A GDB breakpoint can totally freeze an X11 display when debugging
a GUI application, if the app makes a "server grab."
For example, if the application has a pull-down menu and I put
a breakpoint in the menu's callback, then the following happens:
- the menu is opened and an X11 server grab happens (in order to
catch all mouse events even if they are outside the menu's window);
- the callback is called and GDB stops on it due to the breakpoint;
- GDB expects commands from the user, but the user cannot type
anything anywhere in the display because of the server grab;
of course, the menu cannot be closed because the app is stopped.
One way to get out of this is to login through the network and
kill GDB. Usually, I access the machine through a VNC remote
display. In addition, I telnet into the machine and run GDB in it,
sending the display to the VNC/X11 server. When the breakpoint is
reached, I can still control GDB through the telnet session.
Is there a better way? I would imagine that GDB could automatically
try to end an X11 server grab every time it displays its prompt.
--
Pierre Sarrazin <[EMAIL PROTECTED]>
_______________________________________________
Bug-gdb mailing list
[EMAIL PROTECTED]
http://mail.gnu.org/mailman/listinfo/bug-gdb
