Re: emacs-X11 freezes with mouse cut and paste

[Ken Brown <kbrown at cornell dot edu>]

On 4/4/2019 12:25 PM, Rockefeller, Harry wrote:
>> Alternatively, instead of running emacs under gdb, you could just run emacs as you normally do and then attach gdb when emacs freezes.  >("gdb -p <PID>")  At that point, a backtrace of all threads would be useful.

> It happened again.  Attached to PID as shown above.  (gdb) list gave same result as above.
> (gdb) bt
> #0  0x00000000773bafb1 in ntdll!DbgBreakPoint () from /cygdrive/c/Windows/SYSTEM32/ntdll.dll
> #1  0x0000000077462e08 in ntdll!DbgUiRemoteBreakin () from /cygdrive/c/Windows/SYSTEM32/ntdll.dll
> #2  0x00000000772659cd in KERNEL32!BaseThreadInitThunk () from /cygdrive/c/Windows/system32/kernel32.dll
> #3  0x000000007739a561 in ntdll!RtlUserThreadStart () from /cygdrive/c/Windows/SYSTEM32/ntdll.dll
> #4  0x0000000000000000 in ?? ()
> Backtrace stopped: previous frame inner to this frame (corrupt stack?)
> 
> Does this tell me the problem is not Cygwin?  Perhaps BLODA or bad hardware, maybe bad mouse?

Not yet.  When you attach gdb to a process, it creates a new thread to be used 
by gdb.  What you're seeing above is the backtrace in that thread.  You need to 
switch to the main thread before you can get a useful backtrace:

(gdb) thread 1
(gdb) bt

Or you can just get a backtrace of all threads:

(gdb) thread apply all bt

The "info threads" command might clarify what's going on.

Ken

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