6 files changed, 808 insertions, 141 deletions

diff --git a/OpenSim/Region/ClientStack/Linden/UDP/IncomingPacket.cs b/OpenSim/Region/ClientStack/Linden/UDP/IncomingPacket.cs
index 1b8535c..e22670b 100644
--- a/OpenSim/Region/ClientStack/Linden/UDP/IncomingPacket.cs
+++ b/OpenSim/Region/ClientStack/Linden/UDP/IncomingPacket.cs
@@ -45,7 +45,12 @@ namespace OpenSim.Region.ClientStack.LindenUDP
         public Packet Packet;
 
         /// <summary>
-        /// Default constructor
+        /// No arg constructor.
+        /// </summary>
+        public IncomingPacket() {}
+
+        /// <summary>
+        /// Constructor
         /// </summary>
         /// <param name="client">Reference to the client this packet came from</param>
         /// <param name="packet">Packet data</param>
diff --git a/OpenSim/Region/ClientStack/Linden/UDP/LLClientView.cs b/OpenSim/Region/ClientStack/Linden/UDP/LLClientView.cs
index ee28914..3c65647 100644
--- a/OpenSim/Region/ClientStack/Linden/UDP/LLClientView.cs
+++ b/OpenSim/Region/ClientStack/Linden/UDP/LLClientView.cs
@@ -47,6 +47,7 @@ using OpenSim.Region.Framework.Scenes;
 using OpenSim.Services.Interfaces;
 using Timer = System.Timers.Timer;
 using AssetLandmark = OpenSim.Framework.AssetLandmark;
+using RegionFlags = OpenMetaverse.RegionFlags;
 using Nini.Config;
 
 using System.IO;
@@ -354,7 +355,17 @@ namespace OpenSim.Region.ClientStack.LindenUDP
         private bool m_deliverPackets = true;
         private int m_animationSequenceNumber = 1;
         private bool m_SendLogoutPacketWhenClosing = true;
-        private AgentUpdateArgs lastarg;
+
+        /// <summary>
+        /// We retain a single AgentUpdateArgs so that we can constantly reuse it rather than construct a new one for
+        /// every single incoming AgentUpdate.  Every client sends 10 AgentUpdate UDP messages per second, even if it
+        /// is doing absolutely nothing.
+        /// </summary>
+        /// <remarks>
+        /// This does mean that agent updates must be processed synchronously, at least for each client, and called methods
+        /// cannot retain a reference to it outside of that method.
+        /// </remarks>
+        private AgentUpdateArgs m_lastAgentUpdateArgs;
 
         protected Dictionary<PacketType, PacketProcessor> m_packetHandlers = new Dictionary<PacketType, PacketProcessor>();
         protected Dictionary<string, GenericMessage> m_genericPacketHandlers = new Dictionary<string, GenericMessage>(); //PauPaw:Local Generic Message handlers
@@ -509,19 +520,18 @@ namespace OpenSim.Region.ClientStack.LindenUDP
         /// </summary>
         public void Close()
         {
-            Close(true);
+            Close(true, false);
         }
 
-        /// <summary>
-        /// Shut down the client view
-        /// </summary>
-        public void Close(bool sendStop)
+        public void Close(bool sendStop, bool force)
         {
             // We lock here to prevent race conditions between two threads calling close simultaneously (e.g.
             // a simultaneous relog just as a client is being closed out due to no packet ack from the old connection.
             lock (CloseSyncLock)
             {
-                if (!IsActive)
+                // We still perform a force close inside the sync lock since this is intended to attempt close where
+                // there is some unidentified connection problem, not where we have issues due to deadlock
+                if (!IsActive && !force)
                     return;
 
                 IsActive = false;
@@ -836,8 +846,9 @@ namespace OpenSim.Region.ClientStack.LindenUDP
             OutPacket(mov, ThrottleOutPacketType.Unknown);
         }
 
-        public void SendChatMessage(string message, byte type, Vector3 fromPos, string fromName,
-                                    UUID fromAgentID, byte source, byte audible)
+        public void SendChatMessage(
+            string message, byte type, Vector3 fromPos, string fromName,
+            UUID fromAgentID, UUID ownerID, byte source, byte audible)
         {
             ChatFromSimulatorPacket reply = (ChatFromSimulatorPacket)PacketPool.Instance.GetPacket(PacketType.ChatFromSimulator);
             reply.ChatData.Audible = audible;
@@ -846,7 +857,7 @@ namespace OpenSim.Region.ClientStack.LindenUDP
             reply.ChatData.SourceType = source;
             reply.ChatData.Position = fromPos;
             reply.ChatData.FromName = Util.StringToBytes256(fromName);
-            reply.ChatData.OwnerID = fromAgentID;
+            reply.ChatData.OwnerID = ownerID;
             reply.ChatData.SourceID = fromAgentID;
 
             OutPacket(reply, ThrottleOutPacketType.Unknown);
@@ -3984,7 +3995,8 @@ namespace OpenSim.Region.ClientStack.LindenUDP
             {
                 List<ImprovedTerseObjectUpdatePacket.ObjectDataBlock> blocks = terseAgentUpdateBlocks.Value;
 
-                ImprovedTerseObjectUpdatePacket packet = new ImprovedTerseObjectUpdatePacket();
+                ImprovedTerseObjectUpdatePacket packet
+                    = (ImprovedTerseObjectUpdatePacket)PacketPool.Instance.GetPacket(PacketType.ImprovedTerseObjectUpdate);
                 packet.RegionData.RegionHandle = m_scene.RegionInfo.RegionHandle;
                 packet.RegionData.TimeDilation = timeDilation;
                 packet.ObjectData = new ImprovedTerseObjectUpdatePacket.ObjectDataBlock[blocks.Count];
@@ -4029,7 +4041,9 @@ namespace OpenSim.Region.ClientStack.LindenUDP
             {
                 List<ImprovedTerseObjectUpdatePacket.ObjectDataBlock> blocks = terseUpdateBlocks.Value;
     
