order_id
const struct order_id* o1 = e1;
const struct order_id* o2 = e2;
const struct order_id* o1 = e1;
const struct order_id* o2 = e2;
const struct order_id* o1 = e1;
const struct order_id* o2 = e2;
insert_lock(rbtree_type* all, struct order_id* id)
struct order_id prev_id, now_id;
struct order_id id;