Mega Code Archive
Using QReadWriteLock
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Foundations of Qt Development\Chapter12\readwritethreads\main.cpp
/*
* Copyright (c) 2006-2007, Johan Thelin
*
* All rights reserved.
*
* 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 APress nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
*/
#include <QApplication>
#include <QThread>
#include <QMessageBox>
#include <QReadWriteLock>
#include <QtDebug>
class TextDevice
{
public:
TextDevice();
void increase();
void write( QString );
private:
int count;
QReadWriteLock lock;
};
TextDevice::TextDevice()
{
count = 0;
}
void TextDevice::increase()
{
QWriteLocker locker( &lock );
count++;
}
void TextDevice::write( QString text )
{
QReadLocker locker( &lock );
qDebug() << QString( "Call %1: %2" ).arg( count ).arg( text );
}
bool stopThreads = false;
class IncreaseThread : public QThread
{
public:
IncreaseThread( TextDevice *device );
void run();
private:
TextDevice *m_device;
};
IncreaseThread::IncreaseThread( TextDevice *device ) : QThread()
{
m_device = device;
}
void IncreaseThread::run()
{
while( !stopThreads )
{
msleep( 1200 );
m_device->increase();
}
}
class TextThread : public QThread
{
public:
TextThread( QString text, TextDevice *m_device );
void run();
private:
QString m_text;
TextDevice *m_device;
};
TextThread::TextThread( QString text, TextDevice *device ) : QThread()
{
m_text = text;
m_device = device;
}
void TextThread::run()
{
while( !stopThreads )
{
m_device->write( m_text );
sleep( 1 );
}
}
int main( int argc, char **argv )
{
QApplication app( argc, argv );
TextDevice device;
IncreaseThread inc( &device );
TextThread foo( "Foo", &device ), bar( "Bar", &device );
foo.start();
bar.start();
inc.start();
QMessageBox::information( 0, "Threading", "Close me to stop!" );
stopThreads = true;
foo.wait();
bar.wait();
inc.wait();
return 0;
}
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