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Diffstat (limited to 'core/src/main/scala/org/apache/spark/storage/BlockInfo.scala')
-rw-r--r-- | core/src/main/scala/org/apache/spark/storage/BlockInfo.scala | 81 |
1 files changed, 81 insertions, 0 deletions
diff --git a/core/src/main/scala/org/apache/spark/storage/BlockInfo.scala b/core/src/main/scala/org/apache/spark/storage/BlockInfo.scala new file mode 100644 index 0000000000..c8f397609a --- /dev/null +++ b/core/src/main/scala/org/apache/spark/storage/BlockInfo.scala @@ -0,0 +1,81 @@ +/* + * 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.storage + +import java.util.concurrent.ConcurrentHashMap + +private[storage] class BlockInfo(val level: StorageLevel, val tellMaster: Boolean) { + // To save space, 'pending' and 'failed' are encoded as special sizes: + @volatile var size: Long = BlockInfo.BLOCK_PENDING + private def pending: Boolean = size == BlockInfo.BLOCK_PENDING + private def failed: Boolean = size == BlockInfo.BLOCK_FAILED + private def initThread: Thread = BlockInfo.blockInfoInitThreads.get(this) + + setInitThread() + + private def setInitThread() { + // Set current thread as init thread - waitForReady will not block this thread + // (in case there is non trivial initialization which ends up calling waitForReady as part of + // initialization itself) + BlockInfo.blockInfoInitThreads.put(this, Thread.currentThread()) + } + + /** + * Wait for this BlockInfo to be marked as ready (i.e. block is finished writing). + * Return true if the block is available, false otherwise. + */ + def waitForReady(): Boolean = { + if (pending && initThread != Thread.currentThread()) { + synchronized { + while (pending) this.wait() + } + } + !failed + } + + /** Mark this BlockInfo as ready (i.e. block is finished writing) */ + def markReady(sizeInBytes: Long) { + require (sizeInBytes >= 0, "sizeInBytes was negative: " + sizeInBytes) + assert (pending) + size = sizeInBytes + BlockInfo.blockInfoInitThreads.remove(this) + synchronized { + this.notifyAll() + } + } + + /** Mark this BlockInfo as ready but failed */ + def markFailure() { + assert (pending) + size = BlockInfo.BLOCK_FAILED + BlockInfo.blockInfoInitThreads.remove(this) + synchronized { + this.notifyAll() + } + } +} + +private object BlockInfo { + // initThread is logically a BlockInfo field, but we store it here because + // it's only needed while this block is in the 'pending' state and we want + // to minimize BlockInfo's memory footprint. + private val blockInfoInitThreads = new ConcurrentHashMap[BlockInfo, Thread] + + private val BLOCK_PENDING: Long = -1L + private val BLOCK_FAILED: Long = -2L +} |