/* * Copyright (c) Contributors, http://opensimulator.org/ * See CONTRIBUTORS.TXT for a full list of copyright holders. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions are met: * * Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * * Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * Neither the name of the OpenSimulator Project nor the * names of its contributors may be used to endorse or promote products * derived from this software without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE DEVELOPERS ``AS IS'' AND ANY * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE * DISCLAIMED. IN NO EVENT SHALL THE CONTRIBUTORS BE LIABLE FOR ANY * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */ using System; using System.Collections.Generic; using System.Net; using System.Net.Sockets; using System.Reflection; using System.Threading; using log4net; using Nini.Config; using OpenMetaverse.Packets; using OpenSim.Framework; using OpenSim.Framework.Statistics; using OpenSim.Region.Framework.Scenes; using OpenMetaverse; namespace OpenSim.Region.ClientStack.LindenUDP { /// <summary> /// A shim around LLUDPServer that implements the IClientNetworkServer interface /// </summary> public sealed class LLUDPServerShim : IClientNetworkServer { LLUDPServer m_udpServer; public LLUDPServerShim() { } public void Initialise(IPAddress listenIP, ref uint port, int proxyPortOffsetParm, bool allow_alternate_port, IConfigSource configSource, AgentCircuitManager circuitManager) { m_udpServer = new LLUDPServer(listenIP, ref port, proxyPortOffsetParm, allow_alternate_port, configSource, circuitManager); } public void NetworkStop() { m_udpServer.Stop(); } public void AddScene(IScene scene) { m_udpServer.AddScene(scene); } public bool HandlesRegion(Location x) { return m_udpServer.HandlesRegion(x); } public void Start() { m_udpServer.Start(); } public void Stop() { m_udpServer.Stop(); } } /// <summary> /// The LLUDP server for a region. This handles incoming and outgoing /// packets for all UDP connections to the region /// </summary> public class LLUDPServer : OpenSimUDPBase { /// <summary>Maximum transmission unit, or UDP packet size, for the LLUDP protocol</summary> public const int MTU = 1400; private static readonly ILog m_log = LogManager.GetLogger(MethodBase.GetCurrentMethod().DeclaringType); /// <summary>Handlers for incoming packets</summary> //PacketEventDictionary packetEvents = new PacketEventDictionary(); /// <summary>Incoming packets that are awaiting handling</summary> private OpenMetaverse.BlockingQueue<IncomingPacket> packetInbox = new OpenMetaverse.BlockingQueue<IncomingPacket>(); /// <summary></summary> //private UDPClientCollection m_clients = new UDPClientCollection(); /// <summary>Bandwidth throttle for this UDP server</summary> private TokenBucket m_throttle; /// <summary>Bandwidth throttle rates for this UDP server</summary> private ThrottleRates m_throttleRates; /// <summary>Manages authentication for agent circuits</summary> private AgentCircuitManager m_circuitManager; /// <summary>Reference to the scene this UDP server is attached to</summary> private IScene m_scene; /// <summary>The X/Y coordinates of the scene this UDP server is attached to</summary> private Location m_location; /// <summary>The measured resolution of Environment.TickCount</summary> private float m_tickCountResolution; /// <summary>The size of the receive buffer for the UDP socket. This value /// is passed up to the operating system and used in the system networking /// stack. Use zero to leave this value as the default</summary> private int m_recvBufferSize; /// <summary>Flag to process packets asynchronously or synchronously</summary> private bool m_asyncPacketHandling; /// <summary>The measured resolution of Environment.TickCount</summary> public float TickCountResolution { get { return m_tickCountResolution; } } public Socket Server { get { return null; } } public LLUDPServer(IPAddress listenIP, ref uint port, int proxyPortOffsetParm, bool allow_alternate_port, IConfigSource configSource, AgentCircuitManager