Re: gdb and too many threads causes SIGTRAP

[Daniel Jacobowitz <drow@false.org>]

On Wed, May 25, 2005 at 03:51:06PM -0700, Kaarthik Sivakumar wrote:
> Hi
> 
> We are developing a multi-threaded application on RH9 which creates and 
> deletes a large number of threads in a short time. After this program runs 
> for sometime, gdb fails with a SIGTRAP in a thread that is at 
> __ntpl_death_event() (when the thread wants to quit). Following some of the 
> mails at gdb-patches, I noticed a thread (subject: [RFC]: fix for recycled 
> thread ids) that seems to address this issue.
> 
> According to that mail thread, and this specific mail 
> http://sources.redhat.com/ml/gdb-patches/2004-03/msg00672.html, a fix was 
> issued to check for TD_DEATH when possible and to attach to threads sooner 
> when thread ids are being reused. This fix seems to be available in gdb 
> 6.2.1, so we used that to debug the application. But this still does not seem 
> to have fixed the problem. I can confirm that the code to test for TD_DEATH 
> is activated and that glibc version is 2.3.2, so this fix should apply and 
> work. But it doesnt.
> 
> Is there anything else I should be checking? If you need more information, 
> please let me know. The OS is RH 9, with just the gdb 6.2.1 tar.bz2 compiled 
> and being used. Thanks.

If you are compiling a new version of GDB anyway, please try a more
current release - if possible, a current CVS snapshot.  After that, if
you still have trouble, it may be a kernel problem.  Current versions
of GDB should not have this problem.

-- 
Daniel Jacobowitz
CodeSourcery, LLC