diff --git a/source.list b/source.list
index 2dc1659aec..a530151757 100644
--- a/source.list
+++ b/source.list
@@ -460,6 +460,7 @@ core/alloc_type.hpp
core/backup_type.hpp
core/bitmath_func.cpp
core/bitmath_func.hpp
+core/checksum_func.hpp
core/container_func.hpp
core/dyn_arena_alloc.hpp
core/endian_func.hpp
diff --git a/src/aircraft_cmd.cpp b/src/aircraft_cmd.cpp
index 00d4ddad04..2ca4b84e16 100644
--- a/src/aircraft_cmd.cpp
+++ b/src/aircraft_cmd.cpp
@@ -40,6 +40,7 @@
#include "disaster_vehicle.h"
#include "newgrf_airporttiles.h"
#include "framerate_type.h"
+#include "core/checksum_func.hpp"
#include "table/strings.h"
@@ -2127,6 +2128,7 @@ static bool AircraftEventHandler(Aircraft *v, int loop)
bool Aircraft::Tick()
{
+ UpdateStateChecksum((((uint64) this->x_pos) << 32) | this->y_pos);
if (!this->IsNormalAircraft()) return true;
this->tick_counter++;
diff --git a/src/core/checksum_func.hpp b/src/core/checksum_func.hpp
new file mode 100644
index 0000000000..6845e14dae
--- /dev/null
+++ b/src/core/checksum_func.hpp
@@ -0,0 +1,33 @@
+/* $Id$ */
+
+/*
+ * This file is part of OpenTTD.
+ * OpenTTD 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, version 2.
+ * OpenTTD 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 OpenTTD. If not, see .
+ */
+
+/** @file checksum_func.hpp Checksum utility functions. */
+
+#ifndef CHECKSUM_FUNC_HPP
+#define CHECKSUM_FUNC_HPP
+
+#include "bitmath_func.hpp"
+
+struct SimpleChecksum64 {
+ uint64 state = 0;
+
+ void Update(uint64 input)
+ {
+ this->state = ROL(this->state, 1) ^ input ^ 0x123456789ABCDEF7ULL;
+ }
+};
+
+extern SimpleChecksum64 _state_checksum;
+
+inline void UpdateStateChecksum(uint64 input)
+{
+ _state_checksum.Update(input);
+}
+
+#endif /* CHECKSUM_FUNC_HPP */
diff --git a/src/core/random_func.hpp b/src/core/random_func.hpp
index 934703d6fb..d65060ccb7 100644
--- a/src/core/random_func.hpp
+++ b/src/core/random_func.hpp
@@ -12,6 +12,8 @@
#ifndef RANDOM_FUNC_HPP
#define RANDOM_FUNC_HPP
+#include "bitmath_func.hpp"
+
#if defined(__APPLE__)
/* Apple already has Random declared */
#define Random OTTD_Random
diff --git a/src/disaster_vehicle.cpp b/src/disaster_vehicle.cpp
index 2d52609dd3..ba5f30428d 100644
--- a/src/disaster_vehicle.cpp
+++ b/src/disaster_vehicle.cpp
@@ -47,6 +47,7 @@
#include "company_base.h"
#include "core/random_func.hpp"
#include "core/backup_type.hpp"
+#include "core/checksum_func.hpp"
#include "table/strings.h"
@@ -707,6 +708,7 @@ static DisasterVehicleTickProc * const _disastervehicle_tick_procs[] = {
bool DisasterVehicle::Tick()
{
+ UpdateStateChecksum((((uint64) this->x_pos) << 32) | this->y_pos);
return _disastervehicle_tick_procs[this->subtype](this);
}
diff --git a/src/effectvehicle.cpp b/src/effectvehicle.cpp
index 5ea274db69..bee23ac373 100644
--- a/src/effectvehicle.cpp
+++ b/src/effectvehicle.cpp
@@ -18,6 +18,7 @@
#include "animated_tile_func.h"
#include "effectvehicle_func.h"
#include "effectvehicle_base.h"
+#include "core/checksum_func.hpp"
#include
@@ -670,6 +671,7 @@ EffectVehicle *CreateEffectVehicleRel(const Vehicle *v, int x, int y, int z, Eff
bool EffectVehicle::Tick()
{
+ UpdateStateChecksum((((uint64) this->x_pos) << 32) | this->y_pos);
return _effect_tick_procs[this->subtype](this);
}
diff --git a/src/network/network.cpp b/src/network/network.cpp
index e705d74ba5..43e1922a3d 100644
--- a/src/network/network.cpp
+++ b/src/network/network.cpp
@@ -35,6 +35,7 @@
#include "../core/pool_func.hpp"
#include "../gfx_func.h"
#include "../error.h"
+#include "../core/checksum_func.hpp"
#include "../safeguards.h"
@@ -74,6 +75,7 @@ uint32 _sync_seed_1; ///< Seed to compare during sync checks.
