TF_TIMER
CLR((*tp)->t_flags, TF_TIMER << timer);
if (*tp == NULL || !ISSET((*tp)->t_flags, TF_TIMER << timer) ||
SET((tp)->t_flags, TF_TIMER << (timer)); \
CLR((tp)->t_flags, TF_TIMER << (timer)); \
ISSET((tp)->t_flags, TF_TIMER << (timer))