RW_WRITE_WANTED
const char *ww = (w & RW_WRITE_WANTED) ? " write_wanted" : "";
lock_wait = RW_HAS_WAITERS | RW_WRITE_WANTED;
RW_HAS_WAITERS | RW_WRITE_WANTED;
new |= RW_WRITE_WANTED;
ASSERT(lp->rw_wwwh & RW_WRITE_WANTED);
new |= RW_WRITE_WANTED;
#define RW_WRITE_CLAIMED (RW_WRITE_LOCKED | RW_WRITE_WANTED)