add unit tests

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

@@ -0,0 +1,54 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.apache.spark.scheduler
+
+import org.apache.spark.{SparkConf, SparkException, SparkContext}
+import org.apache.spark.util.{SerializableBuffer, AkkaUtils}
+import org.apache.spark.SparkContext._
+import java.nio.ByteBuffer
+
+import org.scalatest.{BeforeAndAfterAll, BeforeAndAfter, FunSuite}
+class CoarseGrainedSchedulerBackendSuite extends FunSuite with
+BeforeAndAfter with BeforeAndAfterAll {
+
+  override def beforeAll {
+    System.setProperty("spark.akka.frameSize", "1")
+    System.setProperty("spark.default.parallelism", "1")
+
+  }
+
+  override def afterAll {
+    System.clearProperty("spark.akka.frameSize")
+    System.clearProperty("spark.default.parallelism")
+  }
+
+  test("serialized task larger than Akka frame size") {
+    val conf = new SparkConf
+    val sc = new SparkContext("local-cluster[2 , 1 , 512]", "test", conf)
+    val frameSize = AkkaUtils.maxFrameSizeBytes(sc.conf)
+    val buffer = new SerializableBuffer(ByteBuffer.allocate(2 * frameSize))
+    val larger = sc.parallelize(Seq(buffer))
+    val thrown = intercept[SparkException] {
+      larger.collect()
+    }
+    assert(thrown.getMessage.contains("Consider using broadcast variables for large values"))
+    val smaller = sc.parallelize(1 to 4).collect()
+    assert(smaller.size === 4)
+  }
+
+}