-                ImprovedTerseObjectUpdatePacket packet = new ImprovedTerseObjectUpdatePacket();
+                ImprovedTerseObjectUpdatePacket packet
+                    = (ImprovedTerseObjectUpdatePacket)PacketPool.Instance.GetPacket(
+                        PacketType.ImprovedTerseObjectUpdate);
                 packet.RegionData.RegionHandle = m_scene.RegionInfo.RegionHandle;
                 packet.RegionData.TimeDilation = timeDilation;
                 packet.ObjectData = new ImprovedTerseObjectUpdatePacket.ObjectDataBlock[blocks.Count];
@@ -4037,7 +4051,7 @@ namespace OpenSim.Region.ClientStack.LindenUDP
                 for (int i = 0; i < blocks.Count; i++)
                     packet.ObjectData[i] = blocks[i];
     
-                OutPacket(packet, ThrottleOutPacketType.Task, true);
+                OutPacket(packet, ThrottleOutPacketType.Task, true, delegate(OutgoingPacket oPacket) { ResendPrimUpdates(terseUpdates.Value, oPacket); });
             }
 
             #endregion Packet Sending
@@ -4534,7 +4548,7 @@ namespace OpenSim.Region.ClientStack.LindenUDP
                     {
                         returnblock[j] = new EstateOwnerMessagePacket.ParamListBlock();
                     }
-                    j = 0;
+                    j = 0; 
 
                     returnblock[j].Parameter = Utils.StringToBytes(estateID.ToString()); j++;
                     returnblock[j].Parameter = Utils.StringToBytes(((int)Constants.EstateAccessCodex.EstateBans).ToString()); j++;
@@ -5038,7 +5052,9 @@ namespace OpenSim.Region.ClientStack.LindenUDP
             Utils.UInt16ToBytes(Utils.FloatToUInt16(angularVelocity.Y, -64.0f, 64.0f), data, pos); pos += 2;
             Utils.UInt16ToBytes(Utils.FloatToUInt16(angularVelocity.Z, -64.0f, 64.0f), data, pos); pos += 2;
 
-            ImprovedTerseObjectUpdatePacket.ObjectDataBlock block = new ImprovedTerseObjectUpdatePacket.ObjectDataBlock();
+            ImprovedTerseObjectUpdatePacket.ObjectDataBlock block
+                = PacketPool.Instance.GetDataBlock<ImprovedTerseObjectUpdatePacket.ObjectDataBlock>();
+            
             block.Data = data;
 
             if (textureEntry != null && textureEntry.Length > 0)
@@ -5288,7 +5304,11 @@ namespace OpenSim.Region.ClientStack.LindenUDP
         protected virtual void RegisterLocalPacketHandlers()
         {
             AddLocalPacketHandler(PacketType.LogoutRequest, HandleLogout);
+
+            // If AgentUpdate is ever handled asynchronously, then we will also need to construct a new AgentUpdateArgs
+            // for each AgentUpdate packet.
             AddLocalPacketHandler(PacketType.AgentUpdate, HandleAgentUpdate, false);
+            
             AddLocalPacketHandler(PacketType.ViewerEffect, HandleViewerEffect, false);
             AddLocalPacketHandler(PacketType.AgentCachedTexture, HandleAgentTextureCached, false);
             AddLocalPacketHandler(PacketType.MultipleObjectUpdate, HandleMultipleObjUpdate, false);
@@ -5517,81 +5537,84 @@ namespace OpenSim.Region.ClientStack.LindenUDP
 
         #region Scene/Avatar
 
-        private bool HandleAgentUpdate(IClientAPI sener, Packet Pack)
+        private bool HandleAgentUpdate(IClientAPI sener, Packet packet)
         {
             if (OnAgentUpdate != null)
             {
-                bool update = false;
-                AgentUpdatePacket agenUpdate = (AgentUpdatePacket)Pack;
+                AgentUpdatePacket agentUpdate = (AgentUpdatePacket)packet;
 
                 #region Packet Session and User Check
-                if (agenUpdate.AgentData.SessionID != SessionId || agenUpdate.AgentData.AgentID != AgentId)
+                if (agentUpdate.AgentData.SessionID != SessionId || agentUpdate.AgentData.AgentID != AgentId)
+                {
+                    PacketPool.Instance.ReturnPacket(packet);
                     return false;
+                }
                 #endregion
 
-                AgentUpdatePacket.AgentDataBlock x = agenUpdate.AgentData;
-
-                // We can only check when we have something to check
-                // against.
+                bool update = false;
+                AgentUpdatePacket.AgentDataBlock x = agentUpdate.AgentData;
 
