BUF_ATTR_DEQUEUED
buf->attr |= BUF_ATTR_DEQUEUED;
buf->attr |= BUF_ATTR_DEQUEUED;
buf->attr |= BUF_ATTR_DEQUEUED;
if (buf->attr & BUF_ATTR_DEQUEUED) {
buf->attr &= ~BUF_ATTR_DEQUEUED;
if (buf->attr & BUF_ATTR_DEQUEUED) {
buf->attr &= ~BUF_ATTR_DEQUEUED;