[SPARK-10001] [CORE] Allow Ctrl-C in spark-shell to kill running job

core/src/main/scala/org/apache/spark/scheduler/JobWaiter.scala

@@ -17,6 +17,12 @@
 
 package org.apache.spark.scheduler
 
+import scala.util.{Failure, Success, Try}
+
+import org.apache.spark.Logging
+
+import sun.misc.{Signal, SignalHandler}
+
 /**
  * An object that waits for a DAGScheduler job to complete. As tasks finish, it passes their
  * results to the given handler function.
@@ -28,6 +34,28 @@ private[spark] class JobWaiter[T](
     resultHandler: (Int, T) => Unit)
   extends JobListener {
 
+  private val sigint: Signal = new Signal("INT")
+  @volatile
+  private var _originalHandler: SignalHandler = null
+
+  def attachSigintHandler(): Unit = {
+    _originalHandler = Signal.handle(sigint, new SignalHandler with Logging {
+      override def handle(signal: Signal): Unit = {
+        logInfo("Cancelling running job.. This might take some time, so be patient. " +
+          "Press Ctrl-C again to kill JVM.")
+        // Detach sigint handler so that pressing ctrl-c again will interrupt the jvm.
+        detachSigintHandler()
+        cancel()
+      }
+    })
+  }
+
+  def detachSigintHandler(): Unit = {
+    if (_originalHandler != null) {
+      Signal.handle(sigint, _originalHandler)
+    }
+  }
+
   private var finishedTasks = 0
 
   // Is the job as a whole finished (succeeded or failed)?
@@ -69,9 +97,14 @@ private[spark] class JobWaiter[T](
   }
 
   def awaitResult(): JobResult = synchronized {
+    val attachTry = Try(attachSigintHandler())
     while (!_jobFinished) {
       this.wait()
     }
+    attachTry match {
+      case _: Success[_] => detachSigintHandler()
+      case _: Failure[_] => // Ignore error. Signal handler is on a best effort basis.
+    }
     return jobResult
   }
 }