Merge 9d7ac26 into 3a36a8f

src/main/scala/com/tritondigital/counters/JitteredScheduler.scala

@@ -26,7 +26,13 @@ class JitteredScheduler(system: ActorSystem, action: => Unit) extends Runnable {
       action
     }
     finally {
-      system.scheduler.scheduleOnce(nextInterval, this)
+      try {
+        // Catch execption on shutdown
+        system.scheduler.scheduleOnce(nextInterval, this)
+      } catch {
+        case is:IllegalStateException if is.getMessage == "cannot enqueue after timer shutdown" => // ignore
+        case ex:Throwable => throw ex
+      }
     }
   }
 

src/test/scala/com/tritondigital/counters/JitteredSchedulerTest.scala

@@ -0,0 +1,59 @@
+package com.tritondigital.counters
+
+import java.util.concurrent.TimeUnit
+
+import org.scalatest.WordSpec
+import _root_.akka.actor.ActorSystem
+import com.typesafe.config.{Config, ConfigFactory, ConfigValueFactory}
+
+class JitteredSchedulerTest extends WordSpec with CustomMatchers {
+
+  "The Jittered Scheduler" should {
+    "schedule the given action with jitter" in withSut(ConfigFactory
+      .load()
+      .withValue("tritondigital_counters.publish_interval",ConfigValueFactory.fromAnyRef(100))
+      .withValue("tritondigital_counters.publish_interval_jitter", ConfigValueFactory.fromAnyRef(0.20))) { sut =>
+      sut.scheduler.start()
+      val publish_interval = sut.system.settings.config.getDuration("tritondigital_counters.publish_interval", TimeUnit.MILLISECONDS)
+      Thread.sleep(publish_interval * 10)
+      sut.mock.count should be (10 +- 2)
+    }
+
+    "not crash" in withSut(ConfigFactory
+      .load()
+      .withValue("tritondigital_counters.publish_interval", ConfigValueFactory.fromAnyRef(100))
+      .withValue("tritondigital_counters.publish_interval_jitter", ConfigValueFactory.fromAnyRef(0.25))) { sut =>
+      sut.scheduler.start()
+      val publish_interval = sut.system.settings.config.getDuration("tritondigital_counters.publish_interval", TimeUnit.MILLISECONDS)
+      Thread.sleep(publish_interval * 10)
+      sut.system.shutdown()
+      Thread.sleep(1000)
+      sut.mock.count should be (10 +- 3)
+    }
+
+    "raise an exception" in withSut(ConfigFactory
+      .load()
+      .withValue("tritondigital_counters.publish_interval", ConfigValueFactory.fromAnyRef(Long.MaxValue))
+      .withValue("tritondigital_counters.publish_interval_jitter", ConfigValueFactory.fromAnyRef(0.25))) { sut =>
+      sut.scheduler.start()
+      a[IllegalArgumentException] should be thrownBy sut.scheduler.run()
+    }
+  }
+
+  case class Sut(system: ActorSystem, mock: ActionMock, scheduler: JitteredScheduler)
+
+  def withSut(config: Config)(f: Sut => Unit) = {
+    val system = ActorSystem("JitteredScheduler", config)
+    val mock = new ActionMock()
+    val scheduler = new JitteredScheduler(system, mock.action())
+    f(Sut(system, mock, scheduler))
+  }
+
+  class ActionMock {
+    var count = 0
+    def action() = {
+      count += 1
+    }
+  }
+
+}