semaphores.cpp

qt-x11-opensource-src-4.1.4.tar.gz源码

/****************************************************************************
**
** Copyright (C) 2005-2006 Trolltech ASA. All rights reserved.
**
** This file is part of the example classes of the Qt Toolkit.
**
** This file may be used under the terms of the GNU General Public
** License version 2.0 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.trolltech.com/products/qt/opensource.html
**
** If you are unsure which license is appropriate for your use, please
** review the following information:
** http://www.trolltech.com/products/qt/licensing.html or contact the
** sales department at [e-mail].
**
** This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
** WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
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****************************************************************************/

#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()
{
    for (int i = 0; i < DataSize; ++i) {
        freeBytes.acquire();
        buffer[i % BufferSize] = "ACGT"[(int)rand() % 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;
}