Use Process.clock_gettime unit argument to save some floating point multiplications

Author: byroot

activerecord/lib/active_record/future_result.rb

@@ -102,12 +102,12 @@ def canceled?
 
       def execute_or_wait
         if pending?
-          start = Process.clock_gettime(Process::CLOCK_MONOTONIC)
+          start = Process.clock_gettime(Process::CLOCK_MONOTONIC, :float_millisecond)
           @mutex.synchronize do
             if pending?
               execute_query(@pool.connection)
             else
-              @lock_wait = (Process.clock_gettime(Process::CLOCK_MONOTONIC) - start) * 1_000
+              @lock_wait = (Process.clock_gettime(Process::CLOCK_MONOTONIC, :float_millisecond) - start)
             end
           end
         else

activesupport/lib/active_support/notifications/instrumenter.rb

@@ -62,12 +62,12 @@ class Event
       def initialize(name, start, ending, transaction_id, payload)
         @name           = name
         @payload        = payload.dup
-        @time           = start
+        @time           = start ? start.to_f * 1_000.0 : start
         @transaction_id = transaction_id
-        @end            = ending
+        @end            = ending ? ending.to_f * 1_000.0 : ending
         @children       = []
-        @cpu_time_start = 0
-        @cpu_time_finish = 0
+        @cpu_time_start = 0.0
+        @cpu_time_finish = 0.0
         @allocation_count_start = 0
         @allocation_count_finish = 0
       end
@@ -102,7 +102,7 @@ def finish!
       # 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
+        @cpu_time_finish - @cpu_time_start
       end
 
       # Returns the idle time time (in milliseconds) passed since the call to
@@ -130,7 +130,7 @@ def allocations
       #
       #   @event.duration # => 1000.138
       def duration
-        1000.0 * (self.end - time)
+        self.end - time
       end
 
       def <<(event)
@@ -143,18 +143,18 @@ def parent_of?(event)
 
       private
         def now
-          Process.clock_gettime(Process::CLOCK_MONOTONIC)
+          Process.clock_gettime(Process::CLOCK_MONOTONIC, :float_millisecond)
         end
 
         begin
-          Process.clock_gettime(Process::CLOCK_THREAD_CPUTIME_ID)
+          Process.clock_gettime(Process::CLOCK_THREAD_CPUTIME_ID, :float_millisecond)
 
           def now_cpu
-            Process.clock_gettime(Process::CLOCK_THREAD_CPUTIME_ID)
+            Process.clock_gettime(Process::CLOCK_THREAD_CPUTIME_ID, :float_millisecond)
           end
         rescue
           def now_cpu
-            0
+            0.0
           end
         end
 

activesupport/test/notifications_test.rb

@@ -434,12 +434,11 @@ def test_event_is_pushed_even_without_block
 
   class EventTest < TestCase
     def test_events_are_initialized_with_details
-      time = Time.now
+      time = Time.now.to_f
       event = event(:foo, time, time + 0.01, random_id, {})
 
       assert_equal :foo, event.name
-      assert_equal time, event.time
-      assert_in_delta 10.0, event.duration, 0.00001
+      assert_in_delta 10.0, event.duration, 0.0001
     end
 
     def test_event_cpu_time_does_not_raise_error_when_start_or_finished_not_called