-                if (lastarg != null)
+                if (m_lastAgentUpdateArgs != null)
                 {
+                    // These should be ordered from most-likely to
+                    // least likely to change. I've made an initial
+                    // guess at that.
                     update =
                        (
-                        (x.BodyRotation != lastarg.BodyRotation) ||
-                        (x.CameraAtAxis != lastarg.CameraAtAxis) ||
-                        (x.CameraCenter != lastarg.CameraCenter) ||
-                        (x.CameraLeftAxis != lastarg.CameraLeftAxis) ||
-                        (x.CameraUpAxis != lastarg.CameraUpAxis) ||
-                        (x.ControlFlags != lastarg.ControlFlags) ||
+                        (x.BodyRotation != m_lastAgentUpdateArgs.BodyRotation) ||
+                        (x.CameraAtAxis != m_lastAgentUpdateArgs.CameraAtAxis) ||
+                        (x.CameraCenter != m_lastAgentUpdateArgs.CameraCenter) ||
+                        (x.CameraLeftAxis != m_lastAgentUpdateArgs.CameraLeftAxis) ||
+                        (x.CameraUpAxis != m_lastAgentUpdateArgs.CameraUpAxis) ||
+                        (x.ControlFlags != m_lastAgentUpdateArgs.ControlFlags) ||
                         (x.ControlFlags != 0) ||
-                        (x.Far != lastarg.Far) ||
-                        (x.Flags != lastarg.Flags) ||
-                        (x.State != lastarg.State) ||
-                        (x.HeadRotation != lastarg.HeadRotation) ||
-                        (x.SessionID != lastarg.SessionID) ||
-                        (x.AgentID != lastarg.AgentID)
+                        (x.Far != m_lastAgentUpdateArgs.Far) ||
+                        (x.Flags != m_lastAgentUpdateArgs.Flags) ||
+                        (x.State != m_lastAgentUpdateArgs.State) ||
+                        (x.HeadRotation != m_lastAgentUpdateArgs.HeadRotation) ||
+                        (x.SessionID != m_lastAgentUpdateArgs.SessionID) ||
+                        (x.AgentID != m_lastAgentUpdateArgs.AgentID)
                        );
                 }
                 else
                 {
+                    m_lastAgentUpdateArgs = new AgentUpdateArgs();
                     update = true;
                 }
 
-                // These should be ordered from most-likely to
-                // least likely to change. I've made an initial
-                // guess at that.
-
                 if (update)
                 {
 //                    m_log.DebugFormat("[LLCLIENTVIEW]: Triggered AgentUpdate for {0}", sener.Name);
 
-                    AgentUpdateArgs arg = new AgentUpdateArgs();
-                    arg.AgentID = x.AgentID;
-                    arg.BodyRotation = x.BodyRotation;
-                    arg.CameraAtAxis = x.CameraAtAxis;
-                    arg.CameraCenter = x.CameraCenter;
-                    arg.CameraLeftAxis = x.CameraLeftAxis;
-                    arg.CameraUpAxis = x.CameraUpAxis;
-                    arg.ControlFlags = x.ControlFlags;
-                    arg.Far = x.Far;
-                    arg.Flags = x.Flags;
-                    arg.HeadRotation = x.HeadRotation;
-                    arg.SessionID = x.SessionID;
-                    arg.State = x.State;
+                    m_lastAgentUpdateArgs.AgentID = x.AgentID;
+                    m_lastAgentUpdateArgs.BodyRotation = x.BodyRotation;
+                    m_lastAgentUpdateArgs.CameraAtAxis = x.CameraAtAxis;
+                    m_lastAgentUpdateArgs.CameraCenter = x.CameraCenter;
+                    m_lastAgentUpdateArgs.CameraLeftAxis = x.CameraLeftAxis;
+                    m_lastAgentUpdateArgs.CameraUpAxis = x.CameraUpAxis;
+                    m_lastAgentUpdateArgs.ControlFlags = x.ControlFlags;
+                    m_lastAgentUpdateArgs.Far = x.Far;
+                    m_lastAgentUpdateArgs.Flags = x.Flags;
+                    m_lastAgentUpdateArgs.HeadRotation = x.HeadRotation;
+                    m_lastAgentUpdateArgs.SessionID = x.SessionID;
+                    m_lastAgentUpdateArgs.State = x.State;
+
                     UpdateAgent handlerAgentUpdate = OnAgentUpdate;
                     UpdateAgent handlerPreAgentUpdate = OnPreAgentUpdate;
-                    lastarg = arg; // save this set of arguments for nexttime
+
                     if (handlerPreAgentUpdate != null)
-                        OnPreAgentUpdate(this, arg);
+                        OnPreAgentUpdate(this, m_lastAgentUpdateArgs);
+
                     if (handlerAgentUpdate != null)
-                        OnAgentUpdate(this, arg);
+                        OnAgentUpdate(this, m_lastAgentUpdateArgs);
 
                     handlerAgentUpdate = null;
                     handlerPreAgentUpdate = null;
                 }
             }
 
+            PacketPool.Instance.ReturnPacket(packet);
+
             return true;
         }
 
@@ -5963,7 +5986,8 @@ namespace OpenSim.Region.ClientStack.LindenUDP
                         msgpack.MessageBlock.ID,
                         msgpack.MessageBlock.Offline != 0 ? true : false,
                         msgpack.MessageBlock.Position,
-                        msgpack.MessageBlock.BinaryBucket);
+                        msgpack.MessageBlock.BinaryBucket,
+                        true);
 
                 handlerInstantMessage(this, im);
             }
@@ -9245,7 +9269,9 @@ namespace OpenSim.Region.ClientStack.LindenUDP
             }
             #endregion
 
-            switch (Utils.BytesToString(messagePacket.MethodData.Method))
+            string method = Utils.BytesToString(messagePacket.MethodData.Method);
+
+            switch (method)
             {
                 case "getinfo":
                     if (((Scene)m_scene).Permissions.CanIssueEstateCommand(AgentId, false))
@@ -9561,7 +9587,17 @@ namespace OpenSim.Region.ClientStack.LindenUDP
                     return true;
 
                 default:
-                    m_log.Error("EstateOwnerMessage: Unknown method requested\n" + messagePacket);
+                    m_log.WarnFormat(
+                        "[LLCLIENTVIEW]: EstateOwnerMessage: Unknown method {0} requested for {1} in {2}",
+                        method, Name, Scene.Name);
+
+                    for (int i = 0; i < messagePacket.ParamList.Length; i++)
+                    {
+                        EstateOwnerMessagePacket.ParamListBlock block = messagePacket.ParamList[i];
+                        string data = (string)Utils.BytesToString(block.Parameter);
+                        m_log.DebugFormat("[LLCLIENTVIEW]: Param {0}={1}", i, data);
+                    }
+
                     return true;
             }
 
