Re: Debug of Test 15 (cgf input needed)

[Christopher Faylor <cgf at redhat dot com>]

On Sat, Apr 07, 2001 at 09:55:43PM -0400, Pierre A. Humblet wrote:
>At 08:14 PM 4/7/2001 -0400, Christopher Faylor wrote:
>
>>Some (most) select operations in cygwin actually need to resort to
>>polling so they do consume CPU.  The easiest way to find out what is
>>happening is to attach a gdb to the running process.
>
>Chris, can you elaborate? I have never done that until now.
>While the Xserver process is running, I launch gdb -nw, load the executable
>(file) and attach to the winpid. gdb tells me "attaching ... " and gets
>stuck. From another window I send a signal to the Xserver and gdb
>then gives me the prompt. Now what? The only info I have been able to
>get is the registers and the dlls ...

You need to investigate the stack frame, of course, with the "bt"
command.  You need to see what threads are active with the 'info
threads' command.  Then switch to the threads and do stack traces
there to see what's going on.

If you are debugging cygwin, you'll need to have an unstripped version
of the DLL built with gcc -g.

Hopefully this makes some sense.  I don't think I want to give a course
in basic debugging.  If this doesn't make sense then I assume that there
must be some information on the web somewhere on how to use gdb in
addition to the gdb info files.

cgf