Destroyed while thread is still running

neda

Hi
When I close my application, it still exists in the task manager.
I try to kill all threads to solve this problem.

int main(int argc, char *argv[])
{
    QCoreApplication::setAttribute(Qt::AA_EnableHighDpiScaling);
    QApplication app(argc, argv);
    QQuickView engine;

    QApplication::setOrganizationName("myapp");
    QApplication::setOrganizationDomain("myapp");
        
    PCAPNetwork myPort;    
   
    /* Thread */
    QThread::currentThread()->setObjectName("MainThread");
    QThread * thread = new QThread();
    thread->setObjectName("PortThread");
    myPort.moveToThread(thread);
    thread->start();

    QObject::connect(thread, SIGNAL(started()), &myPort, SLOT(openPort()));
    QObject::connect(thread, SIGNAL(finished()), thread, SLOT(quit()));
    QObject::connect(thread, SIGNAL(finished()), thread, SLOT(terminate()));
    QObject::connect(thread, SIGNAL(finished()), thread, SLOT(deleteLater()));
    QObject::connect(thread, &QThread::finished, qApp, &QObject::deleteLater);
    QObject::connect(thread, &QThread::finished, &app, &QObject::deleteLater);

    QObject::connect(&app, &QApplication::aboutToQuit, thread, &QThread::quit);
    QObject::connect(&app, &QApplication::aboutToQuit, thread, &QThread::terminate);
           

    QObject::connect(qApp, SIGNAL(aboutToQuit()), thread, SLOT(quit()));
    QObject::connect(qApp, SIGNAL(aboutToQuit()), thread, SLOT(terminate()));
    QObject::connect(qApp, SIGNAL(aboutToQuit()), thread, SLOT(deleteLater()));

    /* End Thread */
    /* End PCAPNetwork */

    engine.setSource(QUrl(QStringLiteral("qrc:/main.qml")));
    
    
    int result = QApplication::exec();

    thread->quit();
    thread->terminate();
    thread->wait();
    return result;
}

I have written a lot of codes to try, but I still have this error.

QThread: Destroyed while thread is still running

Christian Ehrlicher

@neda said in Destroyed while thread is still running:

PCAPNetwork

You should look where this class blocks the thread event loop so QThread::quit() can't do anything.

neda

@Christian-Ehrlicher

Thanks
How can I find where this class blocks the thread?
This class is very simple and has just three functions (openPort, packet_handler, sendData).

Christian Ehrlicher

@neda said in Destroyed while thread is still running:

How can I find where this class blocks the thread?

Look at the source maybe? We don't have them...
When a thread can not quit you're blocking it's execution. Don't do this.

neda

@Christian-Ehrlicher
Thank you
That's right
After open the port, I have a loop.

/* start the capture */
    pcap_loop(adhandle, 0, packet_handler, NULL);

Christian Ehrlicher

The documentation to pcap_loop tells you how to stop this function.

neda

@Christian-Ehrlicher
Thank you

void PCAPNetwork::closePort()
{
  qDebug()<<"close port .... ";
   pcap_breakloop(adhandle);
   pcap_close(adhandle);
}

The "closePort" function is never called.

QObject::connect(qApp, SIGNAL(aboutToQuit()), &myPort, SLOT(closePort()));
QObject::connect(qApp, SIGNAL(aboutToQuit()), thread, SLOT(deleteLater()));

Christian Ehrlicher

QCoreApplication::aboutToQuit() is called just before QCoreApplication gets destroyed. So how should this work?

neda

@Christian-Ehrlicher
Thanks
That's right

main.qml
onClosing: {
        myPort.closePort();
    }

But I have the same error.
I'm trying to check codes of function "closePort"