Merge pull request alteryx#241 from pwendell/branch-0.8

Fix race condition in JobLoggerSuite [0.8 branch]

I found this when running the tests locally. It's similar to a race condition found when making the 0.8.0 release.

Author: pwendell

core/src/test/scala/org/apache/spark/scheduler/JobLoggerSuite.scala

@@ -31,6 +31,8 @@ import org.apache.spark.rdd.RDD
 
 
 class JobLoggerSuite extends FunSuite with LocalSparkContext with ShouldMatchers {
+  /** Length of time to wait while draining listener events. */
+  val WAIT_TIMEOUT_MILLIS = 10000
 
   test("inner method") {
     sc = new SparkContext("local", "joblogger")
@@ -91,6 +93,7 @@ class JobLoggerSuite extends FunSuite with LocalSparkContext with ShouldMatchers
     sc.addSparkListener(joblogger)
     val rdd = sc.parallelize(1 to 1e2.toInt, 4).map{ i => (i % 12, 2 * i) }
     rdd.reduceByKey(_+_).collect()
+    assert(sc.dagScheduler.listenerBus.waitUntilEmpty(WAIT_TIMEOUT_MILLIS))
 
     val user = System.getProperty("user.name", SparkContext.SPARK_UNKNOWN_USER)
 
@@ -119,8 +122,9 @@ class JobLoggerSuite extends FunSuite with LocalSparkContext with ShouldMatchers
     }
     sc.addSparkListener(joblogger)
     val rdd = sc.parallelize(1 to 1e2.toInt, 4).map{ i => (i % 12, 2 * i) }
-    rdd.reduceByKey(_+_).collect()
-    
+    rdd.reduceByKey(_+_).collect() 
+    assert(sc.dagScheduler.listenerBus.waitUntilEmpty(WAIT_TIMEOUT_MILLIS))
+
     joblogger.onJobStartCount should be (1)
     joblogger.onJobEndCount should be (1)
     joblogger.onTaskEndCount should be (8)