Preparing in battle udp tunnel on backend.

battle_srv/main.go

@@ -56,7 +56,7 @@ func main() {
 		}
 		Logger.Info("Listening and serving HTTP on", zap.Any("Conf.Sio.HostAndPort", Conf.Sio.HostAndPort))
 	}()
-	go startUdpServer()
+	go startGrandUdpServer()
 	var gracefulStop = make(chan os.Signal)
 	signal.Notify(gracefulStop, syscall.SIGTERM)
 	signal.Notify(gracefulStop, syscall.SIGINT)
@@ -118,7 +118,7 @@ func startScheduler() {
 	c.Start()
 }
 
-func startUdpServer() {
+func startGrandUdpServer() {
 	conn, err := net.ListenUDP("udp", &net.UDPAddr{
 		Port: Conf.Sio.UdpPort,
 		IP:   net.ParseIP(Conf.Sio.UdpHost),
@@ -127,8 +127,15 @@ func startUdpServer() {
 		panic(err)
 	}
 
-	defer conn.Close()
+	defer func() {
-	Logger.Info(fmt.Sprintf("Udp server started at %s", conn.LocalAddr().String()))
+		conn.Close()
+		if r := recover(); r != nil {
+			Logger.Error("`GrandUdpServer`, recovery spot#1, recovered from: ", zap.Any("panic", r))
+		}
+		Logger.Info(fmt.Sprintf("The `GrandUdpServer` is stopped"))
+	}()
+
+	Logger.Info(fmt.Sprintf("`GrandUdpServer` started at %s", conn.LocalAddr().String()))
 
 	for {
 		message := make([]byte, 2046)
@@ -136,7 +143,7 @@ func startUdpServer() {
 		if err != nil {
 			panic(err)
 		}
-		Logger.Info(fmt.Sprintf("received: %d bytes from %s\n", rlen, remote))
+		Logger.Info(fmt.Sprintf("`GrandUdpServer` received: %d bytes from %s\n", rlen, remote))
 		ws.HandleUdpHolePunchingForPlayer(message[0:rlen], remote)
 	}
 }

battle_srv/models/player.go

@@ -52,6 +52,7 @@ type Player struct {
 	AckingInputFrameId       int32
 
 	UdpAddr             *PeerUdpAddr
+	BattleUdpTunnelAddr *PeerUdpAddr
 }
 
 func ExistPlayerByName(name string) (bool, error) {

battle_srv/models/room.go

@@ -158,6 +158,9 @@ type Room struct {
 
 	rdfIdToActuallyUsedInput           map[int32]*pb.InputFrameDownsync
 	LastIndividuallyConfirmedInputList []uint64
+
+	BattleUdpTunnelLock sync.Mutex // Guards "startBattleUdpTunnel"
+	BattleUdpTunnel     *net.UDPConn
 }
 
 func (pR *Room) updateScore() {
@@ -179,6 +182,7 @@ func (pR *Room) AddPlayerIfPossible(pPlayerFromDbInit *Player, session *websocke
 	defer pR.onPlayerAdded(playerId)
 
