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

semaphores.cpp Example File
threads/semaphores/semaphores.cpp

/****************************************************************************
**
** Copyright (C) 2005-2006 Trolltech ASA. All rights reserved.
**
** This file is part of the example classes of the Qt Toolkit.
**
** Licensees holding valid Qt Preview licenses may use this file in
** accordance with the Qt Preview License Agreement provided with the
** Software.
**
** See http://www.trolltech.com/pricing.html or email sales@trolltech.com for
** information about Qt Commercial License Agreements.
**
** Contact info@trolltech.com if any conditions of this licensing are
** not clear to you.
**
** This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
** WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
**
****************************************************************************/

#include <QtCore>

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

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

QSemaphore freeBytes(BufferSize);
QSemaphore usedBytes;

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) {
        freeBytes.acquire();
        buffer[i % BufferSize] = "ACGT"[(int)qrand() % 4];
        usedBytes.release();
    }
}

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

void Consumer::run()
{
    for (int i = 0; i < DataSize; ++i) {
        usedBytes.acquire();
        fprintf(stderr, "%c", buffer[i % BufferSize]);
        freeBytes.release();
    }
    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 © 2006 Trolltech Trademarks
Qt 4.2.0-rc1