Force garbage collection in Qt
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I guess you mean stuff that has been deleted by Qt with the deleteLater() function?
The closest you might get to forcing a garbage collection like thing is to use the sendPostedEvents(Q_NULLPTR,QEvent::DeferredDelete) of your application at an appropriate time.
It might be better to delete the objects yourself and set their pointers to NULL after deleting them so you can check for that later. -
Hi
as notes
http://doc.qt.io/qt-5/qobject.html#deleteLaterAlso if you think your issue is that you are using a widget after it has been deleted then you can use this signal
void QObject::destroyed(QObject *obj = Q_NULLPTR)
It will then tell you when dying and u can clear pointer or what the real issue is. -
I tried sendPostedEvents(Q_NULLPTR,QEvent::DeferredDelete) but it does not seem to make my problems appear more often. I still have to wait at least 30 seconds between the moment I close my panel and the moment the destructors are called.
I know how to correct it but I would just like it to fail fast.
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Hi
if you have many loops/strangulate the event loop, it might take a while before its actually deleted. -
I have some bugs appearing in my application because I keep pointers to objects that are deleted by the garbage collection of Qt. I know this is bad but I would like to know if there is a way to make garbage collection appear more often so I can more easily find out about these problems.
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Given we are talking about QObjects, you can use QPointer intead of a raw pointer. It becomes null when the object gets destroyed
"La mort n'est rien, mais vivre vaincu et sans gloire, c'est mourir tous les jours"
~Napoleon BonaparteOn a crusade to banish setIndexWidget() from the holy land of Qt
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Given we are talking about QObjects, you can use QPointer intead of a raw pointer. It becomes null when the object gets destroyed
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@gchauvie you can replace the Q_NULLPTR argument with a pointer to specific widgets. As I said it all about the appropriate time when you use that function.
Directly deleting the objects with delete is the fasted way but you must write your program to manage the pointers you will delete by initialising them to NULL resetting them to NULL after delete and checking for null before you reallocate etc.... you must be very careful which objects you delete when you do it this way.
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@gchauvie
If you make your UI with QML, than you can use the global objectgc()to manualy trigger the garbage collector.But thats a QML feature only, I think.
