QThread: slot quit() 永远不会被调用，因此线程 wait() 是永远的

Question

I have the exact same problem as described QThread won't stop / does not process a signal but with a twist. I cannot get it to work even with QCoreApplication::processEvents() to my while loop. I followed this blog post and ended up like as follows:

MediaController.cpp

void MediaController::buttonPlayClicked(bool checked)
{
    if (checked)
    {
        m_loopThread = new QThread;
        m_playPauseworker = new PlayPauseWorker;
        m_playPauseworker->moveToThread(m_loopThread);
        connect(m_playPauseworker, &PlayPauseWorker::dataReady, this, &MediaController::onDataReady);
        connect(m_loopThread, &QThread::started, m_playPauseworker, &PlayPauseWorker::process);

        connect(m_playPauseworker, &PlayPauseWorker::finished, m_loopThread, &QThread::quit); // <-- never works
       
        connect(m_playPauseworker, &PlayPauseWorker::finished, m_playPauseworker, &PlayPauseWorker::deleteLater);
        connect(m_loopThread, &QThread::finished, m_loopThread, &QThread::deleteLater);
        m_loopThread->start();
    }
    else
    {
        m_loopThread->requestInterruption();
    }
}

The above slot is called every time play/pause checkable button is clicked. Thread and worker are created on the main thread.

PlayPauseWorker.cpp

void PlayPauseWorker::process()
{
    while (!QThread::currentThread()->isInterruptionRequested())
    {
            // heavy computations

            emit dataReady(std::tuple<QImage, QImage, QImage>>); // <-- works!
            
            QCoreApplication::processEvents(); // <-- doesn't help with quit()
    }           

    emit finished(); // <-- emits the signal but quit() not called
}

On further processing, when i access wait() to see if my thread has exited, it never returns.

In addition to quit() slot never called, i noticed my GUI becomes very choppy when the thread is running. I sometimes can/cannot click on other buttons or play with UI. I went through a lot of SO posts but couldn't figure out a way to cleanly exit the thread whenever i need to. Not sure where am i going wrong.

Answer 1

After trying out a lot of suggestions i still couldn't figure out why emit finished() doesn't quit the thread. So, as a last resort, i used this->thread->quit() to achieve the same.

But thanks to all the commenters here, i narrowed down on laggy/choppy gui issue. My emit data(std::tuple<QImage, QImage, QImage>>) was setting pixmap on QGraphicsScene on a loop without removing the already set pixmap on the scene leading to huge memory leak and ultimately crash.