def __cleanup_thread(self, event):
        """
        Auxiliary method for L{_notify_exit_thread}
        and L{_notify_exit_process}.
        """
        tid = event.get_tid()

        # Cleanup running breakpoints
        try:
            for bp in self.__runningBP[tid]:
                self.__cleanup_breakpoint(event, bp)
            del self.__runningBP[tid]
        except KeyError:
            pass

        # Cleanup hardware breakpoints
        try:
            for bp in self.__hardwareBP[tid]:
                self.__cleanup_breakpoint(event, bp)
            del self.__hardwareBP[tid]
        except KeyError:
            pass

        # Cleanup set of threads being traced
        if tid in self.__tracing:
            self.__tracing.remove(tid)