exit! }
-        true
-      else
-        false
+module Resque
+  module Plugins
+    module NewRelicInstrumentation
+      include NewRelic::Agent::Instrumentation::ControllerInstrumentation
+
+      def around_perform_with_monitoring(*args)
+        perform_action_with_newrelic_trace(:name => 'perform', :class_name => class_name, :category => 'OtherTransaction/ResqueJob') do
+          yield(*args)
+        end
       end
-    rescue NotImplementedError
-      false
     end
+  end
+end
 
+module RPMContrib
   module Instrumentation
-    # == Resque Instrumentation
-    #
-    # Installs a hook to ensure the agent starts manually when the worker
-    # starts and also adds the tracer to the process method which executes
-    # in the forked task.
     module Resque
-      def self.flush_metric_data
-        return if !NewRelic::Agent.agent.started? || NewRelic::Agent.agent.instance_variable_get(:@worker_loop).nil?
-        NewRelic::Agent.agent.instance_variable_get(:@worker_loop).run_task
+      ::Resque.before_first_fork do
+        NewRelic::Agent.manual_start(:dispatcher => :resque)
       end
 
-      ::Resque::Job.class_eval do
-        include NewRelic::Agent::Instrumentation::ControllerInstrumentation
-
-        old_perform_method = instance_method(:perform)
-
-        define_method(:perform) do
-          class_name = (payload_class ||self.class).name
-          NewRelic::Agent.reset_stats if NewRelic::Agent.respond_to? :reset_stats
-          perform_action_with_newrelic_trace(:name => 'perform', :class_name => class_name,
-                                             :category => 'OtherTransaction/ResqueJob') do
-            old_perform_method.bind(self).call
-          end
-
-          if ::RPMContrib::SUPPORTS_FORK
-            NewRelic::Agent.shutdown unless defined?(::Resque.before_child_exit)
-          else
-            ::RPMContrib::Instrumentation::ResqueInstrumentation.flush_metric_data unless defined?(::Resque.before_child_exit)
-          end
-
-        end
+      ::Resque.after_fork do
+        NewRelic::Agent.after_fork(:force_reconnect => false)
       end
 
-      if defined?(::Resque.before_child_exit)
-        ::Resque.before_child_exit do |worker|
-          if ::RPMContrib::SUPPORTS_FORK
-            NewRelic::Agent.shutdown
-          else
-            ::RPMContrib::Instrumentation::ResqueInstrumentation.flush_metric_data
-          end
-        end
+      ::Resque::Job.class_eval do
+        include Resque::Plugins::NewRelicInstrumentation
       end
     end
   end
-end if defined?(::Resque::Job) and not NewRelic::Control.instance['disable_resque']
+end if defined?(::Resque) and not NewRelic::Control.instance['disable_resque']
+