How to debug a Not Responding program element
My Delphi program has a somewhat complex level selection menu which loads various items including graphics, level information and a treeview for selecting packs and levels.
Up until recently, the menu has started to hang and occasionally become unresponsive, occasionally requiring closing the program altogether using Task Manager.
My question is, how would I go about locating the source of the problem? Something as generic as a program hang which only happens occasionally doesn’t really point towards anything specific, but the chances are that it is something specific which is causing the issue.
I’m happy to share the entire .pas file for the level select menu (about 1700 lines of code) if anyone thinks it necessary, but I wondered if there might be a specific way to find out where loading bottlenecks might be happening, or how to isolate whatever is causing the program to hang. I use RAD Studio 10.4 (the program doesn’t compile at all on 11 or higher).
Suggestions welcome, thank you.
I was looking for an excuse to use VTune again 😉
(thanks to Anders map2pdb!)
and here's a flame graph of what's going on while the form is shown:
(this is without any sounds being played in the background since I don't have BASS dll lying around - and I'm glad I don't)
So the Sleep in ApplicationIdle wastes about one third of the total time. And while FormCreate does spend quite some time in InitializeTreeView, half of it is now because the OnExpanded handler is called during it (that's what @Lars Fosdal was hinting at). But in the end most of the time is spent reading and parsing the level info that is spread over hundreds of text files.