@@ -11949,7 +11985,7 @@ namespace OpenSim.Region.ClientStack.LindenUDP
                     logPacket = false;
                 
                 if (DebugPacketLevel <= 50
-                    & (packet.Type == PacketType.ImprovedTerseObjectUpdate || packet.Type == PacketType.ObjectUpdate))
+                    && (packet.Type == PacketType.ImprovedTerseObjectUpdate || packet.Type == PacketType.ObjectUpdate))
                     logPacket = false;
 
                 if (DebugPacketLevel <= 25 && packet.Type == PacketType.ObjectPropertiesFamily)
@@ -12023,8 +12059,6 @@ namespace OpenSim.Region.ClientStack.LindenUDP
 
             if (!ProcessPacketMethod(packet))
                 m_log.Warn("[CLIENT]: unhandled packet " + packet.Type);
-
-            PacketPool.Instance.ReturnPacket(packet);
         }
 
         private static PrimitiveBaseShape GetShapeFromAddPacket(ObjectAddPacket addPacket)
@@ -12193,7 +12227,7 @@ namespace OpenSim.Region.ClientStack.LindenUDP
         {
             Kick(reason);
             Thread.Sleep(1000);
-            Close();
+            Disconnect();
         }
 
         public void Disconnect()
@@ -12481,7 +12515,10 @@ namespace OpenSim.Region.ClientStack.LindenUDP
                 ushort timeDilation = Utils.FloatToUInt16(TIME_DILATION, 0.0f, 1.0f);
 
 
-                ImprovedTerseObjectUpdatePacket packet = new ImprovedTerseObjectUpdatePacket();
+                ImprovedTerseObjectUpdatePacket packet
+                    = (ImprovedTerseObjectUpdatePacket)PacketPool.Instance.GetPacket(
+                        PacketType.ImprovedTerseObjectUpdate);
+
                 packet.RegionData.RegionHandle = m_scene.RegionInfo.RegionHandle;
                 packet.RegionData.TimeDilation = timeDilation;
                 packet.ObjectData = new ImprovedTerseObjectUpdatePacket.ObjectDataBlock[1];
diff --git a/OpenSim/Region/ClientStack/Linden/UDP/LLUDPServer.cs b/OpenSim/Region/ClientStack/Linden/UDP/LLUDPServer.cs
index d6513c5..b8951d9 100644
--- a/OpenSim/Region/ClientStack/Linden/UDP/LLUDPServer.cs
+++ b/OpenSim/Region/ClientStack/Linden/UDP/LLUDPServer.cs
@@ -37,6 +37,7 @@ using log4net;
 using Nini.Config;
 using OpenMetaverse.Packets;
 using OpenSim.Framework;
+using OpenSim.Framework.Console;
 using OpenSim.Framework.Monitoring;
 using OpenSim.Region.Framework.Scenes;
 using OpenMetaverse;
@@ -100,9 +101,11 @@ namespace OpenSim.Region.ClientStack.LindenUDP
 
         /// <summary>The measured resolution of Environment.TickCount</summary>
         public readonly float TickCountResolution;
+
         /// <summary>Number of prim updates to put on the queue each time the 
         /// OnQueueEmpty event is triggered for updates</summary>
         public readonly int PrimUpdatesPerCallback;
+
         /// <summary>Number of texture packets to put on the queue each time the
         /// OnQueueEmpty event is triggered for textures</summary>
         public readonly int TextureSendLimit;
@@ -124,28 +127,37 @@ namespace OpenSim.Region.ClientStack.LindenUDP
         
         /// <summary>Manages authentication for agent circuits</summary>
         private AgentCircuitManager m_circuitManager;
+
         /// <summary>Reference to the scene this UDP server is attached to</summary>
         protected Scene m_scene;
+
         /// <summary>The X/Y coordinates of the scene this UDP server is attached to</summary>
         private Location m_location;
+
         /// <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>Tracks whether or not a packet was sent each round so we know
         /// whether or not to sleep</summary>
         private bool m_packetSent;
 
         /// <summary>Environment.TickCount of the last time that packet stats were reported to the scene</summary>
         private int m_elapsedMSSinceLastStatReport = 0;
+
         /// <summary>Environment.TickCount of the last time the outgoing packet handler executed</summary>
         private int m_tickLastOutgoingPacketHandler;
+
         /// <summary>Keeps track of the number of elapsed milliseconds since the last time the outgoing packet handler looped</summary>
         private int m_elapsedMSOutgoingPacketHandler;
+
         /// <summary>Keeps track of the number of 100 millisecond periods elapsed in the outgoing packet handler executed</summary>
         private int m_elapsed100MSOutgoingPacketHandler;
+
         /// <summary>Keeps track of the number of 500 millisecond periods elapsed in the outgoing packet handler executed</summary>
         private int m_elapsed500MSOutgoingPacketHandler;
 
