DiscardOldestPolicy.java

/**
 * Copyright (c) 2000-present Liferay, Inc. All rights reserved.
 *
 * This library is free software; you can redistribute it and/or modify it under
 * the terms of the GNU Lesser General Public License as published by the Free
 * Software Foundation; either version 2.1 of the License, or (at your option)
 * any later version.
 *
 * This library is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
 * FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more
 * details.
 */

package com.liferay.portal.kernel.concurrent;

/**
 * Implements the same behavior as {@link
 * java.util.concurrent.ThreadPoolExecutor.DiscardOldestPolicy}.
 *
 * @author Shuyang Zhou
 * @see    java.util.concurrent.ThreadPoolExecutor.DiscardOldestPolicy
 */
public class DiscardOldestPolicy implements RejectedExecutionHandler {

	/**
	 * @see java.util.concurrent.ThreadPoolExecutor.DiscardOldestPolicy#rejectedExecution(
	 *      Runnable, java.util.concurrent.ThreadPoolExecutor)
	 */
	@Override
	public void rejectedExecution(
		Runnable runnable, ThreadPoolExecutor threadPoolExecutor) {

		if (threadPoolExecutor.isShutdown()) {
			return;
		}

		TaskQueue<Runnable> taskQueue = threadPoolExecutor.getTaskQueue();

		taskQueue.poll();

		threadPoolExecutor.execute(runnable);
	}

}