Just by loading one page and coming back, we can't make out the memory leak. Try multiple times like this. If you see a increase & no decrease then we can conclude memory leak. If you can send me the complete example, we can try as well.
About "Object's pointers & Memory"
I also take an advise from a Pro in C++ & memory management.
His solution is implement a Factory Pattern to Create/Delete Object's pointers
(also free memory when an instance had no pointer to it.)
(I think I'll give it a try)
There's one thing bothering me though ... You said you can't afford to drop a frame, but you use datagrams, which are inherently unsafe (in that manner) ... otherwise I'd assume it's what @SGaist said - probably your processing is lagging behind and there's work queuing up ...
It's a mistake when I copy the code from other place.
Here are the exact code below that I just write for this network test.
The bigger the count of request sent in a loop, the more consumed virtual memory of this program.
And after finished all of these http requests, the Virtual Memory of this program did not reduce.
However, when I add a qWait(1) between every request, the memory will not goes up when the number of sent requests grows. But the memory still doesn't go down when I delete everything I used to access network.
It seems when concurrently create and send a large amount of http requests through QNetworkAccessManager, the memory leakage will happen.
QThread constructor moveToThread( this); is error. QThread class is just control object and is not actually a separate thread. You should move class base on QObject (with would be wrapper for QTcpSocket communication) or QTcpSocket to separate thread.
2.. Don't know if this is Ui application but You are using blocking approach (may be ok for Your case)