TaskTimeoutThread.java

/**
 * File ./src/main/java/de/lemo/dms/processing/TaskTimeoutThread.java
 * Lemo-Data-Management-Server for learning analytics.
 * Copyright (C) 2013
 * Leonard Kappe, Andreas Pursian, Sebastian Schwarzrock, Boris Wenzlaff
 * 
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * any later version.
 * 
 * This program 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 General Public License for more details.
 * 
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
**/

/**
 * File ThreadPoolTimeoutThread.java
 * Date 24.04.2013
 * Project Lemo Learning Analytics
 */
package de.lemo.dms.processing;

import java.util.Date;
import java.util.Iterator;
import java.util.Map;
import java.util.Map.Entry;
import org.apache.log4j.Logger;

/**
 * Thread to remove old results. Check the task results creation date and removes any results that exceeded their life
 * time.
 * 
 * @author Boris Wenzlaff
 * @author Leonard Kappe
 */
public class TaskTimeoutThread extends Thread {

	// arbitrary check every 5 seconds
	private static final int CHECK_INTERVALL = 5000;
	private static final String NAME = "BideResultTimeout";

	private final Logger logger = Logger.getLogger(getClass());

	private Map<String, AnalysisTask> tasks;
	private long maxProcessingTime;
	private long maxResultLifeTime;

	public TaskTimeoutThread(Map<String, AnalysisTask> tasks, long maxProcessingTime, long maxResultLifeTime) {
		super(NAME);
		this.tasks = tasks;
		this.maxProcessingTime = maxProcessingTime;
		this.maxResultLifeTime = maxResultLifeTime;
	}

	public void run() {
		try {
			while (true) {
				// sleep some arbitrary time
				Thread.sleep(CHECK_INTERVALL);

				synchronized (tasks) {
					logger.trace("Running timout check for " + tasks.size() + " tasks.");
					
					for (Iterator<Entry<String, AnalysisTask>> iterator = tasks.entrySet().iterator(); iterator
							.hasNext();) {
						Entry<String, AnalysisTask> entry = iterator.next();
						AnalysisTask task = entry.getValue();

						if (task.isRunning()) {
							// check if the computation time reached the limit
							long computationTime = new Date().getTime() - task.getStartTime();
							logger.trace(task + " - computation time " + computationTime + "/" + maxProcessingTime);
							if (computationTime > maxProcessingTime) {
								logger.info(task + "- computation timeout exceeded, task cancelled."
										+ task.getTaskId());

								// cancel the task but don't remove it yet,
								// so the user may get told that it got canceled by a timeout
								task.cancel();
							}
						} else if (task.isDone()) {
							// check if the result life time reached the limit
							long resultLifeTime = new Date().getTime() - task.getEndTime();
							if (task.isDone() && resultLifeTime > maxResultLifeTime) {
								iterator.remove();
								logger.debug(task + " - result lifetime exceeded, result removed.");
							}
						}

					}
				}
			}
		} catch (InterruptedException e) {
			// this thread should never be interrupted, it should run forever
			logger.fatal("Interrupted!", e);
		}

	}
}