 	pPlayerFromDbInit.UdpAddr = nil
+	pPlayerFromDbInit.BattleUdpTunnelAddr = nil
 	pPlayerFromDbInit.AckingFrameId = -1
 	pPlayerFromDbInit.AckingInputFrameId = -1
 	pPlayerFromDbInit.LastSentInputFrameId = MAGIC_LAST_SENT_INPUT_FRAME_ID_NORMAL_ADDED
@@ -219,6 +223,7 @@ func (pR *Room) ReAddPlayerIfPossible(pTmpPlayerInstance *Player, session *webso
 	defer pR.onPlayerReAdded(playerId)
 	pEffectiveInRoomPlayerInstance := pR.Players[playerId]
 	pEffectiveInRoomPlayerInstance.UdpAddr = nil
+	pEffectiveInRoomPlayerInstance.BattleUdpTunnelAddr = nil
 	pEffectiveInRoomPlayerInstance.AckingFrameId = -1
 	pEffectiveInRoomPlayerInstance.AckingInputFrameId = -1
 	pEffectiveInRoomPlayerInstance.LastSentInputFrameId = MAGIC_LAST_SENT_INPUT_FRAME_ID_READDED
@@ -666,6 +671,10 @@ func (pR *Room) StopBattleForSettlement() {
 	if RoomBattleStateIns.IN_BATTLE != pR.State {
 		return
 	}
+	pR.BattleUdpTunnelLock.Lock()
+	pR.BattleUdpTunnel.Close()
+	pR.BattleUdpTunnelLock.Unlock()
+
 	pR.State = RoomBattleStateIns.STOPPING_BATTLE_FOR_SETTLEMENT
 	Logger.Info("Stopping the `battleMainLoop` for:", zap.Any("roomId", pR.Id))
 	pR.RenderFrameId++
@@ -809,7 +818,7 @@ func (pR *Room) OnDismissed() {
 	pR.RollbackEstimatedDtNanos = 16666666 // A little smaller than the actual per frame time, just for logging FAST FRAME
 	dilutedServerFps := float64(58.0)      // Don't set this value too small, otherwise we might miss force confirmation needs for slow tickers!
 	pR.dilutedRollbackEstimatedDtNanos = int64(float64(pR.RollbackEstimatedDtNanos) * float64(serverFps) / dilutedServerFps)
-	pR.BattleDurationFrames = int32(60 * serverFps)
+	pR.BattleDurationFrames = int32(5 * serverFps)
 	pR.BattleDurationNanos = int64(pR.BattleDurationFrames) * (pR.RollbackEstimatedDtNanos + 1)
 	pR.InputFrameUpsyncDelayTolerance = battle.ConvertToNoDelayInputFrameId(pR.NstDelayFrames) - 1 // this value should be strictly smaller than (NstDelayFrames >> InputScaleFrames), otherwise "type#1 forceConfirmation" might become a lag avalanche
 	pR.MaxChasingRenderFramesPerUpdate = 9                                                         // Don't set this value too high to avoid exhausting frontend CPU within a single frame, roughly as the "turn-around frames to recover" is empirically OK
@@ -818,12 +827,16 @@ func (pR *Room) OnDismissed() {
 	pR.ForceAllResyncOnAnyActiveSlowTicker = true // See tradeoff discussion in "downsyncToAllPlayers"
 
 	pR.FrameDataLoggingEnabled = false // [WARNING] DON'T ENABLE ON LONG BATTLE DURATION! It consumes A LOT OF MEMORY!
+	pR.BattleUdpTunnelLock.Lock()
+	pR.BattleUdpTunnel = nil
+	pR.BattleUdpTunnelLock.Unlock()
 
 	pR.ChooseStage()
 	pR.EffectivePlayerCount = 0
 
 	// [WARNING] It's deliberately ordered such that "pR.State = RoomBattleStateIns.IDLE" is put AFTER all the refreshing operations above.
 	pR.State = RoomBattleStateIns.IDLE
+	go pR.startBattleUdpTunnel() // Would reassign "pR.BattleUdpTunnel"
 	pR.updateScore()
 
 	Logger.Info("The room is completely dismissed(all playerDownsyncChan closed):", zap.Any("roomId", pR.Id))
@@ -1356,13 +1369,13 @@ func (pR *Room) printBarrier(barrierCollider *resolv.Object) {
 }
 