@@ -159,6 +171,9 @@ namespace OpenSim.Region.ClientStack.LindenUDP
         protected bool m_sendPing;
 
         private ExpiringCache<IPEndPoint, Queue<UDPPacketBuffer>> m_pendingCache = new ExpiringCache<IPEndPoint, Queue<UDPPacketBuffer>>();
+        private Pool<IncomingPacket> m_incomingPacketPool;
+
+        private Stat m_incomingPacketPoolStat;
 
         private int m_defaultRTO = 0;
         private int m_maxRTO = 0;
@@ -180,7 +195,9 @@ namespace OpenSim.Region.ClientStack.LindenUDP
         /// </summary>
         private IClientAPI m_currentIncomingClient;
 
-        public LLUDPServer(IPAddress listenIP, ref uint port, int proxyPortOffsetParm, bool allow_alternate_port, IConfigSource configSource, AgentCircuitManager circuitManager)
+        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
@@ -202,6 +219,7 @@ namespace OpenSim.Region.ClientStack.LindenUDP
 
             m_circuitManager = circuitManager;
             int sceneThrottleBps = 0;
+            bool usePools = false;
 
             IConfig config = configSource.Configs["ClientStack.LindenUDP"];
             if (config != null)
@@ -227,6 +245,16 @@ namespace OpenSim.Region.ClientStack.LindenUDP
                 m_pausedAckTimeout = 1000 * 300; // 5 minutes
             }
 
+            // FIXME: This actually only needs to be done once since the PacketPool is shared across all servers.
+            // However, there is no harm in temporarily doing it multiple times.
+            IConfig packetConfig = configSource.Configs["PacketPool"];
+            if (packetConfig != null)
+            {
+                PacketPool.Instance.RecyclePackets = packetConfig.GetBoolean("RecyclePackets", true);
+                PacketPool.Instance.RecycleDataBlocks = packetConfig.GetBoolean("RecycleDataBlocks", true);
+                usePools = packetConfig.GetBoolean("RecycleBaseUDPPackets", usePools);
+            }
+
             #region BinaryStats
             config = configSource.Configs["Statistics.Binary"];
             m_shouldCollectStats = false;
@@ -254,20 +282,28 @@ namespace OpenSim.Region.ClientStack.LindenUDP
 
             m_throttle = new TokenBucket(null, sceneThrottleBps);
             ThrottleRates = new ThrottleRates(configSource);
+
+            if (usePools)
+                EnablePools();
         }
 
         public void Start()
         {
-            if (m_scene == null)
-                throw new InvalidOperationException("[LLUDPSERVER]: Cannot LLUDPServer.Start() without an IScene reference");
+            StartInbound();
+            StartOutbound();
 
+            m_elapsedMSSinceLastStatReport = Environment.TickCount;
+        }
+
+        private void StartInbound()
+        {
             m_log.InfoFormat(
-                "[LLUDPSERVER]: Starting the LLUDP server in {0} mode",
-                m_asyncPacketHandling ? "asynchronous" : "synchronous");
+                "[LLUDPSERVER]: Starting inbound packet processing for the LLUDP server in {0} mode with UsePools = {1}",
+                m_asyncPacketHandling ? "asynchronous" : "synchronous", UsePools);
 
-            base.Start(m_recvBufferSize, m_asyncPacketHandling);
+            base.StartInbound(m_recvBufferSize, m_asyncPacketHandling);
 
-            // Start the packet processing threads
+            // This thread will process the packets received that are placed on the packetInbox
             Watchdog.StartThread(
                 IncomingPacketHandler,
                 string.Format("Incoming Packets ({0})", m_scene.RegionInfo.RegionName),
@@ -276,6 +312,13 @@ namespace OpenSim.Region.ClientStack.LindenUDP
                 true,
                 GetWatchdogIncomingAlarmData,
                 Watchdog.DEFAULT_WATCHDOG_TIMEOUT_MS);
+        }
+
+        private new void StartOutbound()
+        {
+            m_log.Info("[LLUDPSERVER]: Starting outbound packet processing for the LLUDP server");
+
+            base.StartOutbound();
 
             Watchdog.StartThread(
                 OutgoingPacketHandler,
@@ -285,8 +328,57 @@ namespace OpenSim.Region.ClientStack.LindenUDP
                 true,
                 GetWatchdogOutgoingAlarmData,
                 Watchdog.DEFAULT_WATCHDOG_TIMEOUT_MS);
+        }
 
-            m_elapsedMSSinceLastStatReport = Environment.TickCount;
+        public void Stop()
+        {
+            m_log.Info("[LLUDPSERVER]: Shutting down the LLUDP server for " + m_scene.RegionInfo.RegionName);
+            base.StopOutbound();
+            base.StopInbound();
+        }
+
+        protected override bool EnablePools()
+        {
+            if (!UsePools)
+            {
+                base.EnablePools();
+
+                m_incomingPacketPool = new Pool<IncomingPacket>(() => new IncomingPacket(), 500);
+
+                m_incomingPacketPoolStat
+                    = new Stat(
+                        "IncomingPacketPoolCount",
+                        "Objects within incoming packet pool",
+                        "The number of objects currently stored within the incoming packet pool",
+                        "",
+                        "clientstack",
+                        "packetpool",
+                        StatType.Pull,
+                        stat => stat.Value = m_incomingPacketPool.Count,
+                        StatVerbosity.Debug);
+
+                StatsManager.RegisterStat(m_incomingPacketPoolStat);
+
+                return true;
+            }
+
+            return false;
+        }
+
+        protected override bool DisablePools()
+        {
+            if (UsePools)
+            {
+                base.DisablePools();
+
+                StatsManager.DeregisterStat(m_incomingPacketPoolStat);
+
+                // We won't null out the pool to avoid a race condition with code that may be in the middle of using it.
+
+                return true;
+            }
+
+            return false;
         }
 
