URWLOCK_READ_WAITERS
URWLOCK_WRITE_WAITERS | URWLOCK_READ_WAITERS);
URWLOCK_READ_WAITERS)) != 0 &&
!(state & URWLOCK_READ_WAITERS)) {
&oldstate, state | URWLOCK_READ_WAITERS);
&oldstate, state & ~URWLOCK_READ_WAITERS);
} else if (state & URWLOCK_READ_WAITERS) {
if (state & URWLOCK_READ_WAITERS) {