多线程读者写者问题--用QT实现

先把代码贴上来，有时间再整理吧。。因为工作中用Qt，所以用Qt实现的。。。。刚上班，，忙！

三种方法，读者优先，写者优先和公平竞争。。

读者优先

#include <QCoreApplication>

#include <QThread>

#include <iostream>

#include <QMutex>

#include <QTime>

#include <QtGlobal>

using namespace std;

int buffer;//临界资源

QMutex bMutex;

class Reader:public QThread{

private:

    static int readerCount;

    static QMutex rdcnMutex;

    static QMutex printMutex;

public:

    void read(){

        cout<<"读者读出："<<buffer<<endl;

    }

protected:

    void run(){

        rdcnMutex.lock();

        if(readerCount == ){

            bMutex.lock();

        }

        readerCount++;

        rdcnMutex.unlock();

        printMutex.lock();

        sleep();

        read();

        printMutex.unlock();

        rdcnMutex.lock();

        readerCount--;

        if(readerCount == ){

            bMutex.unlock();

        }

        rdcnMutex.unlock();

    }

};

int Reader::readerCount = ;

QMutex Reader::rdcnMutex;

QMutex Reader::printMutex;

class Writer:public QThread{

public:

    void write(){

        qsrand(QTime(,,).secsTo(QTime::currentTime()));

        buffer = qrand() % ;

        cout<<"写者写入："<<buffer<<endl;

    }

protected:

    void run(){

        bMutex.lock();

        sleep();

        write();

        bMutex.unlock();

    }

};

int main(int argc, char *argv[])

{

    QCoreApplication a(argc, argv);

    buffer = -;

    const int count = ;

    Writer writer[count];

    Reader reader[count];

    for(int i = ; i < count; i++ ){

        writer[i].start();

        reader[i].start();

    }

    for(int i = ; i < count; i++ ){

        writer[i].wait();

        reader[i].wait();

    }

    return a.exec();

}

写者优先：

#include <QCoreApplication>

#include <QMutex>

#include <QtGlobal>

#include <QThread>

#include <iostream>

#include <QtGlobal>

#include <QTime>

using namespace std;

int buffer;//临界资源

QMutex bMutex;

QMutex queueMutex;

class Reader: public QThread{

private:

    static int readerCount;

    static QMutex rdcnMutex;

    static QMutex printMutex;

public:

    void read(){

        printMutex.lock();

        cout<<"读者读出："<<buffer<<endl;

        printMutex.unlock();

    }

protected:

    void run(){

        queueMutex.lock();

        rdcnMutex.lock();

        if(readerCount == ){

            bMutex.lock();

        }

        readerCount++;

        rdcnMutex.unlock();

        queueMutex.unlock();

        sleep();

        read();

        rdcnMutex.lock();

        readerCount--;

        if(readerCount == ){

            bMutex.unlock();

        }

        rdcnMutex.unlock();

    }

};

int Reader::readerCount = ;

QMutex Reader::rdcnMutex;

QMutex Reader::printMutex;

class Writer: public QThread{

private:

    static int writerCount;

    static QMutex wtcnMutex;

public:

    void write(){

        qsrand(QTime(,,).secsTo(QTime::currentTime()));

        buffer = qrand() % ;

        cout<<"写者写入："<<buffer<<endl;

    }

protected:

    void run(){

        wtcnMutex.lock();

        if(writerCount == ){

            queueMutex.lock();

        }

        writerCount++;

        wtcnMutex.unlock();

        bMutex.lock();

        sleep();

        write();

        bMutex.unlock();

        wtcnMutex.lock();

        writerCount--;

        if(writerCount == ){

            queueMutex.unlock();

        }

        wtcnMutex.unlock();

    }

};

int Writer::writerCount = ;

QMutex Writer::wtcnMutex;

int main(int argc, char *argv[])

{

    QCoreApplication a(argc, argv);

    buffer = -;

    const int count = ;

    Writer writer[count];

    Reader reader[count];

    for(int i = ; i < count; i++ ){

        writer[i].start();

        reader[i].start();

    }

    for(int i = ; i < count; i++ ){

        writer[i].wait();

        reader[i].wait();

    }

    return a.exec();

}

公平竞争

#include <QCoreApplication>

#include <QMutex>

#include <QtGlobal>

#include <QThread>

#include <iostream>

#include <QtGlobal>

#include <QTime>

using namespace std;

int buffer;//临界资源

QMutex bMutex;

QMutex queueMutex;

class Reader: public QThread{

private:

    static int readerCount;

    static QMutex rdcnMutex;

    static QMutex printMutex;

public:

    void read(){

        printMutex.lock();

        cout<<"读者读出："<<buffer<<endl;

        printMutex.unlock();

    }

protected:

    void run(){

        queueMutex.lock();

        rdcnMutex.lock();

        if(readerCount == ){

            bMutex.lock();

        }

        readerCount++;

        rdcnMutex.unlock();

        queueMutex.unlock();

        sleep();

        read();

        rdcnMutex.lock();

        readerCount--;

        if(readerCount == ){

            bMutex.unlock();

        }

        rdcnMutex.unlock();

    }

};

int Reader::readerCount = ;

QMutex Reader::rdcnMutex;

QMutex Reader::printMutex;

class Writer: public QThread{

private:

public:

    void write(){

        qsrand(QTime(,,).secsTo(QTime::currentTime()));

        buffer = qrand() % ;

        cout<<"写者写入："<<buffer<<endl;

    }

protected:

    void run(){

        queueMutex.lock();

        bMutex.lock();

        queueMutex.unlock();

        sleep();

        write();

        bMutex.unlock();

    }

};

int main(int argc, char *argv[])

{

    QCoreApplication a(argc, argv);

    buffer = -;

    const int count = ;

    Writer writer[count];

    Reader reader[count];

    for(int i = ; i < count; i++ ){

        writer[i].start();

        reader[i].start();

    }

    for(int i = ; i < count; i++ ){

        writer[i].wait();

        reader[i].wait();

    }

    return a.exec();

}