Subscriber.java

Go to the documentation of this file.

/*
 * Software License Agreement (BSD License)
 *
 *  Copyright (c) 2008, Willow Garage, Inc.
 *  All rights reserved.
 *
 *  Redistribution and use in source and binary forms, with or without
 *  modification, are permitted provided that the following conditions
 *  are met:
 *
 *   * Redistributions of source code must retain the above copyright
 *     notice, this list of conditions and the following disclaimer.
 *   * Redistributions in binary form must reproduce the above
 *     copyright notice, this list of conditions and the following
 *     disclaimer in the documentation and/or other materials provided
 *     with the distribution.
 *   * Neither the name of Willow Garage, Inc. nor the names of its
 *     contributors may be used to endorse or promote products derived
 *     from this software without specific prior written permission.
 *
 *  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 *  "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 *  LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
 *  FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
 *  COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
 *  INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
 *  BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 *  LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
 *  CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 *  LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
 *  ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 *  POSSIBILITY OF SUCH DAMAGE.
 */

// author: Jason Wolfe



package ros;

import java.util.Queue;
import java.util.concurrent.ConcurrentLinkedQueue;

import ros.communication.Message;

public interface Subscriber<M extends Message> {
        public String getTopic();
        public void shutdown();
        public boolean isValid();
        
        public static interface Callback<M extends Message> {
                // request must be treated as constant, since it may be concurrently accessed by other threads..
                public void call(M request);
        }
        
        public static class QueueingCallback<M extends Message> implements Callback<M> {
                private Queue<M> queue;
                
                public QueueingCallback() {
                        queue = new ConcurrentLinkedQueue<M>();
                }
                
                @SuppressWarnings({ "unchecked"})
                public void call(M request) {
                        synchronized(queue) {
                                queue.add((M) request.clone());
                                queue.notify();
                        }
                }
                
                public M pop() throws InterruptedException {
                        synchronized(queue) {
                                while(queue.isEmpty()) {
                                        queue.wait();
                                }
                                return queue.remove();
                        }
                }
                

                public M peek() throws InterruptedException {
                        synchronized(queue) {
                                while(queue.isEmpty()) {
                                        queue.wait();
                                }
                                return queue.peek();
                        }
                }

                public void clear() {
                        synchronized(queue) {
                                queue.clear();
                        }
                }

                
                public boolean isEmpty() {
                        return queue.isEmpty();
                }
                
                public int     size() {
                        return queue.size();
                }
                
        }
}

---

rosjava
Author(s): Jason Wolfe (jawolfe@willowgarage.com), Nicholas Butko (nbutko@cogsci.ucsd.edu), Lorenz Moesenlechner (moesenle@in.tum.de)
autogenerated on Fri Jan 11 09:32:18 2013