rt_sig_thread is a kernel module that creats a rt-thread and a kthread thathas a uniq process name and id. As name for the thread the rt-thread id is used. This kthread is only a "singal-dispatcher" for the rt-thread to passon unix signals sent via  kill -# PIDOF_KTHREAD  on to the rt-thread.Any singal other that SIG_KILL will wake up the rt-thrad - SIG_KILL will be sent on to the rt-thread as RTL_SIGNAL_CANCEL. The signal can be sent by calling pthread_delete_np() on the rt-thread or by setting the rt_threadssignal pending mask with bit-operations. both variants are safe as bit-operations are atomic.Note that the kthreads exit must be synchronized in cleanup module - the methodis not very elegant but should be safe. When the kthread exits its main loop it sets a global variable that is used by cleanup_module to wait on the kthreadexit.hofrat