os_rwl_wheld
#define os_rwl_wheld(lock) rw_write_held(lock)
#define os_rwl_wheld(lock) (lockstatus(lock, curthread) == LK_EXCLUSIVE)
#define os_rwl_wheld(lock) ((lock)->holder == haiku_get_current_thread_id())
#define os_rwl_wheld(lock) rw_write_held(lock)
#define os_rwl_wheld(lock) (lockstatus(lock, curthread) == LK_EXCLUSIVE)
#define os_rwl_wheld(lock) ((lock)->holder == haiku_get_current_thread_id())