Merge pull request #508 from ivantopo/issue#502/allow-jvm-to-shutdown-when-no-reporters

turn all Kamon threads into daemon threads, except for reporters

1 files changed, 67 insertions, 0 deletions

diff --git a/kamon-core-tests/src/test/scala/kamon/KamonLifecycleSpec.scala b/kamon-core-tests/src/test/scala/kamon/KamonLifecycleSpec.scala
new file mode 100644
index 00000000..b5d0425b
--- /dev/null
+++ b/kamon-core-tests/src/test/scala/kamon/KamonLifecycleSpec.scala
@@ -0,0 +1,67 @@
+package kamon
+
+import java.io.File
+import java.util.concurrent.TimeUnit
+
+import com.typesafe.config.Config
+import kamon.metric.PeriodSnapshot
+import kamon.trace.Span
+import org.scalatest.{Matchers, WordSpec}
+import org.scalatest.concurrent.Eventually
+import org.scalatest.time.SpanSugar._
+
+class KamonLifecycleSpec extends WordSpec with Matchers with Eventually{
+
+  "the Kamon lifecycle" should {
+    "keep the JVM running if reporters are running" in {
+      val process = Runtime.getRuntime.exec(createProcessCommand("kamon.KamonWithRunningReporter"))
+      Thread.sleep(5000)
+      process.isAlive shouldBe true
+      process.destroyForcibly().waitFor(5, TimeUnit.SECONDS)
+    }
+
+    "let the JVM stop after all reporters are stopped" in {
+      val process = Runtime.getRuntime.exec(createProcessCommand("kamon.KamonWithTemporaryReporter"))
+      Thread.sleep(2000)
+      process.isAlive shouldBe true
+
+      eventually(timeout(7 seconds)) {
+        process.isAlive shouldBe false
+        process.exitValue() shouldBe 0
+      }
+    }
+  }
+
+
+  def createProcessCommand(mainClass: String): String = {
+    System.getProperty("java.home") + File.separator + "bin" + File.separator + "java" +
+    " -cp " + System.getProperty("java.class.path") + " " + mainClass
+  }
+}
+
+class DummyMetricReporter extends MetricReporter {
+  override def start(): Unit = {}
+  override def stop(): Unit = {}
+  override def reconfigure(config: Config): Unit = {}
+  override def reportPeriodSnapshot(snapshot: PeriodSnapshot): Unit = {}
+}
+
+class DummySpanReporter extends SpanReporter {
+  override def start(): Unit = {}
+  override def stop(): Unit = {}
+  override def reconfigure(config: Config): Unit = {}
+  override def reportSpans(spans: Seq[Span.FinishedSpan]): Unit = {}
+}
+
+object KamonWithRunningReporter extends App {
+  Kamon.addReporter(new DummyMetricReporter())
+  Kamon.addReporter(new DummySpanReporter())
+}
+
+object KamonWithTemporaryReporter extends App {
+  Kamon.addReporter(new DummyMetricReporter())
+  Kamon.addReporter(new DummySpanReporter())
+
+  Thread.sleep(5000)
+  Kamon.stopAllReporters()
+}