#ifdef NETWORK_SEND_DOUBLE_SEED
uint32 _sync_seed_2; ///< Second part of the seed.
#endif
+uint64 _sync_state_checksum; ///< State checksum to compare during sync checks.
uint32 _sync_frame; ///< The frame to perform the sync check.
bool _network_first_time; ///< Whether we have finished joining or not.
bool _network_udp_server; ///< Is the UDP server started?
@@ -1028,6 +1030,7 @@ void NetworkGameLoop()
#ifdef NETWORK_SEND_DOUBLE_SEED
_sync_seed_2 = _random.state[1];
#endif
+ _sync_state_checksum = _state_checksum.state;
NetworkServer_Tick(send_frame);
} else {
diff --git a/src/network/network_client.cpp b/src/network/network_client.cpp
index f7d779b9d7..dc03be2aff 100644
--- a/src/network/network_client.cpp
+++ b/src/network/network_client.cpp
@@ -32,6 +32,7 @@
#include "../core/backup_type.hpp"
#include "../thread.h"
#include "../crashlog.h"
+#include "../core/checksum_func.hpp"
#include "table/strings.h"
@@ -282,9 +283,9 @@ void ClientNetworkGameSocketHandler::ClientError(NetworkRecvStatus res)
if (_sync_frame != 0) {
if (_sync_frame == _frame_counter) {
#ifdef NETWORK_SEND_DOUBLE_SEED
- if (_sync_seed_1 != _random.state[0] || _sync_seed_2 != _random.state[1]) {
+ if (_sync_seed_1 != _random.state[0] || _sync_seed_2 != _random.state[1] || _sync_state_checksum != _state_checksum.state) {
#else
- if (_sync_seed_1 != _random.state[0]) {
+ if (_sync_seed_1 != _random.state[0] || _sync_state_checksum != _state_checksum.state) {
#endif
NetworkError(STR_NETWORK_ERROR_DESYNC);
DEBUG(desync, 1, "sync_err: date{%08x; %02x; %02x}", _date, _date_fract, _tick_skip_counter);
@@ -945,6 +946,7 @@ NetworkRecvStatus ClientNetworkGameSocketHandler::Receive_SERVER_FRAME(Packet *p
#ifdef NETWORK_SEND_DOUBLE_SEED
_sync_seed_2 = p->Recv_uint32();
#endif
+ _sync_state_checksum = p->Recv_uint64();
}
#endif
/* Receive the token. */
@@ -972,6 +974,7 @@ NetworkRecvStatus ClientNetworkGameSocketHandler::Receive_SERVER_SYNC(Packet *p)
#ifdef NETWORK_SEND_DOUBLE_SEED
_sync_seed_2 = p->Recv_uint32();
#endif
+ _sync_state_checksum = p->Recv_uint64();
return NETWORK_RECV_STATUS_OKAY;
}
diff --git a/src/network/network_internal.h b/src/network/network_internal.h
index 73a8a56947..85b16923c7 100644
--- a/src/network/network_internal.h
+++ b/src/network/network_internal.h
@@ -118,6 +118,7 @@ extern uint32 _sync_seed_1;
#ifdef NETWORK_SEND_DOUBLE_SEED
extern uint32 _sync_seed_2;
#endif
+extern uint64 _sync_state_checksum;
extern uint32 _sync_frame;
extern bool _network_first_time;
/* Vars needed for the join-GUI */
diff --git a/src/network/network_server.cpp b/src/network/network_server.cpp
index 1265bb6cf1..0ff9f53e95 100644
--- a/src/network/network_server.cpp
+++ b/src/network/network_server.cpp
@@ -689,6 +689,7 @@ NetworkRecvStatus ServerNetworkGameSocketHandler::SendFrame()
#ifdef NETWORK_SEND_DOUBLE_SEED
p->Send_uint32(_sync_seed_2);
#endif
+ p->Send_uint64(_sync_state_checksum);
#endif
/* If token equals 0, we need to make a new token and send that. */
@@ -711,6 +712,7 @@ NetworkRecvStatus ServerNetworkGameSocketHandler::SendSync()
#ifdef NETWORK_SEND_DOUBLE_SEED
p->Send_uint32(_sync_seed_2);
#endif
+ p->Send_uint64(_sync_state_checksum);
this->SendPacket(p);
return NETWORK_RECV_STATUS_OKAY;
}
diff --git a/src/openttd.cpp b/src/openttd.cpp
index 88a100ae5b..2be27d8e82 100644
--- a/src/openttd.cpp
+++ b/src/openttd.cpp
@@ -77,6 +77,7 @@
#include "string_func_extra.h"
#include "industry.h"
#include "cargopacket.h"
+#include "core/checksum_func.hpp"
#include "linkgraph/linkgraphschedule.h"
#include "tracerestrict.h"
@@ -103,6 +104,8 @@ GameEventFlags _game_events_overall;
time_t _game_load_time;
+SimpleChecksum64 _state_checksum;
+
/**
* Error handling for fatal user errors.
