Home · All Namespaces · All Classes · Main Classes · Grouped Classes · Modules · Functions

waitconditions.cpp Example File
threads/waitconditions/waitconditions.cpp

 /****************************************************************************
 **
 ** Copyright (C) 2008 Nokia Corporation and/or its subsidiary(-ies).
 ** Contact: Qt Software Information ([email protected])
 **
 ** This file is part of the example classes of the Qt Toolkit.
 **
 ** Commercial Usage
 ** Licensees holding valid Qt Commercial licenses may use this file in
 ** accordance with the Qt Commercial License Agreement provided with the
 ** Software or, alternatively, in accordance with the terms contained in
 ** a written agreement between you and Nokia.
 **
 **
 ** GNU General Public License Usage
 ** Alternatively, this file may be used under the terms of the GNU
 ** General Public License versions 2.0 or 3.0 as published by the Free
 ** Software Foundation and appearing in the file LICENSE.GPL included in
 ** the packaging of this file.  Please review the following information
 ** to ensure GNU General Public Licensing requirements will be met:
 ** http://www.fsf.org/licensing/licenses/info/GPLv2.html and
 ** http://www.gnu.org/copyleft/gpl.html.  In addition, as a special
 ** exception, Nokia gives you certain additional rights. These rights
 ** are described in the Nokia Qt GPL Exception version 1.3, included in
 ** the file GPL_EXCEPTION.txt in this package.
 **
 ** Qt for Windows(R) Licensees
 ** As a special exception, Nokia, as the sole copyright holder for Qt
 ** Designer, grants users of the Qt/Eclipse Integration plug-in the
 ** right for the Qt/Eclipse Integration to link to functionality
 ** provided by Qt Designer and its related libraries.
 **
 ** If you are unsure which license is appropriate for your use, please
 ** contact the sales department at [email protected].
 **
 ****************************************************************************/

 #include <QtCore>

 #include <stdio.h>
 #include <stdlib.h>

 const int DataSize = 100000;
 const int BufferSize = 8192;
 char buffer[BufferSize];

 QWaitCondition bufferNotEmpty;
 QWaitCondition bufferNotFull;
 QMutex mutex;
 int numUsedBytes = 0;

 class Producer : public QThread
 {
 public:
     void run();
 };

 void Producer::run()
 {
     qsrand(QTime(0,0,0).secsTo(QTime::currentTime()));

     for (int i = 0; i < DataSize; ++i) {
         mutex.lock();
         if (numUsedBytes == BufferSize)
             bufferNotFull.wait(&mutex);
         mutex.unlock();

         buffer[i % BufferSize] = "ACGT"[(int)qrand() % 4];

         mutex.lock();
         ++numUsedBytes;
         bufferNotEmpty.wakeAll();
         mutex.unlock();
     }
 }

 class Consumer : public QThread
 {
 public:
     void run();
 };

 void Consumer::run()
 {
     for (int i = 0; i < DataSize; ++i) {
         mutex.lock();
         if (numUsedBytes == 0)
             bufferNotEmpty.wait(&mutex);
         mutex.unlock();

         fprintf(stderr, "%c", buffer[i % BufferSize]);

         mutex.lock();
         --numUsedBytes;
         bufferNotFull.wakeAll();
         mutex.unlock();
     }
     fprintf(stderr, "\n");
 }

 int main(int argc, char *argv[])
 {
     QCoreApplication app(argc, argv);
     Producer producer;
     Consumer consumer;
     producer.start();
     consumer.start();
     producer.wait();
     consumer.wait();
     return 0;
 }


Copyright © 2008 Nokia Trademarks
Qt 4.4.3