ITLK_LOCKED
while (it->it_lock & ITLK_LOCKED) {
it->it_lock |= ITLK_LOCKED;
VERIFY(it->it_lock & ITLK_LOCKED);
it->it_lock &= ~ITLK_LOCKED;
ASSERT(it->it_lock & ITLK_LOCKED);
it->it_lock = ITLK_LOCKED;
while (it->it_lock & ITLK_LOCKED) {
it->it_lock |= ITLK_LOCKED;
ASSERT(it->it_lock & ITLK_LOCKED);
it->it_lock &= ~ITLK_LOCKED;