[Qt-interest] UI Interaction Freezing when using QGraphicsView - How to Debug?

[Josiah Bryan]

william.crocker at analog.com wrote:
>> Thanks - but I tried that. Since the whole system UI freezes (I mean 
>> everything), the debugger (gdb in a konsole) doesn't even respond to 
>> Ctrl+C at the time to break in. By the time it response to Ctrl+C, the 
>> freeze is over, and it just stops at some point deep in libGLcore.so.
>>
> 
> Run in a debugger on machine A, but display on machine B.
> When the UI freezes on machine B you will still
> be able to interact with the debugger running on machine A
> and see where all of the threads are.

E.g. you mean from machineB, do ssh -Y machineA and run gdb pbuffers2? 
Or is there a more exotic way to run gdb but display on another machine?

> Profile the code and see if you get any hints from that.

Hadn't thought about using valgrind. I'll try, doubt it will help, but 
I'll try.

> If it really freezes and CPU usage goes to zero,
> could this be a hardware/device-driver problem.

Nope, right before/after freeze, cpu usage on both cores (according to 
gkrellm) is around 80-90%.

Any idea why pbuffers2 freezes but pbuffers example does not?

-josiah