使qthread作为单身人士消耗大量的CPU负荷

Question

即时通讯尝试在我的项目的不同对象中具有qthread的范围。所以我试图让线程成为一个单身人士。它是一个用作客户端的DBUS接口。

这是我实施的代码。 .H

class ClientDBUSThread : public QThread 
{ 
    Q_OBJECT 

public: 
    static ClientDBUSThread *getInstance(); 

    void messageReceived(QString); 

private: 
    ClientDBUSThread(); 
    static ClientDBUSThread *instance; 
    static QMutex instanceMutex; 
    void run(); 

signals: 
    void signalReceivedInDBUS(QString); 

public Q_SLOTS: 
    void mySlot(QString); 

    void stop(); 

private: 
    DemoIf* client ; 
    QMutex m_mutex; 
    bool m_stop; 

}; 

和.cpp

#include "ClienDBusThread.h" 

#include <QMap> 

ClientDBUSThread *ClientDBUSThread::instance(0); 
QMutex ClientDBUSThread::instanceMutex; 

ClientDBUSThread *ClientDBUSThread::getInstance() 
{ 
    if (!instance) { 
     QMutexLocker instanceMutexLocker(&instanceMutex); 
     if (!instance) { 
      instance = new ClientDBUSThread(); 
     } 
    } 

    return instance; 
} 


ClientDBUSThread::ClientDBUSThread() 
{ 
    m_stop = false; 
    client = new DemoIf("com.nokia.Demo", "/", QDBusConnection::sessionBus(), 0); 
    connect(client, SIGNAL(LateEvent(QString)), this, SLOT(mySlot(QString))); 
    QDBusConnection cnn= client->connection(); 

    qDebug()<<"is the DBUS gets connected:"<<cnn.isConnected(); 

    const QMap<QString, QVariant> hi; 
    client->SayHello("HELLO THERE HOW ARE YOU", hi); 

    client->SayBye(); 
} 

void ClientDBUSThread::run() 
{ 

    while (1) { 

      QMutexLocker locker(&m_mutex); 
      if (m_stop) break; 

    } 
} 

void ClientDBUSThread::stop() 
{ 

    QMutexLocker locker(&m_mutex); 
    m_stop=true; 

    client->SayBye(); 
} 

void ClientDBUSThread::messageReceived(QString message) 
{ 
    const QMap<QString, QVariant> hi; 
    client->SayHello(message, hi); 
} 



void ClientDBUSThread::mySlot(QString data) 
{ 

    emit signalReceivedInDBUS(data); 
} 

而声明等

theDBUSThread = ClientDBUSThread ::的getInstance（）的对象; 这很好，但启动线程

theDBUSThread-> start（）;

CPU负载超过PC的100％。即时消息只在主类中启动线程。剩下的课只是宣布和使用DBUS收到的信号。

Answer 1

只有您的run（）循环代码在线程中执行。如果没有事件循环在触发时运行插槽，您希望代码如何运行其他任何事情？

在这种情况下，您不应该从QThread继承子类。

相反，从QObject派生你的类。

class ClientDBUSThread : public QObject 
{ 
    Q_OBJECT 

public: 
    static ClientDBUSThread *getInstance(); 

    void messageReceived(QString); 

private: 
    ClientDBUSThread(); 
    static ClientDBUSThread *instance; 
    static QThread * thread; 
    static QMutex instanceMutex; 
    //void run(); //removed 

signals: 
    void signalReceivedInDBUS(QString); 

public Q_SLOTS: 
    void startup(); 
    void mySlot(QString); 
    void stop(); 

private: 
    DemoIf* client ; 
    QMutex m_mutex; 
    bool m_stop; 

}; 

在GetInstance（）中与您的主类一起创建一个静态QThread实例。然后移动后者螺纹：

ClientDBUSThread *ClientDBUSThread::getInstance() 
{ 
    if (!instance) { 
     QMutexLocker instanceMutexLocker(&instanceMutex); 
     if (!instance) { 
      //You will need to destroy these somewhere 
      instance = new ClientDBUSThread(); 
      thread = new QThread(); 
      instance->moveToThread(thread); 
      connect(thread, SIGNAL(started()), instance, SLOT(startup())); 
      //the thread is not started yet, you need to thread->start() somewhere 
     } 
    } 

    return instance; 
} 

然后尽你的启动工作不是在构造函数中，但在启动

void ClientDBUSThread::ClientDBUSThread() 
{ 
    //I supposed that last argument of DemoIf constructor 
    //is the pointer to parent. It may be a good idea to parent it with this, 
    //So I replaced 0 by this 
    client = new DemoIf("com.nokia.Demo", "/", QDBusConnection::sessionBus(), this); 
    connect(client, SIGNAL(LateEvent(QString)), this, SLOT(mySlot(QString))); 
} 


void ClientDBUSThread::startup() 
{ 
    m_stop = false; 
    QDBusConnection cnn= client->connection(); 

    qDebug()<<"is the DBUS gets connected:"<<cnn.isConnected(); 

    const QMap<QString, QVariant> hi; 
    client->SayHello("HELLO THERE HOW ARE YOU", hi); 

    client->SayBye(); 
}