* Introduce Java 8 Unsafe intrinsics in LogAdder (lock addq and lock xchg)

* Introduce atomic variant of LongAdder::sumThenReset -> LongAdder::sumAndReset
* Remove LongMaxUpdater in favor to AtomicLongMaxUpdater

3 files changed, 12 insertions, 19 deletions

diff --git a/kamon-core/src/main/scala/kamon/metric/Counter.scala b/kamon-core/src/main/scala/kamon/metric/Counter.scala
index bbcce858..b5f8353c 100644
--- a/kamon-core/src/main/scala/kamon/metric/Counter.scala
+++ b/kamon-core/src/main/scala/kamon/metric/Counter.scala
@@ -15,9 +15,8 @@
 
 package kamon.metric
 
-import java.util.concurrent.atomic.LongAdder
-
 import com.typesafe.scalalogging.StrictLogging
+import kamon.jsr166.LongAdder
 import kamon.util.MeasurementUnit
 
 trait Counter {
@@ -36,12 +35,9 @@ class LongAdderCounter(name: String, tags: Map[String, String], val measurementU
     adder.increment()
 
   def increment(times: Long): Unit = {
-    if (times >= 0)
-      adder.add(times)
-    else
-      logger.warn(s"Ignored attempt to decrement counter [$name]")
+    if (times >= 0) adder.add(times)
+    else logger.warn(s"Ignored attempt to decrement counter [$name]")
   }
 
-  def snapshot(): MetricValue =
-    MetricValue(name, tags, measurementUnit, adder.sumThenReset())
+  def snapshot(): MetricValue = MetricValue(name, tags, measurementUnit, adder.sumAndReset())
 }
diff --git a/kamon-core/src/main/scala/kamon/metric/InstrumentFactory.scala b/kamon-core/src/main/scala/kamon/metric/InstrumentFactory.scala
index 6e95af75..4bd151d3 100644
--- a/kamon-core/src/main/scala/kamon/metric/InstrumentFactory.scala
+++ b/kamon-core/src/main/scala/kamon/metric/InstrumentFactory.scala
@@ -34,7 +34,7 @@ private[kamon] class InstrumentFactory private (defaultHistogramDynamicRange: Dy
 
   def buildMinMaxCounter(dynamicRange: Option[DynamicRange], sampleInterval: Option[Duration])
       (name: String, tags: Map[String, String], unit: MeasurementUnit): SnapshotableMinMaxCounter =
-    new PaddedMinMaxCounter(
+    new SimpleMinMaxCounter(
       name,
       tags,
       buildHistogram(dynamicRange.orElse(Some(defaultMMCounterDynamicRange)))(name, tags, unit),
@@ -93,8 +93,7 @@ object InstrumentFactory {
       if (metricConfig.hasPath("significant-value-digits")) Some(metricConfig.getInt("significant-value-digits")) else None,
       if (metricConfig.hasPath("sample-interval")) Some(metricConfig.getDuration("sample-interval", TimeUnit.MILLISECONDS).millis) else None
     )
-
-    (metricName -> customSettings)
+    metricName -> customSettings
   }
 
   private def readDynamicRange(config: Config): DynamicRange =
diff --git a/kamon-core/src/main/scala/kamon/metric/MinMaxCounter.scala b/kamon-core/src/main/scala/kamon/metric/MinMaxCounter.scala
index 211a1916..ae12f635 100644
--- a/kamon-core/src/main/scala/kamon/metric/MinMaxCounter.scala
+++ b/kamon-core/src/main/scala/kamon/metric/MinMaxCounter.scala
@@ -18,8 +18,7 @@ package kamon.metric
 import java.lang.Math.abs
 import java.util.concurrent.atomic.AtomicLong
 
-import kamon.jsr166.LongMaxUpdater
-import kamon.util.MeasurementUnit
+import kamon.util.{AtomicLongMaxUpdater, MeasurementUnit}
 
 import scala.concurrent.duration.Duration
 
@@ -35,12 +34,11 @@ trait MinMaxCounter {
   def sample(): Unit
 }
 
+class SimpleMinMaxCounter(name: String, tags: Map[String, String], underlyingHistogram: Histogram with DistributionSnapshotInstrument,
+                          val sampleInterval: Duration) extends SnapshotableMinMaxCounter {
 
-class PaddedMinMaxCounter(name: String, tags: Map[String, String], underlyingHistogram: Histogram with DistributionSnapshotInstrument,
-    val sampleInterval: Duration) extends SnapshotableMinMaxCounter {
-
-  private val min = new LongMaxUpdater(0L)
-  private val max = new LongMaxUpdater(0L)
+  private val min = AtomicLongMaxUpdater()
+  private val max = AtomicLongMaxUpdater()
   private val sum = new AtomicLong()
 
   def dynamicRange: DynamicRange =
@@ -88,4 +86,4 @@ class PaddedMinMaxCounter(name: String, tags: Map[String, String], underlyingHis
     underlyingHistogram.record(currentMin)
     underlyingHistogram.record(currentMax)
   }
-}
\ No newline at end of file
+}