* @param s the string to print.
@@ -1749,6 +1752,11 @@ void StateGameLoop()
CallWindowGameTickEvent();
NewsLoop();
cur_company.Restore();
+
+ Company *c;
+ FOR_ALL_COMPANIES(c) {
+ UpdateStateChecksum(c->money);
+ }
}
assert(IsLocalCompany());
diff --git a/src/roadveh_cmd.cpp b/src/roadveh_cmd.cpp
index 746b5786ce..d26e5217ca 100644
--- a/src/roadveh_cmd.cpp
+++ b/src/roadveh_cmd.cpp
@@ -39,6 +39,7 @@
#include "framerate_type.h"
#include "scope_info.h"
#include "string_func.h"
+#include "core/checksum_func.hpp"
#include "table/strings.h"
@@ -1061,6 +1062,7 @@ static Trackdir RoadFindPathToDest(RoadVehicle *v, TileIndex tile, DiagDirection
default: NOT_REACHED();
}
+ UpdateStateChecksum((((uint64) v->index) << 32) | (path_found << 16) | best_track);
v->HandlePathfindingResult(path_found);
found_best_track:;
@@ -1726,6 +1728,8 @@ Money RoadVehicle::GetRunningCost() const
bool RoadVehicle::Tick()
{
+ UpdateStateChecksum((((uint64) this->x_pos) << 32) | this->y_pos);
+ UpdateStateChecksum((((uint64) this->state) << 32) | this->frame);
if (this->IsFrontEngine()) {
if (!(this->IsRoadVehicleStopped())) this->running_ticks++;
return RoadVehController(this);
diff --git a/src/saveload/extended_ver_sl.cpp b/src/saveload/extended_ver_sl.cpp
index afdab325fb..377f507635 100644
--- a/src/saveload/extended_ver_sl.cpp
+++ b/src/saveload/extended_ver_sl.cpp
@@ -108,6 +108,7 @@ const SlxiSubChunkInfo _sl_xv_sub_chunk_infos[] = {
{ XSLFI_GAME_EVENTS, XSCF_NULL, 1, 1, "game_events", nullptr, nullptr, nullptr },
{ XSLFI_ROAD_LAYOUT_CHANGE_CTR, XSCF_NULL, 1, 1, "road_layout_change_ctr", nullptr, nullptr, nullptr },
{ XSLFI_TOWN_CARGO_MATRIX, XSCF_NULL, 1, 1, "town_cargo_matrix", nullptr, nullptr, nullptr },
+ { XSLFI_STATE_CHECKSUM, XSCF_NULL, 1, 1, "state_checksum", nullptr, nullptr, nullptr },
{ XSLFI_DEBUG, XSCF_IGNORABLE_ALL, 1, 1, "debug", nullptr, nullptr, "DBGL" },
{ XSLFI_NULL, XSCF_NULL, 0, 0, nullptr, nullptr, nullptr, nullptr },// This is the end marker
};
diff --git a/src/saveload/extended_ver_sl.h b/src/saveload/extended_ver_sl.h
index 2011fab96a..a52e0c955a 100644
--- a/src/saveload/extended_ver_sl.h
+++ b/src/saveload/extended_ver_sl.h
@@ -75,6 +75,7 @@ enum SlXvFeatureIndex {
XSLFI_GAME_EVENTS, ///< Game event flags
XSLFI_ROAD_LAYOUT_CHANGE_CTR, ///< Road layout change counter
XSLFI_TOWN_CARGO_MATRIX, ///< Town cargo matrix savegame format changes
+ XSLFI_STATE_CHECKSUM, ///< State checksum
XSLFI_DEBUG, ///< Debugging info
XSLFI_RIFF_HEADER_60_BIT, ///< Size field in RIFF chunk header is 60 bit
diff --git a/src/saveload/misc_sl.cpp b/src/saveload/misc_sl.cpp
index 77167d08d6..a6eee84661 100644
--- a/src/saveload/misc_sl.cpp
+++ b/src/saveload/misc_sl.cpp
@@ -19,6 +19,7 @@
#include "../core/random_func.hpp"
#include "../fios.h"
