[Asterisk-Dev] How to debug a dead lock in asterisk ?

[TC]

Hi
In testing some of the newer code in agents and queues,
Mark has logged in and done some debugging with gdb to identify
the cause of a system dead lock.

I should have reviewd with him the techniques to identify the dead locks but
did not :(.
Can anyone here lay out the procedure to identify a system dead lock
when using gdb to attach to the root asterisk process.