2 files changed, 130 insertions, 0 deletions
diff --git a/kamon-core/src/main/scala/kamon/metrics/DispatcherMetrics.scala b/kamon-core/src/main/scala/kamon/metrics/DispatcherMetrics.scala
new file mode 100644
index 00000000..77a1c99b
--- /dev/null
+++ b/kamon-core/src/main/scala/kamon/metrics/DispatcherMetrics.scala
@@ -0,0 +1,71 @@
+/*
+ * =========================================================================================
+ * Copyright © 2013-2014 the kamon project <http://kamon.io/>
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file
+ * except in compliance with the License. You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software distributed under the
+ * License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,
+ * either express or implied. See the License for the specific language governing permissions
+ * and limitations under the License.
+ * =========================================================================================
+ */
+
+package kamon.metrics
+
+import com.typesafe.config.Config
+import org.HdrHistogram.HdrRecorder
+
+case class DispatcherMetrics(name: String) extends MetricGroupIdentity {
+  val category = DispatcherMetrics
+}
+
+object DispatcherMetrics extends MetricGroupCategory {
+  val name = "dispatcher"
+
+  case object MaximunPoolSize extends MetricIdentity { val name, tag = "maximum-pool-size" }
+  case object RunningThreadCount extends MetricIdentity { val name, tag = "running-thread-count" }
+  case object QueueTaskCount extends MetricIdentity { val name, tag = "queued-task-count" }
+  case object PoolSize extends MetricIdentity { val name, tag = "pool-size" }
+
+  case class DispatcherMetricRecorder(maximumPoolSize: MetricRecorder, runningThreadCount: MetricRecorder, queueTaskCount: MetricRecorder, poolSize: MetricRecorder)
+      extends MetricGroupRecorder {
+
+    def collect: MetricGroupSnapshot = {
+      DispatcherMetricSnapshot(maximumPoolSize.collect(), runningThreadCount.collect(), queueTaskCount.collect(), poolSize.collect())
+    }
+  }
+
+  case class DispatcherMetricSnapshot(maximumPoolSize: MetricSnapshotLike, runningThreadCount: MetricSnapshotLike, queueTaskCount: MetricSnapshotLike, poolSize: MetricSnapshotLike)
+      extends MetricGroupSnapshot {
+
+    val metrics: Map[MetricIdentity, MetricSnapshotLike] = Map(
+      (MaximunPoolSize -> maximumPoolSize),
+      (RunningThreadCount -> runningThreadCount),
+      (QueueTaskCount -> queueTaskCount),
+      (PoolSize -> poolSize))
+  }
+
+  val Factory = new MetricGroupFactory {
+    type GroupRecorder = DispatcherMetricRecorder
+
+    def create(config: Config): DispatcherMetricRecorder = {
+      val settings = config.getConfig("precision.dispatcher")
+
+      val threadCountConfig = extractPrecisionConfig(settings.getConfig("maximum-pool-size"))
+      val RunningThreadCountConfig = extractPrecisionConfig(settings.getConfig("running-thread-count"))
+      val QueueTaskCountConfig = extractPrecisionConfig(settings.getConfig("queued-task-count"))
+      val PoolSizeConfig = extractPrecisionConfig(settings.getConfig("pool-size"))
+
+      new DispatcherMetricRecorder(
+        HdrRecorder(threadCountConfig.highestTrackableValue, threadCountConfig.significantValueDigits, Scale.Unit),
+        HdrRecorder(RunningThreadCountConfig.highestTrackableValue, RunningThreadCountConfig.significantValueDigits, Scale.Unit),
+        HdrRecorder(QueueTaskCountConfig.highestTrackableValue, QueueTaskCountConfig.significantValueDigits, Scale.Unit),
+        HdrRecorder(PoolSizeConfig.highestTrackableValue, PoolSizeConfig.significantValueDigits, Scale.Unit))
+    }
+  }
+}
+
diff --git a/kamon-core/src/main/scala/kamon/metrics/dispatcher/DispatcherMetricsCollector.scala b/kamon-core/src/main/scala/kamon/metrics/dispatcher/DispatcherMetricsCollector.scala
new file mode 100644
index 00000000..e7edce51
--- /dev/null
+++ b/kamon-core/src/main/scala/kamon/metrics/dispatcher/DispatcherMetricsCollector.scala
@@ -0,0 +1,59 @@
+package kamon.metrics.dispatcher
+
+/*
+ * =========================================================================================
+ * Copyright © 2013-2014 the kamon project <http://kamon.io/>
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file
+ * except in compliance with the License. You may obtain a copy of the License at
+ *
+ *  http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software distributed under the
+ * License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,
+ * either express or implied. See the License for the specific language governing permissions
+ * and limitations under the License.
+ * =========================================================================================
+ */
+
+import scala.concurrent.forkjoin.ForkJoinPool
+import java.util.concurrent.ThreadPoolExecutor
+import akka.dispatch.{ExecutorServiceDelegate, Dispatcher, MessageDispatcher}
+import java.lang.reflect.Method
+
+object DispatcherMetricsCollector {
+
+  private[this] type DispatcherMetrics = (Long, Long, Long, Long)
+
+  private[this] def collectForkJoinMetrics(pool: ForkJoinPool):DispatcherMetrics = {
+    (pool.getParallelism, pool.getActiveThreadCount, (pool.getQueuedTaskCount + pool.getQueuedSubmissionCount), pool.getPoolSize)
+  }
+  private[this] def collectExecutorMetrics(pool: ThreadPoolExecutor):DispatcherMetrics = {
+    (pool.getMaximumPoolSize, pool.getActiveCount, pool.getQueue.size(), pool.getPoolSize)
+  }
+
+  private[this] val executorServiceMethod: Method = {
+    // executorService is protected
+    val method = classOf[Dispatcher].getDeclaredMethod("executorService")
+    method.setAccessible(true)
+    method
+  }
+
+  def collect(dispatcher: MessageDispatcher): (Long, Long, Long, Long) = {
+    dispatcher match {
+      case x: Dispatcher ⇒ {
+        val executor = executorServiceMethod.invoke(x) match {
+          case delegate: ExecutorServiceDelegate ⇒ delegate.executor
+          case other ⇒ other
+        }
+
+        executor match {
+          case fjp: ForkJoinPool ⇒ collectForkJoinMetrics(fjp)
+          case tpe: ThreadPoolExecutor ⇒ collectExecutorMetrics(tpe)
+          case anything ⇒ (0L, 0L, 0L, 0L)
+        }
+      }
+      case _ ⇒ new DispatcherMetrics(0L, 0L, 0L, 0L)
+    }
+  }
+}