threadmanagerimpl.java

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package org.roller.business;

import EDU.oswego.cs.dl.util.concurrent.BoundedBuffer;
import EDU.oswego.cs.dl.util.concurrent.DirectExecutor;
import EDU.oswego.cs.dl.util.concurrent.PooledExecutor;
import EDU.oswego.cs.dl.util.concurrent.ThreadFactory;

import java.util.Date;
import java.util.Timer;
import java.util.TimerTask;

import org.roller.model.ThreadManager;
import org.roller.util.DateUtil;

/**
 * Manage Roller's background thread use. Currently, Roller starts background
 * threads for two purposes: 1) the nightly purge of referer counts and 2)
 * following linkbacks (only occurs if linkbacks are enabled).
 *
 * @author aim4min
 */
public class ThreadManagerImpl implements ThreadManager
{
    private PooledExecutor backgroundExecutor;
    private DirectExecutor nodelayExecutor;
    private Timer scheduler;

    public ThreadManagerImpl()
    {
        backgroundExecutor = new PooledExecutor(new BoundedBuffer(10), 25);
        backgroundExecutor.setMinimumPoolSize(4);
        backgroundExecutor.setKeepAliveTime(1000 * 60 * 5);
        backgroundExecutor.waitWhenBlocked();
        backgroundExecutor.createThreads(9);

        backgroundExecutor.setThreadFactory(new ThreadFactory() {
            public Thread newThread(Runnable command)
            {
                Thread t = new Thread(command);
                t.setDaemon(false);
                t.setName("Background Execution Threads");
                t.setPriority(Thread.NORM_PRIORITY);

                return t;
            }
        });

        nodelayExecutor = new DirectExecutor();
        scheduler = new Timer(true);
    }

    public void executeInBackground(Runnable runnable)
            throws InterruptedException
    {
        backgroundExecutor.execute(runnable);
    }

    public void executeInForeground(Runnable runnable)
            throws InterruptedException
    {
        nodelayExecutor.execute(runnable);
    }

    public void scheduleDailyTimerTask(TimerTask task)
    {
        scheduler.scheduleAtFixedRate(task,
                DateUtil.getEndOfDay(new Date()), DateUtil.millisInDay);
    }

    public void scheduleHourlyTimerTask(TimerTask task)
    {
        scheduler.scheduleAtFixedRate(task, new Date(), 60*60*1000);
    }

    public void scheduleFixedRateTimerTask(TimerTask task, long delayMins, long periodMins) {
        if (periodMins < MIN_RATE_INTERVAL_MINS) {
            throw new IllegalArgumentException("Period (" + periodMins +
                ") shorter than minimum allowed (" + MIN_RATE_INTERVAL_MINS + ")");
        }
        scheduler.scheduleAtFixedRate(task, delayMins * 60 * 1000, periodMins * 60 * 1000);
    }

    public void shutdown()
    {
        backgroundExecutor.shutdownAfterProcessingCurrentlyQueuedTasks();
        scheduler.cancel();
    }

    public void release()
    {
    }
}