circuitManager) : base(listenIP, (int)port) { #region Environment.TickCount Measurement // Measure the resolution of Environment.TickCount m_tickCountResolution = 0f; for (int i = 0; i < 5; i++) { int start = Environment.TickCount; int now = start; while (now == start) now = Environment.TickCount; m_tickCountResolution += (float)(now - start) * 0.2f; } m_log.Info("[LLUDPSERVER]: Average Environment.TickCount resolution: " + TickCountResolution + "ms"); #endregion Environment.TickCount Measurement m_circuitManager = circuitManager; int sceneThrottleBps = 0; IConfig config = configSource.Configs["ClientStack.LindenUDP"]; if (config != null) { m_asyncPacketHandling = config.GetBoolean("async_packet_handling", false); m_recvBufferSize = config.GetInt("client_socket_rcvbuf_size", 0); sceneThrottleBps = config.GetInt("scene_throttle_max_bps", 0); } m_throttle = new TokenBucket(null, sceneThrottleBps, sceneThrottleBps); m_throttleRates = new ThrottleRates(configSource); } public void Start() { if (m_scene == null) throw new InvalidOperationException("[LLUDPSERVER]: Cannot LLUDPServer.Start() without an IScene reference"); m_log.Info("[LLUDPSERVER]: Starting the LLUDP server in " + (m_asyncPacketHandling ? "asynchronous" : "synchronous") + " mode"); base.Start(m_recvBufferSize, m_asyncPacketHandling); // Start the incoming packet processing thread Thread incomingThread = new Thread(IncomingPacketHandler); incomingThread.Name = "Incoming Packets (" + m_scene.RegionInfo.RegionName + ")"; incomingThread.Start(); Thread outgoingThread = new Thread(OutgoingPacketHandler); outgoingThread.Name = "Outgoing Packets (" + m_scene.RegionInfo.RegionName + ")"; outgoingThread.Start(); } public new void Stop() { m_log.Info("[LLUDPSERVER]: Shutting down the LLUDP server for " + m_scene.RegionInfo.RegionName); base.Stop(); } public void AddScene(IScene scene) { if (m_scene == null) { m_scene = scene; m_location = new Location(m_scene.RegionInfo.RegionHandle); } else { m_log.Error("[LLUDPSERVER]: AddScene() called on an LLUDPServer that already has a scene"); } } public bool HandlesRegion(Location x) { return x == m_location; } public void BroadcastPacket(Packet packet, ThrottleOutPacketType category, bool sendToPausedAgents, bool allowSplitting) { // CoarseLocationUpdate packets cannot be split in an automated way if (packet.Type == PacketType.CoarseLocationUpdate && allowSplitting) allowSplitting = false; if (allowSplitting && packet.HasVariableBlocks) { byte[][] datas = packet.ToBytesMultiple(); int packetCount = datas.Length; //if (packetCount > 1) // m_log.Debug("[LLUDPSERVER]: Split " + packet.Type + " packet into " + packetCount + " packets"); for (int i = 0; i < packetCount; i++) { byte[] data = datas[i]; m_scene.ClientManager.ForEach( delegate(IClientAPI client) { if (client is LLClientView) SendPacketData(((LLClientView)client).UDPClient, data, packet.Type, category); } ); } } else { byte[] data = packet.ToBytes(); m_scene.ClientManager.ForEach( delegate(IClientAPI client) { if (client is LLClientView) SendPacketData(((LLClientView)client).UDPClient, data, packet.Type, category); } ); } } public void SendPacket(LLUDPClient udpClient, Packet packet, ThrottleOutPacketType category, bool allowSplitting) { // CoarseLocationUpdate packets cannot be split in an automated way if (packet.Type == PacketType.CoarseLocationUpdate && allowSplitting) allowSplitting = false; if (allowSplitting && packet.HasVariableBlocks) { byte[][] datas = packet.ToBytesMultiple(); int packetCount = datas.Length; //if (packetCount > 1) // m_log.Debug("[LLUDPSERVER]: Split " + packet.Type + " packet into " + packetCount + " packets"); for (int i = 0; i < packetCount; i++) { byte[] data = datas[i]; SendPacketData(udpClient, data, packet.Type, category); } } else { byte[] data = packet.ToBytes(); SendPacketData(udpClient, data, packet.Type, category); } } public void SendPacketData(LLUDPClient udpClient, byte[] data, PacketType type, ThrottleOutPacketType category) { int dataLength = data.Length; bool doZerocode = (data[0] & Helpers.MSG_ZEROCODED) != 