fr.aliasource.webmail.pool.impl.KeepAliveTask.java Source code

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Here is the source code for fr.aliasource.webmail.pool.impl.KeepAliveTask.java

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/* ***** BEGIN LICENSE BLOCK *****
 * Version: GPL 2.0
 *
 * The contents of this file are subject to the GNU General Public
 * License Version 2 or later (the "GPL").
 *
 * Software distributed under the License is distributed on an "AS IS" basis,
 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
 * for the specific language governing rights and limitations under the
 * License.
 *
 * The Initial Developer of the Original Code is
 *   MiniG.org project members
 *
 * ***** END LICENSE BLOCK ***** */

package fr.aliasource.webmail.pool.impl;

import java.util.LinkedList;
import java.util.TimerTask;
import java.util.concurrent.LinkedBlockingQueue;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

import fr.aliasource.webmail.pool.IPoolable;
import fr.aliasource.webmail.pool.IPoolableObjectFactory;
import fr.aliasource.webmail.pool.Pool;

public class KeepAliveTask<T extends IPoolable> extends TimerTask {

    private LinkedBlockingQueue<T> availableObjects;

    private IPoolableObjectFactory<T> factory;

    private Pool<T> pool;

    private static final Log logger = LogFactory.getLog(KeepAliveTask.class);

    public KeepAliveTask(LinkedBlockingQueue<T> availableObjects, IPoolableObjectFactory<T> factory, Pool<T> pool) {
        this.availableObjects = availableObjects;
        this.factory = factory;
        this.pool = pool;
    }

    @Override
    public void run() {
        LinkedList<T> dead = new LinkedList<T>();

        for (T t : availableObjects) {
            boolean isAlive = t.keepAlive();
            if (!isAlive) {
                logger.warn("Dead poolable item (" + t + "). will recycle.");
                dead.add(t);
            }
        }

        if (!dead.isEmpty()) {
            logger.warn("pool usage report: " + pool.getUsageReport());
        }

        for (T t : dead) {
            availableObjects.remove(t);
            recycle();
        }

        if (availableObjects.remainingCapacity() - pool.getUsageCount() > 0) {
            logger.error("Pool refilling failed this time: " + pool.getUsageReport());
        }
    }

    private void recycle() {
        T recycled = factory.createNewObject();
        if (recycled != null) {
            boolean accepted = availableObjects.offer(recycled);
            if (accepted) {
                logger.info("Dead poolable item (" + recycled + ") recycled.");
            } else {
                try {
                    pool.nativeDestroy(recycled);
                } catch (Throwable t) {
                }
            }
        } else {
            logger.warn("Cannot recycle dead poolable " + "(next keepAliveTask run will retry)");
        }
    }

}