    OVS_REQUIRES(ctb->lock)
{
    ovs_list_remove(&conn->exp_node);
    hmap_remove(&ctb->connections, &conn->node);
    atomic_count_dec(&ct->n_conn);
    if (conn->nat_info) {
        nat_clean(ct, conn, ctb);
    } else {
        delete_conn(conn);
    }
}
    OVS_REQUIRES(ctb->lock)
{
    ovs_list_remove(&conn->exp_node);
    hmap_remove(&ctb->connections, &conn->node);
    atomic_count_dec(&ct->n_conn);
    if (conn->nat_info) {
        nat_clean(ct, conn, ctb);
    } else {
        delete_conn(conn);
    }
}