0; bool doCopy = true; // Frequency analysis of outgoing packet sizes shows a large clump of packets at each end of the spectrum. // The vast majority of packets are less than 200 bytes, although due to asset transfers and packet splitting // there are a decent number of packets in the 1000-1140 byte range. We allocate one of two sizes of data here // to accomodate for both common scenarios and provide ample room for ACK appending in both int bufferSize = (dataLength > 180) ? LLUDPServer.MTU : 200; UDPPacketBuffer buffer = new UDPPacketBuffer(udpClient.RemoteEndPoint, bufferSize); // Zerocode if needed if (doZerocode) { try { dataLength = Helpers.ZeroEncode(data, dataLength, buffer.Data); doCopy = false; } catch (IndexOutOfRangeException) { // The packet grew larger than the bufferSize while zerocoding. // Remove the MSG_ZEROCODED flag and send the unencoded data // instead m_log.Debug("[LLUDPSERVER]: Packet exceeded buffer size during zerocoding for " + type + ". DataLength=" + dataLength + " and BufferLength=" + buffer.Data.Length + ". Removing MSG_ZEROCODED flag"); data[0] = (byte)(data[0] & ~Helpers.MSG_ZEROCODED); } } // If the packet data wasn't already copied during zerocoding, copy it now if (doCopy) { if (dataLength <= buffer.Data.Length) { Buffer.BlockCopy(data, 0, buffer.Data, 0, dataLength); } else { m_log.Error("[LLUDPSERVER]: Packet exceeded buffer size! This could be an indication of packet assembly not obeying the MTU. Type=" + type + ", DataLength=" + dataLength + ", BufferLength=" + buffer.Data.Length + ". Dropping packet"); return; } } buffer.DataLength = dataLength; #region Queue or Send OutgoingPacket outgoingPacket = new OutgoingPacket(udpClient, buffer, category); if (!outgoingPacket.Client.EnqueueOutgoing(outgoingPacket)) SendPacketFinal(outgoingPacket); #endregion Queue or Send } public void SendAcks(LLUDPClient udpClient) { uint ack; if (udpClient.PendingAcks.Dequeue(out ack)) { List<PacketAckPacket.PacketsBlock> blocks = new List<PacketAckPacket.PacketsBlock>(); PacketAckPacket.PacketsBlock block = new PacketAckPacket.PacketsBlock(); block.ID = ack; blocks.Add(block); while (udpClient.PendingAcks.Dequeue(out ack)) { block = new PacketAckPacket.PacketsBlock(); block.ID = ack; blocks.Add(block); } PacketAckPacket packet = new PacketAckPacket(); packet.Header.Reliable = false; packet.Packets = blocks.ToArray(); SendPacket(udpClient, packet, ThrottleOutPacketType.Unknown, true); } } public void SendPing(LLUDPClient udpClient) { StartPingCheckPacket pc = (StartPingCheckPacket)PacketPool.Instance.GetPacket(PacketType.StartPingCheck); pc.Header.Reliable = false; OutgoingPacket oldestPacket = udpClient.NeedAcks.GetOldest(); pc.PingID.PingID = (byte)udpClient.CurrentPingSequence++; pc.PingID.OldestUnacked = (oldestPacket != null) ? oldestPacket.SequenceNumber : 0; SendPacket(udpClient, pc, ThrottleOutPacketType.Unknown, false); } public void ResendUnacked(LLUDPClient udpClient) { if (udpClient.IsConnected && udpClient.NeedAcks.Count > 0) { // Disconnect an agent if no packets are received for some time //FIXME: Make 60 an .ini setting if (Environment.TickCount - udpClient.TickLastPacketReceived > 1000 * 60) { m_log.Warn("[LLUDPSERVER]: Ack timeout, disconnecting " + udpClient.AgentID); RemoveClient(udpClient); return; } // Get a list of all of the packets that have been sitting unacked longer than udpClient.RTO List<OutgoingPacket> expiredPackets = udpClient.NeedAcks.GetExpiredPackets(udpClient.RTO); if (expiredPackets != null) { // Resend packets for (int i = 0; i < expiredPackets.Count; i++) { OutgoingPacket outgoingPacket = expiredPackets[i]; //m_log.DebugFormat("[LLUDPSERVER]: Resending packet #{0} (attempt {1}), {2}ms have passed", // outgoingPacket.SequenceNumber, outgoingPacket.ResendCount, Environment.TickCount - outgoingPacket.TickCount); // Set the resent flag outgoingPacket.Buffer.Data[0] = (byte)(outgoingPacket.Buffer.Data[0] | Helpers.MSG_RESENT); outgoingPacket.Category = ThrottleOutPacketType.Resend; // The TickCount will be set to the current