Added SchedulerService class that allows subcla...

Added SchedulerService class that allows subclasses to define custom
shutdown actions.

1 files changed, 94 insertions, 0 deletions

diff --git a/src/actors/scala/actors/SchedulerService.scala b/src/actors/scala/actors/SchedulerService.scala
new file mode 100644
index 0000000000..f885e30b02
--- /dev/null
+++ b/src/actors/scala/actors/SchedulerService.scala
@@ -0,0 +1,94 @@
+/*                     __                                               *\
+**     ________ ___   / /  ___     Scala API                            **
+**    / __/ __// _ | / /  / _ |    (c) 2005-2009, LAMP/EPFL             **
+**  __\ \/ /__/ __ |/ /__/ __ |    http://scala-lang.org/               **
+** /____/\___/_/ |_/____/_/ | |                                         **
+**                          |/                                          **
+\*                                                                      */
+
+// $Id: $
+
+package scala.actors
+
+import java.lang.{Runnable, Thread, InterruptedException}
+
+/**
+ * The abstract <code>SchedulerService</code> class allows
+ * subclasses to implement a custom <code>onShutdown</code>
+ * method, which is invoked when the runtime system has detected
+ * that all actors have been terminated.
+ *
+ * @version 0.9.18
+ * @author Philipp Haller
+ */
+abstract class SchedulerService(daemon: Boolean) extends Thread with IScheduler {
+  setDaemon(daemon)
+
+  def this() =
+    this(false)
+
+  /** The <code>ActorGC</code> instance that keeps track of the
+   *  live actor objects that are managed by <code>this</code>
+   *  scheduler.
+   */
+  val actorGC = new ActorGC
+
+  private var terminating = false
+
+  def printActorDump {}
+
+  protected val CHECK_FREQ = 100
+
+  def onLockup(handler: () => Unit) =
+    lockupHandler = handler
+
+  def onLockup(millis: Int)(handler: () => Unit) = {
+    //LOCKUP_CHECK_FREQ = millis / CHECK_FREQ
+    lockupHandler = handler
+  }
+
+  private var lockupHandler: () => Unit = null
+
+  def onShutdown(): Unit
+
+  override def run() {
+    try {
+      while (!terminating) {
+        this.synchronized {
+          try {
+            wait(CHECK_FREQ)
+          } catch {
+            case _: InterruptedException =>
+              if (terminating) throw new QuitException
+          }
+
+          actorGC.gc()
+
+          if (actorGC.allTerminated) {
+            throw new QuitException
+          }
+        } // sync
+      } // while (!terminating)
+    } catch {
+      case _: QuitException =>
+        Debug.info(this+": initiating shutdown...")
+        // invoke shutdown hook
+        onShutdown()
+        // allow thread to exit
+    }
+  }
+
+  /** Submits a <code>Runnable</code> for execution.
+   *
+   *  @param  task  the task to be executed
+   */
+  def execute(task: Runnable): Unit =
+    execute { task.run() }
+
+  /** Shuts down the scheduler.
+   */
+  def shutdown(): Unit = synchronized {
+    terminating = true
+  }
+
+}