Tomcat example source code file (MasterSlaveWorkerThread.java)

This example Tomcat source code file (MasterSlaveWorkerThread.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Java - Tomcat tags/keywords

interruptedexception, interruptedexception, masterslaveworkerthread, net, network, object, object, pooltcpendpoint, runnable, socket, socket, string, tcpconnection, tcpconnection, thread, threadwithattributes

The Tomcat MasterSlaveWorkerThread.java source code

/*
 *  Licensed to the Apache Software Foundation (ASF) under one or more
 *  contributor license agreements.  See the NOTICE file distributed with
 *  this work for additional information regarding copyright ownership.
 *  The ASF licenses this file to You under the Apache License, Version 2.0
 *  (the "License"); you may not use this file except in compliance with
 *  the License.  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 *  Unless required by applicable law or agreed to in writing, software
 *  distributed under the License is distributed on an "AS IS" BASIS,
 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  See the License for the specific language governing permissions and
 *  limitations under the License.
 */

package org.apache.tomcat.util.net;

import java.net.Socket;

import org.apache.tomcat.util.threads.ThreadWithAttributes;

/**
 * Regular master slave thread pool. Slave threads will wait for work.
 */
class MasterSlaveWorkerThread implements Runnable {

    protected PoolTcpEndpoint endpoint;
    protected String threadName;
    protected boolean stopped = false;
    private Object threadSync = new Object();
    private Thread thread = null;
    private boolean available = false;
    private Socket socket = null;
    private TcpConnection con = new TcpConnection();
    private Object[] threadData = null;

    
    public MasterSlaveWorkerThread(PoolTcpEndpoint endpoint, String threadName) {
        this.endpoint = endpoint;
        this.threadName = threadName;
    }


    /**
     * Process an incoming TCP/IP connection on the specified socket.  Any
     * exception that occurs during processing must be logged and swallowed.
     * <b>NOTE:  This method is called from our Connector's thread.  We
     * must assign it to our own thread so that multiple simultaneous
     * requests can be handled.
     *
     * @param socket TCP socket to process
     */
    synchronized void assign(Socket socket) {

        // Wait for the Processor to get the previous Socket
        while (available) {
            try {
                wait();
            } catch (InterruptedException e) {
            }
        }

        // Store the newly available Socket and notify our thread
        this.socket = socket;
        available = true;
        notifyAll();

    }

    
    /**
     * Await a newly assigned Socket from our Connector, or <code>null
     * if we are supposed to shut down.
     */
    private synchronized Socket await() {

        // Wait for the Connector to provide a new Socket
        while (!available) {
            try {
                wait();
            } catch (InterruptedException e) {
            }
        }

        // Notify the Connector that we have received this Socket
        Socket socket = this.socket;
        available = false;
        notifyAll();

        return (socket);

    }



    /**
     * The background thread that listens for incoming TCP/IP connections and
     * hands them off to an appropriate processor.
     */
    public void run() {

        // Process requests until we receive a shutdown signal
        while (!stopped) {

            // Wait for the next socket to be assigned
            Socket socket = await();
            if (socket == null)
                continue;

            // Process the request from this socket
            endpoint.processSocket(socket, con, threadData);

            // Finish up this request
            endpoint.recycleWorkerThread(this);

        }

        // Tell threadStop() we have shut ourselves down successfully
        synchronized (threadSync) {
            threadSync.notifyAll();
        }

    }


    /**
     * Start the background processing thread.
     */
    public void start() {
        threadData = endpoint.getConnectionHandler().init();
        thread = new ThreadWithAttributes(null, this);
        thread.setName(threadName);
        thread.setDaemon(true);
        thread.start();
    }


    /**
     * Stop the background processing thread.
     */
    public void stop() {
        stopped = true;
        assign(null);
        thread = null;
        threadData = null;
    }


}