time when the packet // is actually sent out again outgoingPacket.TickCount = 0; // Bump up the resend count on this packet Interlocked.Increment(ref outgoingPacket.ResendCount); //Interlocked.Increment(ref Stats.ResentPackets); // Requeue or resend the packet if (!outgoingPacket.Client.EnqueueOutgoing(outgoingPacket)) SendPacketFinal(outgoingPacket); } } } } public void Flush(LLUDPClient udpClient) { // FIXME: Implement? } internal void SendPacketFinal(OutgoingPacket outgoingPacket) { UDPPacketBuffer buffer = outgoingPacket.Buffer; byte flags = buffer.Data[0]; bool isResend = (flags & Helpers.MSG_RESENT) != 0; bool isReliable = (flags & Helpers.MSG_RELIABLE) != 0; LLUDPClient udpClient = outgoingPacket.Client; if (!udpClient.IsConnected) return; // Keep track of when this packet was sent out (right now) outgoingPacket.TickCount = Environment.TickCount; #region ACK Appending int dataLength = buffer.DataLength; // Keep appending ACKs until there is no room left in the buffer or there are // no more ACKs to append uint ackCount = 0; uint ack; while (dataLength + 5 < buffer.Data.Length && udpClient.PendingAcks.Dequeue(out ack)) { Utils.UIntToBytesBig(ack, buffer.Data, dataLength); dataLength += 4; ++ackCount; } if (ackCount > 0) { // Set the last byte of the packet equal to the number of appended ACKs buffer.Data[dataLength++] = (byte)ackCount; // Set the appended ACKs flag on this packet buffer.Data[0] = (byte)(buffer.Data[0] | Helpers.MSG_APPENDED_ACKS); } buffer.DataLength = dataLength; #endregion ACK Appending #region Sequence Number Assignment if (!isResend) { // Not a resend, assign a new sequence number uint sequenceNumber = (uint)Interlocked.Increment(ref udpClient.CurrentSequence); Utils.UIntToBytesBig(sequenceNumber, buffer.Data, 1); outgoingPacket.SequenceNumber = sequenceNumber; if (isReliable) { // Add this packet to the list of ACK responses we are waiting on from the server udpClient.NeedAcks.Add(outgoingPacket); } } #endregion Sequence Number Assignment // Stats tracking Interlocked.Increment(ref udpClient.PacketsSent); if (isReliable) Interlocked.Add(ref udpClient.UnackedBytes, outgoingPacket.Buffer.DataLength); // Put the UDP payload on the wire AsyncBeginSend(buffer); } protected override void PacketReceived(UDPPacketBuffer buffer) { // Debugging/Profiling //try { Thread.CurrentThread.Name = "PacketReceived (" + m_scene.RegionInfo.RegionName + ")"; } //catch (Exception) { } LLUDPClient udpClient = null; Packet packet = null; int packetEnd = buffer.DataLength - 1; IPEndPoint address = (IPEndPoint)buffer.RemoteEndPoint; #region Decoding try { packet = Packet.BuildPacket(buffer.Data, ref packetEnd, // Only allocate a buffer for zerodecoding if the packet is zerocoded ((buffer.Data[0] & Helpers.MSG_ZEROCODED) != 0) ? new byte[4096] : null); } catch (MalformedDataException) { m_log.ErrorFormat("[LLUDPSERVER]: Malformed data, cannot parse packet from {0}:\n{1}", buffer.RemoteEndPoint, Utils.BytesToHexString(buffer.Data, buffer.DataLength, null)); } // Fail-safe check if (packet == null) { m_log.Warn("[LLUDPSERVER]: Couldn't build a message from incoming data " + buffer.DataLength + " bytes long from " + buffer.RemoteEndPoint); return; } #endregion Decoding #region Packet to Client Mapping // UseCircuitCode handling if (packet.Type == PacketType.UseCircuitCode) { AddNewClient((UseCircuitCodePacket)packet, (IPEndPoint)buffer.RemoteEndPoint); } // Determine which agent this packet came from IClientAPI client; if (!m_scene.ClientManager.TryGetValue(address, out client) || !