Re: [AD] Program continues running in background when CTRL-ALT-DEL used, but not when ALT-TAB used.

[Andrei Ellman <ae-a-alleg@xxxxxxxxxx>]

Peter Wang wrote:
> On 2006-12-28, Andrei Ellman <ae-a-alleg@xxxxxxxxxx> wrote:
> > Hi,
> >
> > I've noticed that whenever I switch out of an Allegro app using the 
> > CTRL-ALT-DEL combination and then press the task-manager button, my 
> > allegro app continues to run in the background (the app's cpu-usage is 
> > 99% and when I switch back in, the app looks like it's been running 
> > continuously).
>
> Does the program get the WM_ACTIVATE message in this case? (line ~259 in
> src/win/wwnd.c)

Forgot to mention that I've only tried this with fullscreen apps 
(windowed Allegro apps cannot be minimised).

I just tried placing a breakpoint on the line after 'case WM_ACTIVATE:' 
in wwnd.c and when using both ALT+TAB and CTRL+ALT+DEL, the breakpoint 
is hit. I even tried moving the breakpoint to _win_switch_out(); one 
line later and again, in both cases, the breakpoint was hit.

One thing I do notice is that when not using breakpoints, If I switch 
out using ALT+TAB, the resolution and colourdepth are immediately 
restored, whereas if I switch out with CTRL+ALT+DEL, my resolution and 
colourdepth remain the same as that of the app while the "Windows 
Security" dialog is displayed, until I press the "Task Manager" button 
and then they return to that of the desktop.

Unfortunately, this meant that when debugging and switching out the 
CTRL+ALT+DEL way, the breakpoint was hit before the resolution,etc. 
could be restored, and instead of seeing MSVC, I saw a white background, 
so further debugging was made difficult. Fortunately, I've set up MSVC 
to make a noise whenever a breakpoint is hit, so I at least know that 
_win_switch_out() was called while (or before?) the "Windows Security" 
dialog is displayed.

I also tried running a mingw build of the app, and the same thing 
happened (but I did not debug the mingw version).


AE.