Merge pull request #232 from markhamstra/FiniteWait

jobWaiter.synchronized before jobWaiter.wait

...else ``IllegalMonitorStateException`` in ``SimpleFutureAction#ready``.

core/src/main/scala/org/apache/spark/FutureAction.scala

@@ -99,7 +99,7 @@ class SimpleFutureAction[T] private[spark](jobWaiter: JobWaiter[_], resultFunc:
   override def ready(atMost: Duration)(implicit permit: CanAwait): SimpleFutureAction.this.type = {
     if (!atMost.isFinite()) {
       awaitResult()
-    } else {
+    } else jobWaiter.synchronized {
       val finishTime = System.currentTimeMillis() + atMost.toMillis
       while (!isCompleted) {
         val time = System.currentTimeMillis()

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

@@ -31,6 +31,7 @@ private[spark] class JobWaiter[T](
   private var finishedTasks = 0
 
   // Is the job as a whole finished (succeeded or failed)?
+  @volatile
   private var _jobFinished = totalTasks == 0
 
   def jobFinished = _jobFinished

core/src/test/scala/org/apache/spark/rdd/AsyncRDDActionsSuite.scala

@@ -19,6 +19,8 @@ package org.apache.spark.rdd
 
 import java.util.concurrent.Semaphore
 
+import scala.concurrent.{Await, TimeoutException}
+import scala.concurrent.duration.Duration
 import scala.concurrent.ExecutionContext.Implicits.global
 
 import org.scalatest.{BeforeAndAfterAll, FunSuite}
@@ -173,4 +175,28 @@ class AsyncRDDActionsSuite extends FunSuite with BeforeAndAfterAll with Timeouts
       sem.acquire(2)
     }
   }
+
+  /**
+   * Awaiting FutureAction results
+   */
+  test("FutureAction result, infinite wait") {
+    val f = sc.parallelize(1 to 100, 4)
+              .countAsync()
+    assert(Await.result(f, Duration.Inf) === 100)
+  }
+
+  test("FutureAction result, finite wait") {
+    val f = sc.parallelize(1 to 100, 4)
+              .countAsync()
+    assert(Await.result(f, Duration(30, "seconds")) === 100)
+  }
+
+  test("FutureAction result, timeout") {
+    val f = sc.parallelize(1 to 100, 4)
+              .mapPartitions(itr => { Thread.sleep(20); itr })
+              .countAsync()
+    intercept[TimeoutException] {
+      Await.result(f, Duration(20, "milliseconds"))
+    }
+  }
 }