         /// <summary>
@@ -311,12 +403,6 @@ namespace OpenSim.Region.ClientStack.LindenUDP
                 m_currentOutgoingClient != null ? m_currentOutgoingClient.Name : "none");
         }
 
-        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)
@@ -333,6 +419,117 @@ namespace OpenSim.Region.ClientStack.LindenUDP
 
             m_scene = (Scene)scene;
             m_location = new Location(m_scene.RegionInfo.RegionHandle);
+
+            MainConsole.Instance.Commands.AddCommand(
+                "Debug",
+                false,
+                "debug lludp start",
+                "debug lludp start <in|out|all>",
+                "Control LLUDP packet processing.",
+                "No effect if packet processing has already started.\n"
+                    + "in  - start inbound processing.\n"
+                    + "out - start outbound processing.\n"
+                    + "all - start in and outbound processing.\n",
+                HandleStartCommand);
+
+            MainConsole.Instance.Commands.AddCommand(
+                "Debug",
+                false,
+                "debug lludp stop",
+                "debug lludp stop <in|out|all>",
+                "Stop LLUDP packet processing.",
+                "No effect if packet processing has already stopped.\n"
+                    + "in  - stop inbound processing.\n"
+                    + "out - stop outbound processing.\n"
+                    + "all - stop in and outbound processing.\n",
+                HandleStopCommand);
+
+            MainConsole.Instance.Commands.AddCommand(
+                "Debug",
+                false,
+                "debug lludp pool",
+                "debug lludp pool <on|off>",
+                "Turn object pooling within the lludp component on or off.",
+                HandlePoolCommand);
+
+            MainConsole.Instance.Commands.AddCommand(
+                "Debug",
+                false,
+                "debug lludp status",
+                "debug lludp status",
+                "Return status of LLUDP packet processing.",
+                HandleStatusCommand);
+        }
+
+        private void HandleStartCommand(string module, string[] args)
+        {
+            if (args.Length != 4)
+            {
+                MainConsole.Instance.Output("Usage: debug lludp start <in|out|all>");
+                return;
+            }
+
+            string subCommand = args[3];
+
+            if (subCommand == "in" || subCommand == "all")
+                StartInbound();
+
+            if (subCommand == "out" || subCommand == "all")
+                StartOutbound();
+        }
+
+        private void HandleStopCommand(string module, string[] args)
+        {
+            if (args.Length != 4)
+            {
+                MainConsole.Instance.Output("Usage: debug lludp stop <in|out|all>");
+                return;
+            }
+
+            string subCommand = args[3];
+
+            if (subCommand == "in" || subCommand == "all")
+                StopInbound();
+
+            if (subCommand == "out" || subCommand == "all")
+                StopOutbound();
+        }
+
+        private void HandlePoolCommand(string module, string[] args)
+        {
+            if (args.Length != 4)
+            {
+                MainConsole.Instance.Output("Usage: debug lludp pool <on|off>");
+                return;
+            }
+
+            string enabled = args[3];
+
+            if (enabled == "on")
+            {
+                if (EnablePools())
+                    MainConsole.Instance.OutputFormat("Packet pools enabled on {0}", m_scene.Name);
+            }
+            else if (enabled == "off")
+            {
+                if (DisablePools())
+                    MainConsole.Instance.OutputFormat("Packet pools disabled on {0}", m_scene.Name);
+            }
+            else
+            {
+                MainConsole.Instance.Output("Usage: debug lludp pool <on|off>");
+            }
+        }
+
+        private void HandleStatusCommand(string module, string[] args)
+        {
+            MainConsole.Instance.OutputFormat(
+                "IN  LLUDP packet processing for {0} is {1}", m_scene.Name, IsRunningInbound ? "enabled" : "disabled");
+
+            MainConsole.Instance.OutputFormat(
+                "OUT LLUDP packet processing for {0} is {1}", m_scene.Name, IsRunningOutbound ? "enabled" : "disabled");
+
+            MainConsole.Instance.OutputFormat("LLUDP pools in {0} are {1}", m_scene.Name, UsePools ? "on" : "off");
         }
 
         public bool HandlesRegion(Location x)
@@ -416,6 +613,8 @@ namespace OpenSim.Region.ClientStack.LindenUDP
                 byte[] data = packet.ToBytes();
                 SendPacketData(udpClient, data, packet.Type, category, method);
             }
+
+            PacketPool.Instance.ReturnPacket(packet);
         }
 
         /// <summary>
@@ -700,7 +899,7 @@ namespace OpenSim.Region.ClientStack.LindenUDP
             LLUDPClient udpClient = null;
             Packet packet = null;
             int packetEnd = buffer.DataLength - 1;
-            IPEndPoint address = (IPEndPoint)buffer.RemoteEndPoint;
+            IPEndPoint endPoint = (IPEndPoint)buffer.RemoteEndPoint;
 
             #region Decoding
 
@@ -710,7 +909,7 @@ namespace OpenSim.Region.ClientStack.LindenUDP
 //                    "[LLUDPSERVER]: Dropping undersized packet with {0} bytes received from {1} in {2}",
 //                    buffer.DataLength, buffer.RemoteEndPoint, m_scene.RegionInfo.RegionName);
 
