Qt:单实例应用程序保护的最佳实践

Qt: Best practice for a single instance app protection(Qt:单实例应用程序保护的最佳实践)
本文介绍了Qt:单实例应用程序保护的最佳实践的处理方法,对大家解决问题具有一定的参考价值,需要的朋友们下面随着跟版网的小编来一起学习吧!

问题描述

QSingleApplication?QMutex?QSharedMemory?我正在寻找可以在 Windows、OSX 和 Linux (Ubuntu) 中顺利运行的东西.使用 Qt 4.7.1

QSingleApplication? QMutex? QSharedMemory? I'm looking for something that will work smoothly in Windows, OSX and Linux (Ubuntu). Using Qt 4.7.1

推荐答案

简单的解决方案,满足您的需求.没有网络依赖(如 QtSingleApplication)并且没有任何开销.

Simple solution, that does what you want. Without network dependency (as QtSingleApplication) and without any overhead.

用法:

int main()
{
    RunGuard guard( "some_random_key" );
    if ( !guard.tryToRun() )
        return 0;

    QAppplication a(/*...*/);
    // ...
}

RunGuard.h

#ifndef RUNGUARD_H
#define RUNGUARD_H

#include <QObject>
#include <QSharedMemory>
#include <QSystemSemaphore>


class RunGuard
{

public:
    RunGuard( const QString& key );
    ~RunGuard();

    bool isAnotherRunning();
    bool tryToRun();
    void release();

private:
    const QString key;
    const QString memLockKey;
    const QString sharedmemKey;

    QSharedMemory sharedMem;
    QSystemSemaphore memLock;

    Q_DISABLE_COPY( RunGuard )
};


#endif // RUNGUARD_H

RunGuard.cpp

RunGuard.cpp

#include "RunGuard.h"

#include <QCryptographicHash>


namespace
{

QString generateKeyHash( const QString& key, const QString& salt )
{
    QByteArray data;

    data.append( key.toUtf8() );
    data.append( salt.toUtf8() );
    data = QCryptographicHash::hash( data, QCryptographicHash::Sha1 ).toHex();

    return data;
}

}


RunGuard::RunGuard( const QString& key )
    : key( key )
    , memLockKey( generateKeyHash( key, "_memLockKey" ) )
    , sharedmemKey( generateKeyHash( key, "_sharedmemKey" ) )
    , sharedMem( sharedmemKey )
    , memLock( memLockKey, 1 )
{
    memLock.acquire();
    {
        QSharedMemory fix( sharedmemKey );    // Fix for *nix: http://habrahabr.ru/post/173281/
        fix.attach();
    }
    memLock.release();
}

RunGuard::~RunGuard()
{
    release();
}

bool RunGuard::isAnotherRunning()
{
    if ( sharedMem.isAttached() )
        return false;

    memLock.acquire();
    const bool isRunning = sharedMem.attach();
    if ( isRunning )
        sharedMem.detach();
    memLock.release();

    return isRunning;
}

bool RunGuard::tryToRun()
{
    if ( isAnotherRunning() )   // Extra check
        return false;

    memLock.acquire();
    const bool result = sharedMem.create( sizeof( quint64 ) );
    memLock.release();
    if ( !result )
    {
        release();
        return false;
    }

    return true;
}

void RunGuard::release()
{
    memLock.acquire();
    if ( sharedMem.isAttached() )
        sharedMem.detach();
    memLock.release();
}

这篇关于Qt:单实例应用程序保护的最佳实践的文章就介绍到这了,希望我们推荐的答案对大家有所帮助,也希望大家多多支持跟版网!

本站部分内容来源互联网,如果有图片或者内容侵犯您的权益请联系我们删除!

相关文档推荐

Is it possible to connect a signal to a static slot without a receiver instance?(是否可以在没有接收器实例的情况下将信号连接到静态插槽?)
how to restart my own qt application?(如何重新启动我自己的 qt 应用程序?)
Where in Qt Creator do I pass arguments to a compiler?(在 Qt Creator 中,我在哪里将参数传递给编译器?)
Using a Qt-based DLL in a non-Qt application(在非 Qt 应用程序中使用基于 Qt 的 DLL)
Configuring the GCC compiler switches in Qt, QtCreator, and QMake(在 Qt、QtCreator 和 QMake 中配置 GCC 编译器开关)
Difference between creating object with () or without(使用 () 或不使用 () 创建对象的区别)