stk-code_catmod/src/network/network_timer_synchronizer.hpp

111 lines
4.1 KiB
C++

//
// SuperTuxKart - a fun racing game with go-kart
// Copyright (C) 2018 SuperTuxKart-Team
//
// This program is free software; you can redistribute it and/or
// modify it under the terms of the GNU General Public License
// as published by the Free Software Foundation; either version 3
// of the License, or (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
#ifndef HEADER_NETWORK_TIMER_SYNCHRONIZER_HPP
#define HEADER_NETWORK_TIMER_SYNCHRONIZER_HPP
#include "config/user_config.hpp"
#include "network/stk_host.hpp"
#include "utils/log.hpp"
#include "utils/time.hpp"
#include "utils/types.hpp"
#include <atomic>
#include <cstdlib>
#include <deque>
#include <numeric>
#include <tuple>
class NetworkTimerSynchronizer
{
private:
std::deque<std::tuple<uint32_t, uint64_t, uint64_t> > m_times;
std::atomic_bool m_synchronised, m_force_set_timer;
public:
NetworkTimerSynchronizer()
{
m_synchronised.store(false);
m_force_set_timer.store(false);
}
// ------------------------------------------------------------------------
bool isSynchronised() const { return m_synchronised.load(); }
// ------------------------------------------------------------------------
void enableForceSetTimer()
{
if (m_synchronised.load() == true)
return;
m_force_set_timer.store(true);
}
// ------------------------------------------------------------------------
void addAndSetTime(uint32_t ping, uint64_t server_time)
{
if (m_synchronised.load() == true)
return;
if (m_force_set_timer.load() == true)
{
m_force_set_timer.store(false);
m_synchronised.store(true);
STKHost::get()->setNetworkTimer(server_time + (uint64_t)(ping / 2));
return;
}
const uint64_t cur_time = StkTime::getRealTimeMs();
// Discard too close time compared to last ping
// (due to resend when packet loss)
const uint64_t frequency = (uint64_t)((1.0f /
(float)(stk_config->m_network_state_frequeny)) * 1000.0f) / 2;
if (!m_times.empty() &&
cur_time - std::get<2>(m_times.back()) < frequency)
return;
// Take max 20 averaged samples from m_times, the next addAndGetTime
// is used to determine that server_time if it's correct, if not
// clear half in m_times until it's correct
if (m_times.size() >= 20)
{
uint64_t sum = std::accumulate(m_times.begin(), m_times.end(),
(uint64_t)0, [cur_time](const uint64_t previous,
const std::tuple<uint32_t, uint64_t, uint64_t>& b)->uint64_t
{
return previous + (uint64_t)(std::get<0>(b) / 2) +
std::get<1>(b) + cur_time - std::get<2>(b);
});
const int64_t averaged_time = sum / 20;
const int64_t server_time_now = server_time + (uint64_t)(ping / 2);
int difference = (int)std::abs(averaged_time - server_time_now);
if (std::abs(averaged_time - server_time_now) <
UserConfigParams::m_timer_sync_difference_tolerance)
{
STKHost::get()->setNetworkTimer(averaged_time);
m_force_set_timer.store(false);
m_synchronised.store(true);
Log::info("NetworkTimerSynchronizer", "Network "
"timer synchronized, difference: %dms", difference);
return;
}
m_times.erase(m_times.begin(), m_times.begin() + 10);
}
m_times.emplace_back(ping, server_time, cur_time);
}
};
#endif // HEADER_NETWORK_TIMER_SYNCHRONIZER_HPP