mutex_lock
#define mutex_lock(a) (void)0
#define mutex_lock(m) __libc_mutex_lock((m))
#define mutex_lock(m) __nothing
#define mutex_lock(lock) mtx_enter(lock)
#define mutex_lock(lock) mutex_enter(lock)
mutex_lock(pthread_mutex_t *m, const struct timespec *ts)
#define mutex_lock(a, b) pthread_mutex_lock(a)