-                return; // Drop undersizd packet
+                return; // Drop undersized packet
             }
 
             int headerLen = 7;
@@ -733,7 +932,13 @@ namespace OpenSim.Region.ClientStack.LindenUDP
 
             try
             {
-                packet = Packet.BuildPacket(buffer.Data, ref packetEnd,
+//                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);
+                // If OpenSimUDPBase.UsePool == true (which is currently separate from the PacketPool) then we
+                // assume that packet construction does not retain a reference to byte[] buffer.Data (instead, all
+                // bytes are copied out).
+                packet = PacketPool.Instance.GetPacket(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);
             }
@@ -748,11 +953,13 @@ namespace OpenSim.Region.ClientStack.LindenUDP
 
                 return; // Drop short packet
             }
-            catch(Exception e)
+            catch (Exception e)
             {
                 if (m_malformedCount < 100)
                     m_log.DebugFormat("[LLUDPSERVER]: Dropped malformed packet: " + e.ToString());
+
                 m_malformedCount++;
+
                 if ((m_malformedCount % 100000) == 0)
                     m_log.DebugFormat("[LLUDPSERVER]: Received {0} malformed packets so far, probable network attack.", m_malformedCount);
             }
@@ -772,7 +979,7 @@ namespace OpenSim.Region.ClientStack.LindenUDP
 
             // If there is already a client for this endpoint, don't process UseCircuitCode
             IClientAPI client = null;
-            if (!m_scene.TryGetClient(address, out client))
+            if (!m_scene.TryGetClient(endPoint, out client) || !(client is LLClientView))
             {
                 // UseCircuitCode handling
                 if (packet.Type == PacketType.UseCircuitCode)
@@ -780,13 +987,15 @@ namespace OpenSim.Region.ClientStack.LindenUDP
                     // And if there is a UseCircuitCode pending, also drop it
                     lock (m_pendingCache)
                     {
-                        if (m_pendingCache.Contains(address))
+                        if (m_pendingCache.Contains(endPoint))
                             return;
 
-                        m_pendingCache.AddOrUpdate(address, new Queue<UDPPacketBuffer>(), 60);
+                        m_pendingCache.AddOrUpdate(endPoint, new Queue<UDPPacketBuffer>(), 60);
                     }
 
-                    object[] array = new object[] { buffer, packet };
+                    // We need to copy the endpoint so that it doesn't get changed when another thread reuses the
+                    // buffer.
+                    object[] array = new object[] { new IPEndPoint(endPoint.Address, endPoint.Port), packet };
 
                     Util.FireAndForget(HandleUseCircuitCode, array);
 
@@ -798,7 +1007,7 @@ namespace OpenSim.Region.ClientStack.LindenUDP
             lock (m_pendingCache)
             {
                 Queue<UDPPacketBuffer> queue;
-                if (m_pendingCache.TryGetValue(address, out queue))
+                if (m_pendingCache.TryGetValue(endPoint, out queue))
                 {
                     //m_log.DebugFormat("[LLUDPSERVER]: Enqueued a {0} packet into the pending queue", packet.Type);
                     queue.Enqueue(buffer);
@@ -834,6 +1043,10 @@ namespace OpenSim.Region.ClientStack.LindenUDP
             // Handle appended ACKs
             if (packet.Header.AppendedAcks && packet.Header.AckList != null)
             {
+//                m_log.DebugFormat(
+//                    "[LLUDPSERVER]: Handling {0} appended acks from {1} in {2}",
+//                    packet.Header.AckList.Length, client.Name, m_scene.Name);
+
                 for (int i = 0; i < packet.Header.AckList.Length; i++)
                     udpClient.NeedAcks.Acknowledge(packet.Header.AckList[i], now, packet.Header.Resent);
             }
@@ -843,6 +1056,10 @@ namespace OpenSim.Region.ClientStack.LindenUDP
             {
                 PacketAckPacket ackPacket = (PacketAckPacket)packet;
 
+//                m_log.DebugFormat(
+//                    "[LLUDPSERVER]: Handling {0} packet acks for {1} in {2}",
+//                    ackPacket.Packets.Length, client.Name, m_scene.Name);
+
                 for (int i = 0; i < ackPacket.Packets.Length; i++)
                     udpClient.NeedAcks.Acknowledge(ackPacket.Packets[i].ID, now, packet.Header.Resent);
 
@@ -856,6 +1073,10 @@ namespace OpenSim.Region.ClientStack.LindenUDP
 
             if (packet.Header.Reliable)
             {
+//                m_log.DebugFormat(
+//                    "[LLUDPSERVER]: Adding ack request for {0} {1} from {2} in {3}",
+//                    packet.Type, packet.Header.Sequence, client.Name, m_scene.Name);
+
                 udpClient.PendingAcks.Enqueue(packet.Header.Sequence);
 
                 // This is a somewhat odd sequence of steps to pull the client.BytesSinceLastACK value out,
@@ -902,6 +1123,8 @@ namespace OpenSim.Region.ClientStack.LindenUDP
 
             if (packet.Type == PacketType.StartPingCheck)
             {
+//                m_log.DebugFormat("[LLUDPSERVER]: Handling ping from {0} in {1}", client.Name, m_scene.Name);
+
                 // We don't need to do anything else with ping checks
                 StartPingCheckPacket startPing = (StartPingCheckPacket)packet;
                 CompletePing(udpClient, startPing.PingID.PingID);
@@ -921,13 +1144,25 @@ namespace OpenSim.Region.ClientStack.LindenUDP
 
             #endregion Ping Check Handling
 
+            IncomingPacket incomingPacket;
+
             // Inbox insertion
-            if (packet.Type == PacketType.AgentUpdate ||
-                packet.Type == PacketType.ChatFromViewer)
-                packetInbox.EnqueueHigh(new IncomingPacket((LLClientView)client, packet));
+            if (UsePools)
+            {
+                incomingPacket = m_incomingPacketPool.GetObject();
+                incomingPacket.Client = (LLClientView)client;
+                incomingPacket.Packet = packet;
+            }
+            else
+            {
+                incomingPacket = new IncomingPacket((LLClientView)client, packet);
+            }
+
+            if (incomingPacket.Packet.Type == PacketType.AgentUpdate ||
+                incomingPacket.Packet.Type == PacketType.ChatFromViewer)
+                packetInbox.EnqueueHigh(incomingPacket);
             else
-                packetInbox.EnqueueLow(new IncomingPacket((LLClientView)client, packet));
-//            packetInbox.Enqueue(new IncomingPacket((LLClientView)client, packet));
+                packetInbox.EnqueueLow(incomingPacket);
         }
 
