AP_F_EXCLUSIVE_ACCESS
KKASSERT((ap->ap_flags & AP_F_EXCLUSIVE_ACCESS) == 0);
ap->ap_flags |= AP_F_EXCLUSIVE_ACCESS;
KKASSERT((ap->ap_flags & AP_F_EXCLUSIVE_ACCESS) != 0);
ap->ap_flags &= ~AP_F_EXCLUSIVE_ACCESS;
} else if ((ap->ap_flags & AP_F_EXCLUSIVE_ACCESS) || ap->ap_expired) {
if (xxx AP_F_EXCLUSIVE_ACCESS)