k5_os_mutex_assert_unlocked
# define k5_os_mutex_assert_unlocked k5_os_nothread_mutex_assert_unlocked
# define k5_os_mutex_assert_unlocked(M) \
# define k5_os_mutex_assert_unlocked(M) k5_pthread_assert_unlocked(&(M)->p)
# define k5_os_mutex_assert_unlocked(M) ((void)0)