Signals & Slots problem

[cupersuper]

Hi,
I have some kind of loop using signals & slots. My application crashed when program do 3580 iterations on Qt4.8. I can't understand why crash. Please kindly help.

//main.cpp
int main(int argc, char *argv[])
{
...
    MainWindow w;
    Second s;
    QObject::connect(&w,SIGNAL(go()),&s,SLOT(go()));
    QObject::connect(&s,SIGNAL(back()),&w,SLOT(back()));
...
}
 
 
//mainwindow.h
class MainWindow : public QMainWindow
{
...
  private:
	int VALUE;
    int MAX_VALUE;
 
  private slots:
    void on_pushButton_clicked();
 
  public slots:
    void back();
 
  signals:
    void go();
};
 
 
//mainwindow.cpp
void MainWindow::on_pushButton_clicked()
{
    VALUE = 0;
    MAX_VALUE = 10000;
 
    emit go();
}
 
void MainWindow::back()
{
    qDebug() << VALUE;
 
    if(VALUE<MAX_VALUE)
    {
        VALUE++;
        emit go();
    }
}
 
 
//second.h
class Second : public QObject
{
...
signals:
    void back();
 
public slots:
    void go();
};
 
 
//second.cpp
void Second::go()
{
    emit back();
}

//main.cpp
int main(int argc, char *argv[])
{
...
    MainWindow w;
    Second s;
    QObject::connect(&w,SIGNAL(go()),&s,SLOT(go()));
    QObject::connect(&s,SIGNAL(back()),&w,SLOT(back()));
...
}


//mainwindow.h
class MainWindow : public QMainWindow
{
...
  private:
	int VALUE;
    int MAX_VALUE;

  private slots:
    void on_pushButton_clicked();

  public slots:
    void back();

  signals:
    void go();
};


//mainwindow.cpp
void MainWindow::on_pushButton_clicked()
{
    VALUE = 0;
    MAX_VALUE = 10000;

    emit go();
}

void MainWindow::back()
{
    qDebug() << VALUE;

    if(VALUE<MAX_VALUE)
    {
        VALUE++;
        emit go();
    }
}


//second.h
class Second : public QObject
{
...
signals:
    void back();

public slots:
    void go();
};


//second.cpp
void Second::go()
{
    emit back();
}

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test2.zip

Thanks;

[Lesiok]

When the sender and receiver of signal are in this same thread emitting signal is this same like calling procedure. So You have stack overflow. Read more about QObject::connect and use last parameter to create queued connection.