undo chnage to onCompleteCallbacks

core/src/main/scala/spark/TaskContext.scala

@@ -7,15 +7,15 @@ class TaskContext(val stageId: Int, val splitId: Int, val attemptId: Long, val t
   //by adding Task here, I'm destroying the separation between Task & TaskContext ... not sure why they need to
   // be separate
 
-  @transient val onCompleteCallbacks = new ArrayBuffer[TaskContext => Unit]
+  @transient val onCompleteCallbacks = new ArrayBuffer[() => Unit]
 
   // Add a callback function to be executed on task completion. An example use
   // is for HadoopRDD to register a callback to close the input stream.
-  def addOnCompleteCallback(f: TaskContext => Unit) {
+  def addOnCompleteCallback(f: () => Unit) {
     onCompleteCallbacks += f
   }
 
   def executeOnCompleteCallbacks() {
-    onCompleteCallbacks.foreach{_.apply(this)}
+    onCompleteCallbacks.foreach{_()}
   }
 }

core/src/main/scala/spark/rdd/CheckpointRDD.scala

@@ -104,7 +104,7 @@ private[spark] object CheckpointRDD extends Logging {
     val deserializeStream = serializer.deserializeStream(fileInputStream)
 
     // Register an on-task-completion callback to close the input stream.
-    context.addOnCompleteCallback(_ => deserializeStream.close())
+    context.addOnCompleteCallback(() => deserializeStream.close())
 
     deserializeStream.asIterator.asInstanceOf[Iterator[T]]
   }

core/src/main/scala/spark/rdd/HadoopRDD.scala

@@ -74,7 +74,7 @@ class HadoopRDD[K, V](
     reader = fmt.getRecordReader(split.inputSplit.value, conf, Reporter.NULL)
 
     // Register an on-task-completion callback to close the input stream.
-    context.addOnCompleteCallback(_ => reader.close())
+    context.addOnCompleteCallback(() => reader.close())
 
     val key: K = reader.createKey()
     val value: V = reader.createValue()

core/src/main/scala/spark/rdd/NewHadoopRDD.scala

@@ -63,7 +63,7 @@ class NewHadoopRDD[K, V](
     reader.initialize(split.serializableHadoopSplit.value, hadoopAttemptContext)
 
     // Register an on-task-completion callback to close the input stream.
-    context.addOnCompleteCallback(_ => reader.close())
+    context.addOnCompleteCallback(() => reader.close())
 
     var havePair = false
     var finished = false