cache warm一例

td::unordered_map<int32_t, order> my_orders;
...
packet_t* p;
while(!exit) {
    p = get_packet();
    // If packet arrived
    if (p) {
        // Check if the identifier is known to us
        auto it = my_orders.find(p->id);
        if (it != my_orders.end()) {
            send_answer(p->origin, it->second);
        }
    }
}

std::unordered_map<int32_t, order> my_orders;
...
packet_t* p;
int64_t total_random_found = 0;
while(!exit) {
    // 增加个检查header 然后再判断packet，不满足就去warm
    // 如果header没满足，packet必不满足
    if (packet_header_arrived()) {
        p = get_packet();
        // If packet arrived
        if (p) {
            // Check if the identifier is known to us
            auto it = my_orders.find(p->id);
            if (it != my_orders.end()) {
                send_answer(p->origin, it->second);
            }
        }
    } else {
        // 不干活就Cache warming 
        auto random_id = get_random_id();
        auto it = my_orders.find(random_id);
        // 随便干点啥避免被编译器优化掉
        total_random_found += (it != my_orders.end());
    }
}
std::cout << "Total random found " << total_random_found << "\n";