com.sun.enterprise.resource.pool.waitqueue.DefaultPoolWaitQueue Maven / Gradle / Ivy

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package com.sun.enterprise.resource.pool.waitqueue;

import com.sun.logging.LogDomains;

import java.util.Collection;
import java.util.LinkedList;
import java.util.logging.Level;
import java.util.logging.Logger;

/**
 * Default wait queue for the connection pool
 *
 * @author Jagadish Ramu
 */
public class DefaultPoolWaitQueue implements PoolWaitQueue {

    private LinkedList list;
    protected final static Logger _logger = LogDomains.getLogger(DefaultPoolWaitQueue.class, LogDomains.RSR_LOGGER);

    private void initializeDefaultQueue() {
        list = new LinkedList();
        debug("Initializing default Pool Wait Queue");
    }

    public DefaultPoolWaitQueue() {
        initializeDefaultQueue();
    }

    @Override
    public synchronized int getQueueLength() {
        return list.size();
    }

    @Override
    public synchronized void addToQueue(Object waitMonitor) {
        list.addLast(waitMonitor);
    }

    @Override
    public synchronized boolean removeFromQueue(Object o) {
        return list.remove(o);
    }

/*
    public synchronized Object removeFirst() {
        return list.removeFirst();
    }
*/

    @Override
    public synchronized Object remove() {
        return list.removeFirst();
    }

    @Override
    public Object peek() {
        Object result = null;
        if (list.size() > 0) {
            result = list.get(0);
        }
        return result;
    }

    @Override
    public Collection getQueueContents() {
        return list;
    }

    protected void debug(String debugStatement) {
        if(_logger.isLoggable(Level.FINE)) {
            _logger.log(Level.FINE, debugStatement);
        }
    }
}