de.thischwa.pmcms.view.renderer.ExportThreadPoolController.java Source code

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Here is the source code for de.thischwa.pmcms.view.renderer.ExportThreadPoolController.java

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/*******************************************************************************
 * Poor Man's CMS (pmcms) - A very basic CMS generating static html pages.
 * http://poormans.sourceforge.net
 * Copyright (C) 2004-2013 by Thilo Schwarz
 * 
 * == BEGIN LICENSE ==
 * 
 * Licensed under the terms of any of the following licenses at your
 * choice:
 * 
 *  - GNU Lesser General Public License Version 2.1 or later (the "LGPL")
 *    http://www.gnu.org/licenses/lgpl.html
 * 
 *  - Mozilla Public License Version 1.1 or later (the "MPL")
 *    http://www.mozilla.org/MPL/MPL-1.1.html
 * 
 * == END LICENSE ==
 ******************************************************************************/
package de.thischwa.pmcms.view.renderer;

import java.util.Collection;
import java.util.concurrent.LinkedBlockingQueue;
import java.util.concurrent.TimeUnit;

import org.apache.commons.collections.CollectionUtils;
import org.apache.log4j.Logger;

import de.thischwa.pmcms.Constants;
import de.thischwa.pmcms.tool.ThreadPool;

/**
 * Initializes and feed the thread pool and handle the individual export threads. Just 'maxRunningThreads' are running simultaneous. It provides methods for
 * status information and exception handling.
 * 
 * @author Thilo Schwarz
 */
public class ExportThreadPoolController extends Thread {
    private static Logger logger = Logger.getLogger(ExportThreadPoolController.class);
    private ThreadPool threadPool;
    private Collection<Thread> threads;
    private boolean isError = false;
    private Exception threadException = null;
    private boolean isCanceled = false;

    ExportThreadPoolController(int threadMaxCountPerCore) {
        int threadPoolSize = 1;
        if (threadMaxCountPerCore != 0)
            threadPoolSize = threadMaxCountPerCore * Constants.CPU_COUNT;
        threadPool = new ThreadPool(threadPoolSize, threadPoolSize, 0L, TimeUnit.MILLISECONDS,
                new LinkedBlockingQueue<Runnable>());

        logger.info("ExportThreadPoolController thread pool size initialized with: " + threadPoolSize);
    }

    void addAll(final Collection<Thread> threads) {
        this.threads = threads;
    }

    @Override
    public void run() {
        if (CollectionUtils.isEmpty(threads)) {
            logger.warn("No render threads found.");
            return;
        }

        // feed the pool
        for (Thread thread : threads)
            threadPool.execute(thread);

        threadPool.shutdown();

        logger.debug("Thread pool initialized!");
    }

    int getTerminatedThreadCount() {
        return ((threadPool == null) ? 0 : (int) threadPool.getCompletedTaskCount());
    }

    int getTotalThreadCount() {
        return (threads == null) ? 0 : threads.size();
    }

    boolean isTerminated() {
        return threadPool.isTerminated();
    }

    boolean isError() {
        return isError;
    }

    Exception getThreadException() {
        return threadException;
    }

    synchronized void interrupt(final Thread thread, final Exception e) {
        threadException = e;
        isError = true;
        shutdownNow();
        logger.error(thread.getName().concat(" causes an error: ").concat(e.getMessage()), e);
    }

    boolean isCanceled() {
        return isCanceled;
    }

    void cancel() {
        isCanceled = true;
        shutdownNow();
    }

    private void shutdownNow() {
        try {
            threadPool.shutdownNow(); // Cancel currently executing tasks
            // Wait a while for tasks to respond to being cancelled
            if (!threadPool.awaitTermination(60, TimeUnit.SECONDS))
                logger.error("ThreadPool did not terminate");
        } catch (InterruptedException ie) {
            // (Re-)Cancel if current thread also interrupted
            threadPool.shutdownNow();
            // Preserve interrupt status
            Thread.currentThread().interrupt();
        }
    }
}