1 files changed, 61 insertions, 0 deletions
diff --git a/activesupport/lib/active_support/notifications/instrumenter.rb b/activesupport/lib/active_support/notifications/instrumenter.rb
index e99f5ee688..f8344912bb 100644
--- a/activesupport/lib/active_support/notifications/instrumenter.rb
+++ b/activesupport/lib/active_support/notifications/instrumenter.rb
@@ -63,6 +63,42 @@ module ActiveSupport
         @end            = ending
         @children       = []
         @duration       = nil
+        @cpu_time_start = nil
+        @cpu_time_finish = nil
+        @allocation_count_start = 0
+        @allocation_count_finish = 0
+      end
+
+      # Record information at the time this event starts
+      def start!
+        @time = now
+        @cpu_time_start = now_cpu
+        @allocation_count_start = now_allocations
+      end
+
+      # Record information at the time this event finishes
+      def finish!
+        @cpu_time_finish = now_cpu
+        @end = now
+        @allocation_count_finish = now_allocations
+      end
+
+      # Returns the CPU time (in milliseconds) passed since the call to
+      # +start!+ and the call to +finish!+
+      def cpu_time
+        (@cpu_time_finish - @cpu_time_start) * 1000
+      end
+
+      # Returns the idle time time (in milliseconds) passed since the call to
+      # +start!+ and the call to +finish!+
+      def idle_time
+        duration - cpu_time
+      end
+
+      # Returns the number of allocations made since the call to +start!+ and
+      # the call to +finish!+
+      def allocations
+        @allocation_count_finish - @allocation_count_start
       end
 
       # Returns the difference in milliseconds between when the execution of the
@@ -88,6 +124,31 @@ module ActiveSupport
       def parent_of?(event)
         @children.include? event
       end
+
+      private
+        def now
+          Process.clock_gettime(Process::CLOCK_MONOTONIC)
+        end
+
+        if defined?(Process::CLOCK_PROCESS_CPUTIME_ID)
+          def now_cpu
+            Process.clock_gettime(Process::CLOCK_PROCESS_CPUTIME_ID)
+          end
+        else
+          def now_cpu
+            0
+          end
+        end
+
+        if defined?(JRUBY_VERSION)
+          def now_allocations
+            0
+          end
+        else
+          def now_allocations
+            GC.stat :total_allocated_objects
+          end
+        end
     end
   end
 end