CPU consumption

[valgaba]

Curious phenomenon in CPU consumption.
In the first code
CPU consumption is zero

Timer= new QTimer(this);
    connect(Timer, SIGNAL(timeout()), this, SLOT(Update())); // temporizaor horario
Timer->start(10);

Timer= new QTimer(this);
    connect(Timer, SIGNAL(timeout()), this, SLOT(Update())); // temporizaor horario
Timer->start(10);

To copy to clipboard, switch view to plain text mode 

void StreamRender::Update(){
 
 
     QTimer::singleShot(30, this, SLOT(render())); 
 
    if (isFinal())
    {
         //if(Timer->isActive ())
        // {
            Timer->stop();
             emit  Finish();
        // }
     }
 
 
 
}

void StreamRender::Update(){


     QTimer::singleShot(30, this, SLOT(render())); 

    if (isFinal())
    {
         //if(Timer->isActive ())
        // {
            Timer->stop();
             emit  Finish();
        // }
     }

    

}

To copy to clipboard, switch view to plain text mode 

second code
CPU consumption of 10

void StreamRender::Update(){
 
 
 
    if (isFinal())
    {
         //if(Timer->isActive ())
        // {
            Timer->stop();
             emit  Finish();
        // }
     }
 
     render();
 
}

void StreamRender::Update(){


    
    if (isFinal())
    {
         //if(Timer->isActive ())
        // {
            Timer->stop();
             emit  Finish();
        // }
     }

     render();

}

To copy to clipboard, switch view to plain text mode 

Any theories on this consumption.
regards

[d_stranz]

Because in the first version of Update() that you posted, the single-shot timer does not fire until after the control returns to the event loop, so render() is never called in the Update() method. Also in that code, "Timer" refers to a different instance of QTimer; the call to QTimer::singleShot() creates a temporary QTimer instance that is destroyed once it times out and executes the render() slot.

In the second version of Update(), render() is always called.

Nothing curious about it. The two versions of your code are doing exactly what you've told them to do.