do_raw_read_trylock
extern int do_raw_read_trylock(rwlock_t *lock);
if (do_raw_read_trylock(lock)) {
LOCK_CONTENDED(lock, do_raw_read_trylock, do_raw_read_lock);
LOCK_CONTENDED(lock, do_raw_read_trylock, do_raw_read_lock);
LOCK_CONTENDED(lock, do_raw_read_trylock, do_raw_read_lock);
LOCK_CONTENDED(lock, do_raw_read_trylock, do_raw_read_lock);