qt5base-lts/examples/corelib/threads/waitconditions/waitconditions.cpp
hjk 40a54bf565 Examples: Replace 'Q_DECL_OVERRIDE' by 'override'
Examples should demonstrate best practice, and we can use the keyword
directly nowadays.

Change-Id: I1f122e5caceca17290757ffbaf3d660e7daa9ae4
Reviewed-by: Topi Reiniö <topi.reinio@theqtcompany.com>
2016-06-15 09:32:30 +00:00

148 lines
4.2 KiB
C++

/****************************************************************************
**
** Copyright (C) 2016 The Qt Company Ltd.
** Contact: https://www.qt.io/licensing/
**
** This file is part of the examples of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:BSD$
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** accordance with the commercial license agreement provided with the
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** information use the contact form at https://www.qt.io/contact-us.
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** Alternatively, 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
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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() 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() 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"