#include "../road_type.h"
+#include "../core/checksum_func.hpp"
#include "saveload.h"
@@ -86,6 +87,7 @@ static const SaveLoadGlobVarList _date_desc[] = {
SLE_CONDNULL(2, SL_MIN_VERSION, SLV_120),
SLEG_VAR(_random.state[0], SLE_UINT32),
SLEG_VAR(_random.state[1], SLE_UINT32),
+ SLEG_CONDVAR_X(_state_checksum.state, SLE_UINT64, SL_MIN_VERSION, SL_MAX_VERSION, SlXvFeatureTest(XSLFTO_AND, XSLFI_STATE_CHECKSUM)),
SLE_CONDNULL(1, SL_MIN_VERSION, SLV_10),
SLE_CONDNULL(4, SLV_10, SLV_120),
SLEG_VAR(_cur_company_tick_index, SLE_FILE_U8 | SLE_VAR_U32),
@@ -114,6 +116,7 @@ static const SaveLoadGlobVarList _date_check_desc[] = {
SLE_CONDNULL(2, SL_MIN_VERSION, SLV_120),
SLE_NULL(4), // _random.state[0]
SLE_NULL(4), // _random.state[1]
+ SLE_CONDNULL_X(8, SL_MIN_VERSION, SL_MAX_VERSION, SlXvFeatureTest(XSLFTO_AND, XSLFI_STATE_CHECKSUM)), // _state_checksum.state
SLE_CONDNULL(1, SL_MIN_VERSION, SLV_10),
SLE_CONDNULL(4, SLV_10, SLV_120),
SLE_NULL(1), // _cur_company_tick_index
diff --git a/src/ship_cmd.cpp b/src/ship_cmd.cpp
index 2ecde98843..45c33414e3 100644
--- a/src/ship_cmd.cpp
+++ b/src/ship_cmd.cpp
@@ -36,6 +36,7 @@
#include "tunnelbridge_map.h"
#include "zoom_func.h"
#include "framerate_type.h"
+#include "core/checksum_func.hpp"
#include "table/strings.h"
@@ -523,6 +524,7 @@ static Track ChooseShipTrack(Ship *v, TileIndex tile, DiagDirection enterdir, Tr
default: NOT_REACHED();
}
}
+ UpdateStateChecksum((((uint64) v->index) << 32) | (path_found << 16) | track);
v->HandlePathfindingResult(path_found);
return track;
@@ -948,6 +950,7 @@ reverse_direction:
bool Ship::Tick()
{
+ UpdateStateChecksum((((uint64) this->x_pos) << 32) | this->y_pos);
if (!(this->vehstatus & VS_STOPPED)) this->running_ticks++;
ShipController(this);
diff --git a/src/train_cmd.cpp b/src/train_cmd.cpp
index 2a146dc2a6..071d78acd3 100644
--- a/src/train_cmd.cpp
+++ b/src/train_cmd.cpp
@@ -43,6 +43,7 @@
#include "engine_func.h"
#include "bridge_signal_map.h"
#include "scope_info.h"
+#include "core/checksum_func.hpp"
#include "table/strings.h"
#include "table/train_cmd.h"
@@ -3127,6 +3128,7 @@ static Track ChooseTrainTrack(Train *v, TileIndex tile, DiagDirection enterdir,
TileIndex new_tile = res_dest.tile;
Track next_track = DoTrainPathfind(v, new_tile, dest_enterdir, tracks, path_found, do_track_reservation, &res_dest);
+ UpdateStateChecksum((((uint64) v->index) << 32) | (path_found << 16) | next_track);
if (new_tile == tile) best_track = next_track;
v->HandlePathfindingResult(path_found);
}
@@ -4971,6 +4973,7 @@ Money Train::GetRunningCost() const
*/
bool Train::Tick()
{
+ UpdateStateChecksum((((uint64) this->x_pos) << 32) | (this->y_pos << 16) | this->track );
if (this->IsFrontEngine()) {
if (!(this->vehstatus & VS_STOPPED) || this->cur_speed > 0) this->running_ticks++;