1 files changed, 28 insertions, 7 deletions
diff --git a/kamon-core/src/main/scala/kamon/metric/EntityRecorder.scala b/kamon-core/src/main/scala/kamon/metric/EntityRecorder.scala
index 8ce37082..ccdb463e 100644
--- a/kamon-core/src/main/scala/kamon/metric/EntityRecorder.scala
+++ b/kamon-core/src/main/scala/kamon/metric/EntityRecorder.scala
@@ -1,11 +1,13 @@
 package kamon.metric
 
 import java.time.Duration
+import java.util.concurrent.{ScheduledExecutorService, ScheduledFuture, TimeUnit}
 
 import kamon.metric.instrument._
 import kamon.util.MeasurementUnit
 
 import scala.collection.concurrent.TrieMap
+import scala.util.Try
 
 trait EntityRecorder {
   def histogram(name: String): Histogram
@@ -25,12 +27,11 @@ trait EntitySnapshotProducer {
   def snapshot(): EntitySnapshot
 }
 
+class DefaultEntityRecorder(entity: Entity, instrumentFactory: InstrumentFactory, scheduler: ScheduledExecutorService)
+    extends EntityRecorder with EntitySnapshotProducer {
 
-
-
-class DefaultEntityRecorder(entity: Entity, instrumentFactory: InstrumentFactory) extends EntityRecorder with EntitySnapshotProducer {
   private val histograms = TrieMap.empty[String, Histogram with DistributionSnapshotInstrument]
-  private val minMaxCounters = TrieMap.empty[String, MinMaxCounter with DistributionSnapshotInstrument]
+  private val minMaxCounters = TrieMap.empty[String, MinMaxCounterEntry]
   private val counters = TrieMap.empty[String, Counter with SingleValueSnapshotInstrument]
   private val gauges = TrieMap.empty[String, Gauge with SingleValueSnapshotInstrument]
 
@@ -41,10 +42,14 @@ class DefaultEntityRecorder(entity: Entity, instrumentFactory: InstrumentFactory
     histograms.atomicGetOrElseUpdate(name, instrumentFactory.buildHistogram(entity, name, dynamicRange, measurementUnit))
 
   def minMaxCounter(name: String): MinMaxCounter =
-    minMaxCounters.atomicGetOrElseUpdate(name, instrumentFactory.buildMinMaxCounter(entity, name))
+    minMaxCounters.atomicGetOrElseUpdate(name,
+      createMMCounterEntry(instrumentFactory.buildMinMaxCounter(entity, name))
+    ).mmCounter
 
   def minMaxCounter(name: String, measurementUnit: MeasurementUnit, dynamicRange: DynamicRange, sampleFrequency: Duration): MinMaxCounter =
-    minMaxCounters.atomicGetOrElseUpdate(name, instrumentFactory.buildMinMaxCounter(entity, name, dynamicRange, sampleFrequency, measurementUnit))
+    minMaxCounters.atomicGetOrElseUpdate(name,
+      createMMCounterEntry(instrumentFactory.buildMinMaxCounter(entity, name, dynamicRange, sampleFrequency, measurementUnit))
+    ).mmCounter
 
   def gauge(name: String): Gauge =
     gauges.atomicGetOrElseUpdate(name, instrumentFactory.buildGauge(entity, name))
@@ -62,8 +67,24 @@ class DefaultEntityRecorder(entity: Entity, instrumentFactory: InstrumentFactory
     new EntitySnapshot(
       entity,
       histograms = histograms.values.map(_.snapshot()).toSeq,
-      minMaxCounters = minMaxCounters.values.map(_.snapshot()).toSeq,
+      minMaxCounters = minMaxCounters.values.map(_.mmCounter.snapshot()).toSeq,
       gauges = gauges.values.map(_.snapshot()).toSeq,
       counters = counters.values.map(_.snapshot()).toSeq
     )
+
+  def cleanup(): Unit = {
+    minMaxCounters.values.foreach { mmCounter =>
+      Try(mmCounter.refreshFuture.cancel(true))
+    }
+  }
+
+  private case class MinMaxCounterEntry(mmCounter: MinMaxCounter with DistributionSnapshotInstrument, refreshFuture: ScheduledFuture[_])
+
+  private def createMMCounterEntry(mmCounter: MinMaxCounter with DistributionSnapshotInstrument): MinMaxCounterEntry = {
+    val refreshFuture = scheduler.schedule(new Runnable {
+      override def run(): Unit = mmCounter.sample()
+    }, mmCounter.sampleInterval.toMillis, TimeUnit.MILLISECONDS)
+
+    MinMaxCounterEntry(mmCounter, refreshFuture)
+  }
 }
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