XBBF_READ_ONLY
if ((xbb->flags & XBBF_READ_ONLY) != 0) {
if ((xbb->flags & XBBF_READ_ONLY) == 0)
if ((xbb->flags & XBBF_READ_ONLY) == 0)
xbb->flags & XBBF_READ_ONLY
xbb->flags |= XBBF_READ_ONLY;