Confusion about QThread & deleteLater

[KtrNozomi]

I have a problem with how Qt handles objects destruction related to QThread.

m_worker->moveToThread(m_thread);
connect(m_thread, &QThread::finished, m_worker, &QObject::deleteLater);

• m_thread belongs to the UI main thread, after moveToThread the m_worker thread affinity belongs to the sub thread. So the AUTO connection should be Qt::QueuedConnection which leads deleteLater to execute in the sub thread.
• However, the thread has been finished and the thread event loop is stopped, deleteLater may never be executed. (I know deleteLater is asynchronous, maybe deleteLater is executed but the real "delete" may never be handled in the sub thread event loop?)

It seems a paradox, what's the real problem here? I have read QObject::deleteLater here but still feel confused. Thanks a lot for answering!

[jsulm]

@KtrNozomi "If deleteLater() is called on an object that lives in a thread with no running event loop, the object will be destroyed when the thread finishes."
https://doc.qt.io/qt-6/qobject.html#deleteLater

[Hanson]

@KtrNozomi "When this signal is emitted, the event loop has already stopped running. No more events will be processed in the thread, except for deferred deletion events. This signal can be connected to QObject::deleteLater(), to free objects in that thread."
https://doc.qt.io/qt-6/qthread.html#finished

[KtrNozomi]

@Hanson @jsulm Thanks a lot!