Remove the need for threads for meters

thanks to the wonderful work in codahale/metrics@c72830f27
eric · Oct 23, 2012 · 4097953 · 4097953
1 parent eb336ed
commit 4097953
Showing 1 changed file with 23 additions and 11 deletions.
diff --git a/lib/metriks/meter.rb b/lib/metriks/meter.rb
@@ -4,25 +4,22 @@
 
 module Metriks
   class Meter
+    TICK_INTERVAL = 5.0
+
     def initialize(averager_klass = Metriks::EWMA)
       @count = Atomic.new(0)
-      @start_time = Time.now
+      @start_time = Time.now.to_f
+      @last_tick = Atomic.new(@start_time)
 
       @m1_rate  = averager_klass.new_m1
       @m5_rate  = averager_klass.new_m5
       @m15_rate = averager_klass.new_m15
-
-      @thread = Thread.new do
-        loop do
-          sleep averager_klass::INTERVAL
-          tick
-        end
-      end
     end
 
     def clear
       @count.value = 0
-      @start_time = Time.now
+      @start_time = Time.now.to_f
+      @last_tick.value = @start_time
       @m1_rate.clear
       @m5_rate.clear
       @m15_rate.clear
@@ -34,7 +31,20 @@ def tick
       @m15_rate.tick
     end
 
+    def tick_if_nessesary
+      old_tick = @last_tick.value
+      new_tick = Time.new.to_f
+      age = new_tick - old_tick
+      if age > TICK_INTERVAL && @last_tick.compare_and_swap(old_tick, new_tick)
+        required_ticks = age / TICK_INTERVAL
+        required_ticks.to_i.times do
+          tick
+        end
+      end
+    end
+
     def mark(val = 1)
+      tick_if_nessesary
       @count.update { |v| v + val }
       @m1_rate.update(val)
       @m5_rate.update(val)
@@ -46,28 +56,30 @@ def count
     end
 
     def one_minute_rate
+      tick_if_nessesary
       @m1_rate.rate
     end
 
     def five_minute_rate
+      tick_if_nessesary
       @m5_rate.rate
     end
 
     def fifteen_minute_rate
+      tick_if_nessesary
       @m15_rate.rate
     end
 
     def mean_rate
       if count == 0
         return 0.0
       else
-        elapsed = Time.now - @start_time
+        elapsed = Time.now.to_f - @start_time
         count / elapsed
       end
     end
 
     def stop
-      @thread.kill
     end
   end
 end