/* * Copyright (c) 1996, Oracle and/or its affiliates. All rights reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 only, as * published by the Free Software Foundation.  Oracle designates this * particular file as subject to the "Classpath" exception as provided * by Oracle in the LICENSE file that accompanied this code. * * This code 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 * version 2 for more details (a copy is included in the LICENSE file that * accompanied this code). * * You should have received a copy of the GNU General Public License version * 2 along with this work; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. */ package sun.misc; /** * The request processor allows functors (Request instances) to be created * in arbitrary threads, and to be posted for execution in a non-restricted * thread. * * @author      Steven B. Byrne */  public class RequestProcessor implements Runnable {     private static Queue requestQueue;    private static Thread dispatcher;     /**     * Queues a Request instance for execution by the request procesor     * thread.     */    public static void postRequest(Request req) {        lazyInitialize();        requestQueue.enqueue(req);    }     /**     * Process requests as they are queued.     */    public void run() {        lazyInitialize();        while (true) {            try {                Object obj = requestQueue.dequeue();                if (obj instanceof Request) { // ignore bogons                    Request req = (Request)obj;                    try {                        req.execute();                    } catch (Throwable t) {                        // do nothing at the moment...maybe report an error                        // in the future                    }                }            } catch (InterruptedException e) {                // do nothing at the present time.            }        }    }      /**     * This method initiates the request processor thread.  It is safe     * to call it after the thread has been started.  It provides a way for     * clients to deliberately control the context in which the request     * processor thread is created     */    public static synchronized void startProcessing() {        if (dispatcher == null) {            dispatcher = new Thread(new RequestProcessor(), "Request Processor");            dispatcher.setPriority(Thread.NORM_PRIORITY + 2);            dispatcher.start();        }    }      /**     * This method performs lazy initialization.     */    private static synchronized void lazyInitialize() {        if (requestQueue == null) {            requestQueue = new Queue();        }    } }