problem with screen flicker & X server locking up with breakpoints in gdb

[Roger Moore]

> The screen in my app draws correctly, and stays drawn as expected;
> however, when I attempt to move graphics on the screen, I starts to
> flicker in an annoying way.
>
> The default drawing mode in the application I am writing software for is
> COPY, which is where the flicker occurs.  If I change the default
drawing
> mode to OR, then the flicker stops, but of course with the OR mode it
> draws an image and leaves it there, so when I move the cursor it leaves
a
> permanent trace of the object as it is being moved--hus it cannot be
> released to production.
>
> Does anyone have any suggestions as to why I am experiencing this
problem?
> We have some people who use the application all complain that the
flicker
> causes fatigue, and so are trying to remove this problem.
>
> Here is a stack trace,
>
> No symbol table info available.
> (gdb) info local
> No symbol table info available.
> (gdb) backtrace
> #0  0x00b5d402 in __kernel_vsyscall ()
> #1  0x00733243 in poll () from /lib/libc.so.6
> #2  0x0328b9ca in XtAddTimeOut () from /usr/lib/libXt.so.6
> #3  0x0328bf05 in _XtWaitForSomething () from /usr/lib/libXt.so.6
> #4  0x0328cfcf in XtAppNextEvent () from /usr/lib/libXt.so.6
> #5  0x001846f8 in xvtxi_wait_for_next_event () at
> /mnt/hgfs/vista/xvtdsp55/linux_x86/src/ptk/xm/xQueue.c:175
> #6  0x001abdd5 in xvtk_app_create (argc=1, argv=0xbfccf2b4, flags=0,
> task_eh=0x8ca3f76 <hookWinEventHandler(unsigned int, s_event*)>,
> config_p=0xbfccea88) at
> /mnt/hgfs/vista/xvtdsp55/linux_x86/src/ptk/xm/xmInit.c:211
> #7  0x08daa396 in xvt_app_create (argc=1, argv=0xbfccf2b4, flags=0,
> eh=0x8ca3f76 <hookWinEventHandler(unsigned int, s_event*)>,
> config=0xbfccea88) at
> /mnt/hgfs/vista/xvtdsp55/linux_x86/src/ptk/tapp.c:103
> #8  0x08ca5b75 in CApplication::Go (this=0x9078ae0, argc=1,
> argv=0xbfccf2b4, theMenuBarId=1000, theAboutBoxId=2002,
> theBaseName=0x8dcd1ea "vistawin", theApplicationName=0xbfccf000 "Seismic
> Processing 2D/3D", theTaskTitle=0xbfccef06 "Seismic Processing 2D/3D
> Project:") at capplctn.cpp:156
> #9  0x0805895c in main (argc=1, argv=0xbfccf2b4) at vistawin.cpp:572
>
> Please note that sometimes when when I try to set breakpoints in gdb or
> kdevelop in the application, it causes the whole X server to lock up.
>
> Do you have any suggestions?