Add a method to wait for the finish of the experiment (waitForFinish).

src/main/scala/com/databricks/spark/sql/perf/runBenchmarks.scala

@@ -16,13 +16,14 @@
 
 package com.databricks.spark.sql.perf
 
+import scala.concurrent._
+import scala.concurrent.duration._
+import scala.concurrent.ExecutionContext.Implicits.global
+
 import org.apache.hadoop.conf.Configuration
 import org.apache.hadoop.fs.{Path, FileSystem}
 import org.apache.spark.sql.SQLContext
 
-import scala.concurrent._
-import scala.concurrent.ExecutionContext.Implicits.global
-
 /**
  * The configuration used for an iteration of an experiment.
  * @param sparkVersion The version of Spark.
@@ -256,6 +257,11 @@ abstract class Dataset(
         resultsTable
       }
 
+      /** Waits for the finish of the experiment. */
+      def waitForFinish(timeoutInSeconds: Int) = {
+        Await.result(resultsFuture, timeoutInSeconds.seconds)
+      }
+
       /** Returns results from an actively running experiment. */
       def getCurrentResults() = {
         val tbl = sqlContext.createDataFrame(currentResults)