/****************************************************************************
**
** Copyright (C) 2013 Digia Plc and/or its subsidiary(-ies).
** Contact: http://www.qt-project.org/legal
**
** 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 Digia Plc 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.
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****************************************************************************/

#include <QtCore>

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

//! [0]
const int DataSize = 100000;

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

QWaitCondition bufferNotEmpty;
QWaitCondition bufferNotFull;
QMutex mutex;
int numUsedBytes = 0;
//! [0]

//! [1]
class Producer : public QThread
//! [1] //! [2]
{
public:
    Producer(QObject *parent = NULL) : QThread(parent)
    {
    }

    void run() Q_DECL_OVERRIDE
    {
        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();
        }
    }
};
//! [2]

//! [3]
class Consumer : public QThread
//! [3] //! [4]
{
    Q_OBJECT
public:
    Consumer(QObject *parent = NULL) : QThread(parent)
    {
    }

    void run() Q_DECL_OVERRIDE
    {
        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");
    }

signals:
    void stringConsumed(const QString &text);
};
//! [4]


//! [5]
int main(int argc, char *argv[])
//! [5] //! [6]
{
    QCoreApplication app(argc, argv);
    Producer producer;
    Consumer consumer;
    producer.start();
    consumer.start();
    producer.wait();
    consumer.wait();
    return 0;
}
//! [6]

#include "waitconditions.moc"
