[SPARK-5269] [CORE] Use a SerializerInstance pool in BlockManager.

Author: Maciej Kisiel

core/src/main/scala/org/apache/spark/storage/BlockManager.scala

@@ -20,9 +20,12 @@ package org.apache.spark.storage
 import java.io._
 import java.nio.{ByteBuffer, MappedByteBuffer}
 
+import com.twitter.chill.ResourcePool
+
 import scala.collection.mutable.{ArrayBuffer, HashMap}
 import scala.concurrent.{ExecutionContext, Await, Future}
 import scala.concurrent.duration._
+import scala.reflect.ClassTag
 import scala.util.control.NonFatal
 import scala.util.Random
 
@@ -37,7 +40,7 @@ import org.apache.spark.network.netty.SparkTransportConf
 import org.apache.spark.network.shuffle.ExternalShuffleClient
 import org.apache.spark.network.shuffle.protocol.ExecutorShuffleInfo
 import org.apache.spark.rpc.RpcEnv
-import org.apache.spark.serializer.{SerializerInstance, Serializer}
+import org.apache.spark.serializer.{SerializationStream, DeserializationStream, SerializerInstance, Serializer}
 import org.apache.spark.shuffle.ShuffleManager
 import org.apache.spark.shuffle.hash.HashShuffleManager
 import org.apache.spark.util._
@@ -53,6 +56,56 @@ private[spark] class BlockResult(
     val readMethod: DataReadMethod.Value,
     val bytes: Long)
 
+private[storage] class BlockManagerSerializerPool(serializer: Serializer, size: Int)
+    extends ResourcePool[SerializerInstance](size) {
+  override def newInstance(): SerializerInstance = serializer.newInstance()
+}
+
+private[storage] class BlockManagerSerializerInstance(serializer: Serializer)
+    extends SerializerInstance {
+  @transient lazy val instancePool = new BlockManagerSerializerPool(serializer, 30)
+
+  private[this] def acquireRelease[O](fn: SerializerInstance => O): O = {
+    val serializerInstance = instancePool.borrow
+    try {
+      fn(serializerInstance)
+    } finally {
+      instancePool.release(serializerInstance)
+    }
+  }
+
+  def serialize[T: ClassTag](o: T): ByteBuffer =
+    acquireRelease { serializerInstance =>
+      serializerInstance.serialize(o)
+    }
+
+  def deserialize[T: ClassTag](bytes: ByteBuffer): T =
+    acquireRelease { serializerInstance =>
+      serializerInstance.deserialize[T](bytes)
+    }
+
+  override def deserialize[T: ClassTag](bytes: ByteBuffer, loader: ClassLoader): T =
+    acquireRelease { serializerInstance =>
+      serializerInstance.deserialize(bytes, loader)
+    }
+
+  override def serializeStream(s: OutputStream): SerializationStream =
+    acquireRelease { serializerInstance =>
+      serializerInstance.serializeStream(s)
+    }
+
+  override def deserializeStream(s: InputStream): DeserializationStream =
+    acquireRelease { serializerInstance =>
+      serializerInstance.deserializeStream(s)
+    }
+}
+
+private[storage] class BlockManagerSerializer(serializer: Serializer) extends Serializer {
+  val blockManagerSerializerInstance = new BlockManagerSerializerInstance(serializer)
+
+  override def newInstance(): SerializerInstance = blockManagerSerializerInstance
+}
+
 /**
  * Manager running on every node (driver and executors) which provides interfaces for putting and
  * retrieving blocks both locally and remotely into various stores (memory, disk, and off-heap).
@@ -77,6 +130,8 @@ private[spark] class BlockManager(
 
   private val blockInfo = new TimeStampedHashMap[BlockId, BlockInfo]
 
+  private val pooledDefaultSerializer = new BlockManagerSerializer(defaultSerializer)
+
   private val futureExecutionContext = ExecutionContext.fromExecutorService(
     ThreadUtils.newDaemonCachedThreadPool("block-manager-future", 128))
 
@@ -1211,7 +1266,7 @@ private[spark] class BlockManager(
       blockId: BlockId,
       outputStream: OutputStream,
       values: Iterator[Any],
-      serializer: Serializer = defaultSerializer): Unit = {
+      serializer: Serializer = pooledDefaultSerializer): Unit = {
     val byteStream = new BufferedOutputStream(outputStream)
     val ser = serializer.newInstance()
     ser.serializeStream(wrapForCompression(blockId, byteStream)).writeAll(values).close()
@@ -1221,7 +1276,7 @@ private[spark] class BlockManager(
   def dataSerialize(
       blockId: BlockId,
       values: Iterator[Any],
-      serializer: Serializer = defaultSerializer): ByteBuffer = {
+      serializer: Serializer = pooledDefaultSerializer): ByteBuffer = {
     val byteStream = new ByteArrayOutputStream(4096)
     dataSerializeStream(blockId, byteStream, values, serializer)
     ByteBuffer.wrap(byteStream.toByteArray)
@@ -1234,7 +1289,7 @@ private[spark] class BlockManager(
   def dataDeserialize(
       blockId: BlockId,
       bytes: ByteBuffer,
-      serializer: Serializer = defaultSerializer): Iterator[Any] = {
+      serializer: Serializer = pooledDefaultSerializer): Iterator[Any] = {
     bytes.rewind()
     dataDeserializeStream(blockId, new ByteBufferInputStream(bytes, true), serializer)
   }
@@ -1246,7 +1301,7 @@ private[spark] class BlockManager(
   def dataDeserializeStream(
       blockId: BlockId,
       inputStream: InputStream,
-      serializer: Serializer = defaultSerializer): Iterator[Any] = {
+      serializer: Serializer = pooledDefaultSerializer): Iterator[Any] = {
     val stream = new BufferedInputStream(inputStream)
     serializer.newInstance().deserializeStream(wrapForCompression(blockId, stream)).asIterator
   }