Issues about the function of remove() and clear() from QMap

Yandong Luo

Hi, I try to use buttons to delete all of the items in QMap. So I use the function of clear() from QMap. But when I click the button, the program exits abnormally. What happened to this?

void MainWindow::Btn_Read_Click(){
    if(Component_List[Button_Index-1].Button_Read->text() == tr("Stop")){
     port->PauseRead();
      }
}

.h file

QMap<int, QByteArray> m_writeData;

void Serial_Service::PauseRead()
{
    qDebug()<<"pause";
    /* qDeleteAll(m_writeData.begin(),m_writeData.end());*/

    m_writeData.clear();
    m_timer->stop();
}

Christian Ehrlicher

As always - use a debugger and see where it crashes.

nagesh

@Yandong-Luo debug output shows some print "data : ..... length : 9" it means crashing is not happening due to map.clear()/PauseRead().
Use debugger to locate the crash

Yandong Luo

@nagesh @Christian-Ehrlicher Thanks for your help! I use debugger to locate the crash and I found the program will run to this function and then crash. I still don't know what happens. if I don't use clear(), the program will not crash.

nagesh

Does m_Writedata map object being used in any thread during clear operation?

Yandong Luo

@nagesh Really Thanks for your help. I solved it!