Could slot function and mouseMoveEvent be possibly excuted concurrently in a muti-cores machine?

[Limer]

class MyScene : public QGraphicsScene
{
    ...

    MyScene()
    {
        ...

        m_mouseEventEnabled = false;
        thread.start();
        connect(&thread, SIGNAL(finished()), this, SLOT(mouseEventEnabledSlot()));

        ...
    }
    
    ...

public slots:

    void mouseEventEnabledSlot()
    {
        m_mouseEventEnabled = true;
    }

protected:

    void mouseMoveEvent(QGraphicsSceneMouseEvent* event)
    {
        if (m_mouseEventEnabled)
        {
            do_mouse_move_thing();
        }
    }
    
private:

    bool m_mouseEventEnabled;
    MyThread thread;

    ...
}

Just as the code show, when the thread finishes, m_mouseEventEnabled will be set to true, for variable m_mouseEventEnabled, this is a writing behavior,

but the m_mouseEventEnabled in function mouseMoveEvent may always do a reading behavior,

The program will be run in a muti-cores machine, and what I want to know is that whether the two behaviors can possibly excute concurrently?

( I know little about the underlying implementation mechanism in Qt, but after I google the relevant articles, I think it will never happen, just my plain view).

[VRonin]

change bool m_mouseEventEnabled; to std::atomic_bool m_mouseEventEnabled;. The rest should work

[Limer]

@VRonin What you mean is the two behaviors can be excuted concurrently ?

[jsulm]

@Limer said in Could slot function and mouseMoveEvent be possibly excuted concurrently in a muti-cores machine?:

What you mean is the two behaviors can be excuted concurrently ?

yes

[JKSH]

Normally, a widget's slot functions and event functions are run in the GUI thread.

It is possible to run function concurrently from mouseMoveEvent() by running the function in a different thread. However, it is best to implement that function in a different class (unless you really really know what you are doing)