001    /**
002     * Copyright (c) 2000-2011 Liferay, Inc. All rights reserved.
003     *
004     * This library is free software; you can redistribute it and/or modify it under
005     * the terms of the GNU Lesser General Public License as published by the Free
006     * Software Foundation; either version 2.1 of the License, or (at your option)
007     * any later version.
008     *
009     * This library is distributed in the hope that it will be useful, but WITHOUT
010     * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
011     * FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more
012     * details.
013     */
014    
015    package com.liferay.portal.kernel.util;
016    
017    /**
018     * @author Tina Tian
019     */
020    public class ThreadUtil {
021    
022            public static Thread[] getThreads() {
023                    Thread currentThread = Thread.currentThread();
024    
025                    ThreadGroup threadGroup = currentThread.getThreadGroup( );
026    
027                    while (threadGroup.getParent() != null) {
028                            threadGroup = threadGroup.getParent();
029                    }
030    
031                    int threadCountGuess = threadGroup.activeCount();
032    
033                    Thread[] threads = new Thread[threadCountGuess];
034    
035                    int threadCountActual = threadGroup.enumerate(threads);
036    
037                    while (threadCountActual == threadCountGuess) {
038                            threadCountGuess *= 2;
039    
040                            threads = new Thread[threadCountGuess];
041    
042                            threadCountActual = threadGroup.enumerate(threads);
043                    }
044    
045                    return threads;
046            }
047    
048    }