org.apache.flink.runtime.state.gemini.engine.rm.AbstractGByteBufferReference Maven / Gradle / Ivy

Show more of this group Show more artifacts with this name
Show all versions of flink-runtime_2.11 Show documentation

There is a newer version: 1.5.1

/*
 * 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.flink.runtime.state.gemini.engine.rm;

import org.apache.flink.runtime.state.gemini.engine.exceptions.GeminiRuntimeException;

/**
 * GByteBuffer.
 */
public abstract class AbstractGByteBufferReference extends AbstractReferenceCountable implements GByteBuffer {
	private volatile long seqID;
	protected final Allocator allocator;

	public AbstractGByteBufferReference(Allocator allocator) {
		this.allocator = allocator;
	}

	@Override
	public void release() throws GeminiRuntimeException {
		//Notice: not thread safe.
		//when release to 0, we will do the logic described by GarbageReleaseeManager. and it's processed by allocator.
		int count = decrementAndGetRefCnt();
		//allocator is null, means not need to release space.
		if (count == 0) {
			if (allocator != null) {
				allocator.release(this);
			} else {
				doFree();
			}
		}
	}

	/**
	 * Notice: Any Wrapper defined inside a {@link Finalizable} itself should be static. Otherwise the instance of a wrapper
	 * will contain a pointer of {@link Finalizable} object, so that gc will not collect it.
	 */
	public static class EmptyCleaner implements FinalizableCleaner {
		@Override
		public void clean() {
		}

		@Override
		public boolean cleaned() {
			return true;
		}

		@Override
		public void cleanedByLeakDetector() {}
	}

	@Override
	public void close() {
		release();
	}

	@Override
	public boolean canSyncFree() {
		return false;
	}

	@Override
	public void setSeqID(long seqID) {
		this.seqID = seqID;
	}

	@Override
	public long getSeqID() {
		return this.seqID;
	}

	@Override
	public void setWaitSeqId() {
	}
}