 func (pR *Room) doBattleMainLoopPerTickBackendDynamicsWithProperLocking(prevRenderFrameId int32, pDynamicsDuration *int64) {
-	Logger.Debug(fmt.Sprintf("doBattleMainLoopPerTickBackendDynamicsWithProperLocking-InputsBufferLock to about lock: roomId=%v", pR.Id))
+	//Logger.Debug(fmt.Sprintf("doBattleMainLoopPerTickBackendDynamicsWithProperLocking-InputsBufferLock to about lock: roomId=%v", pR.Id))
 	pR.InputsBufferLock.Lock()
-	Logger.Debug(fmt.Sprintf("doBattleMainLoopPerTickBackendDynamicsWithProperLocking-InputsBufferLock locked: roomId=%v", pR.Id))
+	//Logger.Debug(fmt.Sprintf("doBattleMainLoopPerTickBackendDynamicsWithProperLocking-InputsBufferLock locked: roomId=%v", pR.Id))
 
 	defer func() {
 		pR.InputsBufferLock.Unlock()
-		Logger.Debug(fmt.Sprintf("doBattleMainLoopPerTickBackendDynamicsWithProperLocking-InputsBufferLock unlocked: roomId=%v", pR.Id))
+		//Logger.Debug(fmt.Sprintf("doBattleMainLoopPerTickBackendDynamicsWithProperLocking-InputsBufferLock unlocked: roomId=%v", pR.Id))
 	}()
 
 	if ok, thatRenderFrameId := battle.ShouldPrefabInputFrameDownsync(prevRenderFrameId, pR.RenderFrameId); ok {
@@ -1663,3 +1676,43 @@ func (pR *Room) UpdatePeerUdpAddrList(playerId int32, peerAddr *net.UDPAddr, pRe
 		}
 	}
 }
+
+func (pR *Room) startBattleUdpTunnel() {
+	defer func() {
+		if r := recover(); r != nil {
+			Logger.Error("`BattleUdpTunnel` recovery spot#1, recovered from: ", zap.Any("roomId", pR.Id), zap.Any("panic", r))
+		}
+		Logger.Info(fmt.Sprintf("`BattleUdpTunnel` stopped for (roomId=%d)@renderFrameId=%v", pR.Id, pR.RenderFrameId))
+	}()
+
+	pR.BattleUdpTunnelLock.Lock()
+	conn, err := net.ListenUDP("udp", &net.UDPAddr{
+		Port: 0,
+		IP:   net.ParseIP(Conf.Sio.UdpHost),
+	})
+	if nil != err {
+		// No need to close the "conn" upon error here
+		pR.BattleUdpTunnelLock.Unlock()
+		panic(err)
+	}
+	pR.BattleUdpTunnel = conn
+	pR.BattleUdpTunnelLock.Unlock()
+
+	defer func() {
+		if r := recover(); r != nil {
+			Logger.Warn("`BattleUdpTunnel` recovery spot#2, recovered from: ", zap.Any("roomId", pR.Id), zap.Any("panic", r))
+		}
+		Logger.Info(fmt.Sprintf("`BattleUdpTunnel` closed for (roomId=%d)@renderFrameId=%v", pR.Id, pR.RenderFrameId))
+	}()
+	Logger.Info(fmt.Sprintf("`BattleUdpTunnel` started for roomId=%d at %s", pR.Id, conn.LocalAddr().String()))
+	for {
+		message := make([]byte, 2046)
+		rlen, remote, err := conn.ReadFromUDP(message[:]) // Would be unblocked when "conn.Close()" is called from another thread/goroutine, reference https://pkg.go.dev/net@go1.18.6#PacketConn
+		if nil != err {
+			// Should proceed to close the "conn" upon error here, if "conn" is already closed it'd just throw another error to be catched by "spot#2"
+			conn.Close()
+			panic(err)
+		}
+		Logger.Info(fmt.Sprintf("`BattleUdpTunnel` for roomId=%d received %d bytes from %s\n", pR.Id, rlen, remote))
+	}
+}

frontend/assets/scenes/login.fire

@@ -461,7 +461,7 @@
       "array": [
         0,
         0,
-        209.6693197428241,
+        209.73151519075364,
         0,
         0,
         0,