Foundations of Qt Development\Chapter12\semaphorethreads\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
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* 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
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* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
*/
#include
#include
#include
#include
const int bufferSize = 20;
QChar buffer[ bufferSize ];
QSemaphore freeSpace( bufferSize );
QSemaphore availableData( 0 );
bool atEnd = false;
class TextProducer : public QThread
{
public:
TextProducer( QString text );
void run();
private:
QString m_text;
};
TextProducer::TextProducer( QString text ) : QThread()
{
m_text = text;
}
void TextProducer::run()
{
for( int i=0; i {
freeSpace.acquire();
buffer[ i % bufferSize ] = m_text.data()[ i ];
if( i == m_text.length()-1 )
atEnd = true;
availableData.release();
}
}
class TextConsumer : public QThread
{
public:
void run();
};
void TextConsumer::run()
{
int i = 0;
while( !atEnd || availableData.available() )
{
availableData.acquire();
qDebug() << buffer[ i ];
i = (i+1) % bufferSize;
freeSpace.release();
}
}
int main( int argc, char **argv )
{
QApplication app( argc, argv );
TextProducer producer( "Lorem ipsum dolor sit amet, "
"consectetuer adipiscing elit. "
"Praesent tortor." );
TextConsumer consumer;
producer.start();
consumer.start();
producer.wait();
consumer.wait();
return 0;
}