/* -*- tab-width: 4 -*-
*
* Electric(tm) VLSI Design System
*
* File: MultiThreadedRandomizer.java
*
* Copyright (c) 2010, Oracle and/or its affiliates. All rights reserved.
*
* Electric(tm) 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; either version 3 of the License, or
* (at your option) any later version.
*
* Electric(tm) 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 Electric(tm); see the file COPYING. If not, write to
* the Free Software Foundation, Inc., 59 Temple Place, Suite 330,
* Boston, Mass 02111-1307, USA.
*/
package com.sun.electric.tool.util.concurrent.runtime;
import java.util.Random;
// FIXME this randomizer is not workable at all with two thread pools
/**
* In multi-threaded environment it is important for randomizations that each
* thread has its own randomizer. Each randomizer has its own start seed. So
* best distribution is possible. This class provides a multi-threaded
* randomizer. Each thread gets its own.
*
* @author Felix Schmidt
*
*/
public class MultiThreadedRandomizer {
private int numOfCores;
private ThreadLocal<Random> randomizer;
/**
* Constructor
*
* @param numOfCores
*/
public MultiThreadedRandomizer(int numOfCores) {
this.numOfCores = numOfCores;
randomizer = new ThreadLocal<Random>();
}
/**
* This function returns a randomizer, which is according to the current
* thread. If there is no randomizer available return a new.
*
* @return a assigned randomizer or a new one if no available
*/
public Random getRandomizer() {
if(randomizer.get() == null) {
randomizer.set(new Random(System.currentTimeMillis()));
}
return randomizer.get();
}
}