Re: Problem with GUI not (always) updating...

[Tristan Van Berkom <tvb gnome org>]

On Mon, 2007-04-02 at 13:58 +0200, Matthias Scheer wrote:
> Hi all,
> 
> I'm developing a computational tool with a nice GUI using GTK2+ and 
> Glade3. The OS is Ubuntu 6.10 with Gnome UI. Now I have encountered some 
> strange behaviour.
> 
> The application essentially asks for alot of parameters for the user to 
> enter, has a progress bar and a start, pause and exit button. When the 
> users hits start, I'm spawning a new thread (using pthreads) and let the 
> signal handler of start button return to the gtk_main() loop. This is 
> required because the computation takes quite some time and the user 
> should have the possibility to pause the program.
> 
> Now I've run into some 'indeterministic' effects. In about half of the 
> test runs, the GUI keeps accessible to the user, i.e. eyecandy on the 
> button on mouse-over, and the program works normally. In the other half, 
> the GUI freezes, but the computation finishes normally. Strangely, the 
> program reacts on clicks on the GUI, i.e. it pauses, exits etc, but the 
> GUI itself is frozen.
> 
> I'm running kernel 2.6.20.3 with the xenomai real-time patch.
> 

You say that when the program appears to be unresponsive, it still does
in fact respond to the "pause"/"quit" buttons ?

My guess is that your application is starving the whole computer, a
mouse over is usually smart enough to not show any effects if the event
arrives late, but a button click is a more serious event and will
eventually get treated, even if its a second late.

Probably by sleeping a little bit in your worker thread or finding
a way to be more cooperative everything will work more as expected.

Cheers,
          -Tristan