com.bigdata.rdf.graph.impl.DaemonThreadFactory Maven / Gradle / Ivy

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/**

Copyright (C) SYSTAP, LLC DBA Blazegraph 2006-2016.  All rights reserved.

Contact:
     SYSTAP, LLC DBA Blazegraph
     2501 Calvert ST NW #106
     Washington, DC 20008
     [email protected]

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; version 2 of the License.

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, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
*/
package com.bigdata.rdf.graph.impl;

import java.util.concurrent.Executors;
import java.util.concurrent.ThreadFactory;

/**
 * A thread factory that configures the thread as a daemon thread.
 * 
 * @author Bryan Thompson
 * @version $Id: DaemonThreadFactory.java 5824 2011-12-29 20:52:02Z thompsonbry $
 */
/*
 * Note: This is a clone of the same-named class in the bigdata module. The
 * clone exists to have it under the Apache 2 license requiring the creation of
 * a bigdata-commons module.
 */
class DaemonThreadFactory implements ThreadFactory {

    final private ThreadFactory delegate;
    final private String basename; // MAY be null.
    private int counter = 0; // used iff basename was given.

    private static ThreadFactory _default = new DaemonThreadFactory();
    
    /**
     * Returns an instance based on {@link Executors#defaultThreadFactory()}
     * that configures the thread for daemon mode.
     */
    final public static ThreadFactory defaultThreadFactory() {

        return _default;
        
    }
    
    /**
     * Uses {@link Executors#defaultThreadFactory()} as the delegate.
     */
    public DaemonThreadFactory() {
        
        this( Executors.defaultThreadFactory(), null/*basename*/ );
        
    }
    
    public DaemonThreadFactory(String basename) {

        this(Executors.defaultThreadFactory(), basename);

    }
    
    /**
     * Uses the specified delegate {@link ThreadFactory}.
     * 
     * @param delegate
     *            The delegate thread factory that is responsible for creating
     *            the threads.
     * @param basename
     *            Optional prefix that will be used to assign names to the
     *            generated threads.
     */
    public DaemonThreadFactory(final ThreadFactory delegate,
            final String basename) {
        
        if (delegate == null)
            throw new IllegalArgumentException();
        
        this.delegate = delegate;
        
        this.basename = basename;
        
    }
    
    public Thread newThread(final Runnable r) {
        
        final Thread t = delegate.newThread( r );
 
        if (basename != null) {
         
            counter++;
            
            t.setName(basename + counter);
            
        }
        
        t.setDaemon(true);
        
//        System.err.println("new thread: "+t.getName()+", id="+t.getId());
        
        return t;
        
    }

}