MUTEX_TYPE_SPIN
#define MUTEX_TYPE_SPIN(lp) ((lp)->m_spin.m_dummylock == LOCK_HELD_VALUE)
#define MUTEX_TYPE_SPIN(lp) ((lp)->m_type == MUTEX_SPIN)
#define MUTEX_TYPE_SPIN(lp) ((lp)->m_spin.m_dummylock == LOCK_HELD_VALUE)