/*
 * JBoss, Home of Professional Open Source
 * Copyright 2009 Red Hat Inc. and/or its affiliates and other
 * contributors as indicated by the @author tags. All rights reserved.
 * See the copyright.txt in the distribution for a full listing of
 * individual contributors.
 *
 * This is free software; you can redistribute it and/or modify it
 * under the terms of the GNU Lesser General Public License as
 * published by the Free Software Foundation; either version 2.1 of
 * the License, or (at your option) any later version.
 *
 * This software 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
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this software; if not, write to the Free
 * Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
 * 02110-1301 USA, or see the FSF site: http://www.fsf.org.
 */
package org.infinispan.util.concurrent;

import java.util.concurrent.ExecutorService;
import java.util.concurrent.LinkedBlockingQueue;
import java.util.concurrent.ThreadFactory;
import java.util.concurrent.ThreadPoolExecutor;
import java.util.concurrent.TimeUnit;

/**
 * Similar to JDK {@link java.util.concurrent.Executors} except that the factory methods here allow you to specify the
 * size of the blocking queue that backs the executor.
 *
 * @author Manik Surtani (<a href="mailto:manik AT jboss DOT org">manik AT jboss DOT org</a>)
 * @since 4.0
 */
public class BoundedExecutors {
   /**
    * Creates a thread pool that reuses a fixed set of threads operating off a shared bounded queue. If any thread
    * terminates due to a failure during execution prior to shutdown, a new one will take its place if needed to execute
    * subsequent tasks.
    *
    * @param nThreads         the number of threads in the pool
    * @param boundedQueueSize size of the bounded queue
    * @return the newly created thread pool
    */
   public static ExecutorService newFixedThreadPool(int nThreads, int boundedQueueSize) {
      return new ThreadPoolExecutor(nThreads, nThreads,
                                    0L, TimeUnit.MILLISECONDS,
                                    new LinkedBlockingQueue<Runnable>(boundedQueueSize));
   }

   /**
    * Creates a thread pool that reuses a fixed set of threads operating off a shared bounded queue, using the provided
    * ThreadFactory to create new threads when needed.
    *
    * @param nThreads         the number of threads in the pool
    * @param threadFactory    the factory to use when creating new threads
    * @param boundedQueueSize size of the bounded queue
    * @return the newly created thread pool
    */
   public static ExecutorService newFixedThreadPool(int nThreads, ThreadFactory threadFactory, int boundedQueueSize) {
      return new ThreadPoolExecutor(nThreads, nThreads,
                                    0L, TimeUnit.MILLISECONDS,
                                    new LinkedBlockingQueue<Runnable>(boundedQueueSize),
                                    threadFactory);
   }
}