- Qt 5.5
- Qt Network
- Blocking Fortune Client Example
- fortunethread.cpp Example File
- Qt 5.5.1 Reference Documentation

# fortunethread.cpp Example File

blockingfortuneclient/fortunethread.cpp

    /****************************************************************************
    **
    ** Copyright (C) 2015 The Qt Company Ltd.
    ** Contact: http://www.qt.io/licensing/
    **
    ** 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 The Qt Company Ltd 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();
        }
    }