QT的qsemaphore编程

使用semaphore进行线程间的同步比使用mutex高级之处就在于其可以同时管理好几个同类资源。

源代码如下：

.h文件

/****************************************************************************
** Form interface generated from reading ui file 'newprojectdialog.ui'
**
** Created: 鏄熸湡鍥?涓夋湀 6 15:05:25 2008
**      by: The User Interface Compiler ($Id: qt/main.cpp   3.2.1   edited May 19 14:22 $)
**
** WARNING! All changes made in this file will be lost!
****************************************************************************/

#ifndef NEWPROJECTDIALOG_H
#define NEWPROJECTDIALOG_H

#include
#include
#include
#include
#include

class QVBoxLayout;
class QHBoxLayout;
class QGridLayout;
class QTextEdit;
class QLineEdit;
class QPushButton;

class univerData
{
public:
    static int in_num;
 static int out_num;
 static QString str;
 //static char buffer[10];
 static QSemaphore freeSpace;
 static QSemaphore usedSpace;
};

class produceThread : public QThread
{
public:
    Thread();
 
 void run();
};

class consumeThread : public QThread
{
public:
    Thread();

 void run();
};

class NewProjectDialog : public QDialog
{
    Q_OBJECT

public:
    NewProjectDialog( QWidget* parent = 0, const char* name = 0, bool modal = FALSE, WFlags fl = 0 );
    ~NewProjectDialog();

    QTextEdit* textEdit1;
    QLineEdit* lineEdit1;
    QPushButton* pushButton6;
    QPushButton* pushButton7;
    QPushButton* pushButton5;
 produceThread pp;
 consumeThread cc;

public slots:
    virtual void produce();
    virtual void consume();

protected:

protected slots:
    virtual void languageChange();

};

#endif // NEWPROJECTDIALOG_H

.cpp文件如下：

/****************************************************************************
** Form implementation generated from reading ui file 'newprojectdialog.ui'
**
** Created: 鏄熸湡鍥?涓夋湀 6 15:05:27 2008
**      by: The User Interface Compiler ($Id: qt/main.cpp   3.2.1   edited May 19 14:22 $)
**
** WARNING! All changes made in this file will be lost!
****************************************************************************/

#include "newprojectdialog.h"

#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include

/*
 *  Constructs a NewProjectDialog as a child of 'parent', with the
 *  name 'name' and widget flags set to 'f'.
 *
 *  The dialog will by default be modeless, unless you set 'modal' to
 *  TRUE to construct a modal dialog.
 */
QString buffer[10];

QSemaphore univerData::freeSpace(10);
QSemaphore univerData::usedSpace(10);
QString univerData::str="hello";
int univerData::in_num=0;
int univerData::out_num=0;

void produceThread::run()
{
   int in;
   univerData::freeSpace--;
   in=univerData::in_num%10;
   buffer[in]="hello";
   univerData::usedSpace++;
}

void consumeThread::run()
{
   int out;
   univerData::usedSpace--;
   out=univerData::out_num%10;

   univerData::freeSpace++;
}

NewProjectDialog::NewProjectDialog( QWidget* parent, const char* name, bool modal, WFlags fl )
    : QDialog( parent, name, modal, fl )
{
    if ( !name )
 setName( "NewProjectDialog" );
    setSizeGripEnabled( TRUE );

    textEdit1 = new QTextEdit( this, "textEdit1" );
    textEdit1->setGeometry( QRect( 20, 30, 371, 201 ) );

    lineEdit1 = new QLineEdit( this, "lineEdit1" );
    lineEdit1->setGeometry( QRect( 20, 260, 371, 61 ) );

    pushButton6 = new QPushButton( this, "pushButton6" );
    pushButton6->setGeometry( QRect( 430, 160, 110, 41 ) );

    pushButton7 = new QPushButton( this, "pushButton7" );
    pushButton7->setGeometry( QRect( 430, 270, 111, 41 ) );

    pushButton5 = new QPushButton( this, "pushButton5" );
    pushButton5->setGeometry( QRect( 430, 50, 110, 40 ) );
    languageChange();
    resize( QSize(585, 363).expandedTo(minimumSizeHint()) );
    clearWState( WState_Polished );

   

    // signals and slots connections
    connect( pushButton5, SIGNAL( clicked() ), this, SLOT( produce() ) );
 connect( pushButton6, SIGNAL( clicked() ), this, SLOT( consume() ) );
    connect( pushButton7, SIGNAL( clicked() ), this, SLOT( close() ) );
}

/*
 *  Destroys the object and frees any allocated resources
 */
NewProjectDialog::~NewProjectDialog()
{
    // no need to delete child widgets, Qt does it all for us
}

/*
 *  Sets the strings of the subwidgets using the current
 *  language.
 */
void NewProjectDialog::languageChange()
{
    setCaption( tr( "NewProject" ) );
    pushButton6->setText( tr( "pushButton6" ) );
    pushButton7->setText( tr( "pushButton7" ) );
    pushButton5->setText( tr( "pushButton5" ) );
}

void NewProjectDialog::produce()
{
   
    pp.start();
}

void NewProjectDialog::consume()
{
    lineEdit1->setText(buffer[0]);
    cc.start();
}

此程序主要实现功能如下，生产者向缓冲区中存入数据，消费者从缓冲区中取出数据

需要注意的是在linux下qt不能直接在全局变量区处声明全局变量，但在win下却可以直接在全局变量区处声明全局变量。

还有一点不同的是在linux下可以直接在头文件中定义类中静态变量的值，但如果在win下的qt中直接定义全局变量的值则会提示错误。