(client is LLClientView)) { m_log.Debug("[LLUDPSERVER]: Received a " + packet.Type + " packet from an unrecognized source: " + address + " in " + m_scene.RegionInfo.RegionName + ", currently tracking " + m_scene.ClientManager.Count + " clients"); return; } udpClient = ((LLClientView)client).UDPClient; if (!udpClient.IsConnected) return; #endregion Packet to Client Mapping // Stats tracking Interlocked.Increment(ref udpClient.PacketsReceived); #region ACK Receiving int now = Environment.TickCount; udpClient.TickLastPacketReceived = now; // Handle appended ACKs if (packet.Header.AppendedAcks && packet.Header.AckList != null) { lock (udpClient.NeedAcks.SyncRoot) { for (int i = 0; i < packet.Header.AckList.Length; i++) AcknowledgePacket(udpClient, packet.Header.AckList[i], now, packet.Header.Resent); } } // Handle PacketAck packets if (packet.Type == PacketType.PacketAck) { PacketAckPacket ackPacket = (PacketAckPacket)packet; lock (udpClient.NeedAcks.SyncRoot) { for (int i = 0; i < ackPacket.Packets.Length; i++) AcknowledgePacket(udpClient, ackPacket.Packets[i].ID, now, packet.Header.Resent); } } #endregion ACK Receiving #region ACK Sending if (packet.Header.Reliable) udpClient.PendingAcks.Enqueue(packet.Header.Sequence); // This is a somewhat odd sequence of steps to pull the client.BytesSinceLastACK value out, // add the current received bytes to it, test if 2*MTU bytes have been sent, if so remove // 2*MTU bytes from the value and send ACKs, and finally add the local value back to // client.BytesSinceLastACK. Lockless thread safety int bytesSinceLastACK = Interlocked.Exchange(ref udpClient.BytesSinceLastACK, 0); bytesSinceLastACK += buffer.DataLength; if (bytesSinceLastACK > LLUDPServer.MTU * 2) { bytesSinceLastACK -= LLUDPServer.MTU * 2; SendAcks(udpClient); } Interlocked.Add(ref udpClient.BytesSinceLastACK, bytesSinceLastACK); #endregion ACK Sending #region Incoming Packet Accounting // Check the archive of received reliable packet IDs to see whether we already received this packet if (packet.Header.Reliable && !udpClient.PacketArchive.TryEnqueue(packet.Header.Sequence)) { if (packet.Header.Resent) m_log.Debug("[LLUDPSERVER]: Received a resend of already processed packet #" + packet.Header.Sequence + ", type: " + packet.Type); else m_log.Warn("[LLUDPSERVER]: Received a duplicate (not marked as resend) of packet #" + packet.Header.Sequence + ", type: " + packet.Type); // Avoid firing a callback twice for the same packet return; } #endregion Incoming Packet Accounting // Don't bother clogging up the queue with PacketAck packets that are already handled here if (packet.Type != PacketType.PacketAck) { // Inbox insertion packetInbox.Enqueue(new IncomingPacket(udpClient, packet)); } } protected override void PacketSent(UDPPacketBuffer buffer, int bytesSent) { } private bool IsClientAuthorized(UseCircuitCodePacket useCircuitCode, out AuthenticateResponse sessionInfo) { UUID agentID = useCircuitCode.CircuitCode.ID; UUID sessionID = useCircuitCode.CircuitCode.SessionID; uint circuitCode = useCircuitCode.CircuitCode.Code; sessionInfo = m_circuitManager.AuthenticateSession(sessionID, agentID, circuitCode); return sessionInfo.Authorised; } private void AddNewClient(UseCircuitCodePacket useCircuitCode, IPEndPoint remoteEndPoint) { UUID agentID = useCircuitCode.CircuitCode.ID; UUID sessionID = useCircuitCode.CircuitCode.SessionID; uint circuitCode = useCircuitCode.CircuitCode.Code; if (m_scene.RegionStatus != RegionStatus.SlaveScene) { AuthenticateResponse sessionInfo; if (IsClientAuthorized(useCircuitCode, out sessionInfo)) { AddClient(circuitCode, agentID, sessionID, remoteEndPoint, sessionInfo); } else { // Don't create circuits for unauthorized clients m_log.WarnFormat( "[LLUDPSERVER]: Connection request for client {0} connecting with unnotified circuit code {1} from {2}", useCircuitCode.CircuitCode.ID, useCircuitCode.CircuitCode.Code, remoteEndPoint); } } else { // Slave regions don't accept new clients m_log.Debug("[LLUDPSERVER]: Slave region " + m_scene.RegionInfo.RegionName + " ignoring UseCircuitCode packet"); } } private void AddClient(uint circuitCode, UUID agentID, UUID sessionID, IPEndPoint remoteEndPoint, AuthenticateResponse sessionInfo) { // Create the LLUDPClient LLUDPClient udpClient = new LLUDPClient(this, m_throttleRates, m_throttle, circuitCode, agentID, remoteEndPoint); if (!m_scene.ClientManager.ContainsKey(agentID)) { // Create the LLClientView LLClientView client = new LLClientView(remoteEndPoint, m_scene, this, udpClient, sessionInfo, agentID, sessionID, circuitCode); client.OnLogout += LogoutHandler; // Start the IClientAPI client.Start(); } else { m_log.WarnFormat("[LLUDPSERVER]: Ignoring a repeated UseCircuitCode from {0} at {1} for circuit {2}", udpClient.AgentID, remoteEndPoint, circuitCode); } } private void RemoveClient(LLUDPClient udpClient) { // Remove this client from the scene IClientAPI client; if (m_scene.ClientManager.TryGetValue(udpClient.AgentID, out client)) client.Close(); } private void AcknowledgePacket(LLUDPClient client, uint ack, int currentTime, bool fromResend) { OutgoingPacket ackedPacket; if (client.NeedAcks.RemoveUnsafe(ack, out ackedPacket) && !fromResend) { // Update stats Interlocked.Add(ref client.UnackedBytes, -ackedPacket.Buffer.DataLength); // Calculate the round-trip time for this packet and its ACK int rtt = currentTime - ackedPacket.TickCount; if (rtt > 0) client.UpdateRoundTrip(rtt); } } private void IncomingPacketHandler() { // Set this culture for the thread that incoming packets are received // on to en-US to avoid number parsing issues Culture.SetCurrentCulture(); IncomingPacket incomingPacket = null; while (base.IsRunning) { try { if (packetInbox.Dequeue(100, ref incomingPacket)) Util.FireAndForget(ProcessInPacket, incomingPacket); } catch (Exception ex) { m_log.Error("[LLUDPSERVER]: Error in the incoming packet handler loop: " + ex.Message, ex); } } if (packetInbox.Count > 0) m_log.Warn("[LLUDPSERVER]: IncomingPacketHandler is shutting down, dropping " + packetInbox.Count + " packets"); packetInbox.Clear(); } private void OutgoingPacketHandler() { // Set this culture for the thread that outgoing packets are sent // on to en-US to avoid number parsing issues Culture.SetCurrentCulture(); int now = Environment.TickCount; int elapsedMS = 0; int elapsed100MS = 0; int elapsed500MS = 0; while (base.IsRunning) { bool resendUnacked = false; bool sendAcks = false; bool sendPings = false; bool packetSent = false; elapsedMS += Environment.TickCount - now; // Check for pending outgoing resends every 100ms if (elapsedMS >= 100) { resendUnacked = true; elapsedMS -= 100; ++elapsed100MS; } // Check for pending outgoing ACKs every 500ms if (elapsed100MS >= 5) { sendAcks = true; elapsed100MS = 0; ++elapsed500MS; } // Send pings to clients every 5000ms if (elapsed500MS >= 10) { sendPings = true; elapsed500MS = 0; } m_scene.ClientManager.ForEach( delegate(IClientAPI client) { if (client is LLClientView) { LLUDPClient udpClient = ((LLClientView)client).UDPClient; if (udpClient.IsConnected) { if (udpClient.DequeueOutgoing()) packetSent = true; if (resendUnacked) ResendUnacked(udpClient); if (sendAcks) { SendAcks(udpClient); udpClient.SendPacketStats(); } if (sendPings) SendPing(udpClient); } } } ); if (!packetSent) Thread.Sleep(20); } } private void ProcessInPacket(object state) { IncomingPacket incomingPacket = (IncomingPacket)state; Packet packet = incomingPacket.Packet; LLUDPClient udpClient = incomingPacket.Client; IClientAPI client; // Sanity check if (packet == null || udpClient == null) { m_log.WarnFormat("[LLUDPSERVER]: Processing a packet with incomplete state. Packet=\"{0}\", UDPClient=\"{1}\"", packet, udpClient); } // Make sure this client is still alive if (m_scene.ClientManager.TryGetValue(udpClient.AgentID, out client)) { try { // Process this packet client.ProcessInPacket(packet); } catch (ThreadAbortException) { // If something is trying to abort the packet processing thread, take that as a hint that it's time to shut down m_log.Info("[LLUDPSERVER]: Caught a thread abort, shutting down the LLUDP server"); Stop(); } catch (Exception e) { // Don't let a failure in an individual client thread crash the whole sim. m_log.ErrorFormat("[LLUDPSERVER]: Client packet handler for {0} for packet {1} threw an exception", udpClient.AgentID, packet.Type); m_log.Error(e.Message, e); } } else { m_log.DebugFormat("[LLUDPSERVER]: Dropping incoming {0} packet for dead client {1}", packet.Type, udpClient.AgentID); } } private void LogoutHandler(IClientAPI client) { client.SendLogoutPacket(); if (client.IsActive) RemoveClient(((LLClientView)client).UDPClient); } } }