fortunethread.cpp Example File

 /****************************************************************************
 **
 ** Copyright (C) 2012 Nokia Corporation and/or its subsidiary(-ies).
 ** Contact: http://www.qt-project.org/
 **
 ** This file is part of the examples of the Qt Toolkit.
 **
 ** $QT_BEGIN_LICENSE:BSD$
 ** You may use this file under the terms of the BSD license as follows:
 **
 ** "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 Nokia Corporation and its Subsidiary(-ies) 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."
 **
 ** $QT_END_LICENSE$
 **
 ****************************************************************************/

 #include <QtNetwork>

 #include "fortunethread.h"

 FortuneThread::FortuneThread(QObject *parent)
     : QThread(parent), quit(false)
 {
 }

 FortuneThread::~FortuneThread()
 {
     mutex.lock();
     quit = true;
     cond.wakeOne();
     mutex.unlock();
     wait();
 }

 void FortuneThread::requestNewFortune(const QString &hostName, quint16 port)
 {
     QMutexLocker locker(&mutex);
     this->hostName = hostName;
     this->port = port;
     if (!isRunning())
         start();
     else
         cond.wakeOne();
 }

 void FortuneThread::run()
 {
     mutex.lock();
     QString serverName = hostName;
     quint16 serverPort = port;
     mutex.unlock();

     while (!quit) {
         const int Timeout = 5 * 1000;

         QTcpSocket socket;
         socket.connectToHost(serverName, serverPort);

         if (!socket.waitForConnected(Timeout)) {
             emit error(socket.error(), socket.errorString());
             return;
         }

         while (socket.bytesAvailable() < (int)sizeof(quint16)) {
             if (!socket.waitForReadyRead(Timeout)) {
                 emit error(socket.error(), socket.errorString());
                 return;
             }
         }

         quint16 blockSize;
         QDataStream in(&socket);
         in.setVersion(QDataStream::Qt_4_0);
         in >> blockSize;

         while (socket.bytesAvailable() < blockSize) {
             if (!socket.waitForReadyRead(Timeout)) {
                 emit error(socket.error(), socket.errorString());
                 return;
             }
         }

         mutex.lock();
         QString fortune;
         in >> fortune;
         emit newFortune(fortune);

         cond.wait(&mutex);
         serverName = hostName;
         serverPort = port;
         mutex.unlock();
     }
 }