         #region BinaryStats
@@ -1013,21 +1248,19 @@ namespace OpenSim.Region.ClientStack.LindenUDP
 
         private void HandleUseCircuitCode(object o)
         {
-            IPEndPoint remoteEndPoint = null;
+            IPEndPoint endPoint = null;
             IClientAPI client = null;
 
             try
             {
     //            DateTime startTime = DateTime.Now;
                 object[] array = (object[])o;
-                UDPPacketBuffer buffer = (UDPPacketBuffer)array[0];
+                endPoint = (IPEndPoint)array[0];
                 UseCircuitCodePacket uccp = (UseCircuitCodePacket)array[1];
 
                 m_log.DebugFormat(
                     "[LLUDPSERVER]: Handling UseCircuitCode request for circuit {0} to {1} from IP {2}",
-                    uccp.CircuitCode.Code, m_scene.RegionInfo.RegionName, buffer.RemoteEndPoint);
-    
-                remoteEndPoint = (IPEndPoint)buffer.RemoteEndPoint;
+                    uccp.CircuitCode.Code, m_scene.RegionInfo.RegionName, endPoint);
     
                 AuthenticateResponse sessionInfo;
                 if (IsClientAuthorized(uccp, out sessionInfo))
@@ -1038,13 +1271,13 @@ namespace OpenSim.Region.ClientStack.LindenUDP
                             uccp.CircuitCode.Code,
                             uccp.CircuitCode.ID,
                             uccp.CircuitCode.SessionID,
-                            remoteEndPoint,
+                            endPoint,
                             sessionInfo);
             
                     // Send ack straight away to let the viewer know that the connection is active.
                     // The client will be null if it already exists (e.g. if on a region crossing the client sends a use
                     // circuit code to the existing child agent.  This is not particularly obvious.
-                    SendAckImmediate(remoteEndPoint, uccp.Header.Sequence);
+                    SendAckImmediate(endPoint, uccp.Header.Sequence);
             
                     // We only want to send initial data to new clients, not ones which are being converted from child to root.
                     if (client != null)
@@ -1058,12 +1291,12 @@ namespace OpenSim.Region.ClientStack.LindenUDP
 
                     lock (m_pendingCache)
                     {
-                        if (!m_pendingCache.TryGetValue(remoteEndPoint, out queue))
+                        if (!m_pendingCache.TryGetValue(endPoint, out queue))
                         {
                             m_log.DebugFormat("[LLUDPSERVER]: Client created but no pending queue present");
                             return;
                         }
-                        m_pendingCache.Remove(remoteEndPoint);
+                        m_pendingCache.Remove(endPoint);
                     }
 
                     m_log.DebugFormat("[LLUDPSERVER]: Client created, processing pending queue, {0} entries", queue.Count);
@@ -1081,9 +1314,9 @@ namespace OpenSim.Region.ClientStack.LindenUDP
                     // Don't create clients for unauthorized requesters.
                     m_log.WarnFormat(
                         "[LLUDPSERVER]: Ignoring connection request for {0} to {1} with unknown circuit code {2} from IP {3}",
-                        uccp.CircuitCode.ID, m_scene.RegionInfo.RegionName, uccp.CircuitCode.Code, remoteEndPoint);
+                        uccp.CircuitCode.ID, m_scene.RegionInfo.RegionName, uccp.CircuitCode.Code, endPoint);
                     lock (m_pendingCache)
-                        m_pendingCache.Remove(remoteEndPoint);
+                        m_pendingCache.Remove(endPoint);
                 }
     
                 //            m_log.DebugFormat(
@@ -1095,7 +1328,7 @@ namespace OpenSim.Region.ClientStack.LindenUDP
             {
                 m_log.ErrorFormat(
                     "[LLUDPSERVER]: UseCircuitCode handling from endpoint {0}, client {1} {2} failed.  Exception {3}{4}",
-                    remoteEndPoint != null ? remoteEndPoint.ToString() : "n/a",
+                    endPoint != null ? endPoint.ToString() : "n/a",
                     client != null ? client.Name : "unknown",
                     client != null ? client.AgentId.ToString() : "unknown",
                     e.Message,
@@ -1160,20 +1393,20 @@ namespace OpenSim.Region.ClientStack.LindenUDP
         {
             IClientAPI client = null;
 
-            // In priciple there shouldn't be more than one thread here, ever.
-            // But in case that happens, we need to synchronize this piece of code
-            // because it's too important
-            lock (this) 
+            // We currently synchronize this code across the whole scene to avoid issues such as
+            // http://opensimulator.org/mantis/view.php?id=5365  However, once locking per agent circuit can be done
+            // consistently, this lock could probably be removed.
+            lock (this)
             {
                 if (!m_scene.TryGetClient(agentID, out client))
                 {
                     LLUDPClient udpClient = new LLUDPClient(this, ThrottleRates, m_throttle, circuitCode, agentID, remoteEndPoint, m_defaultRTO, m_maxRTO);
-
+    
                     client = new LLClientView(m_scene, this, udpClient, sessionInfo, agentID, sessionID, circuitCode);
                     client.OnLogout += LogoutHandler;
-
+    
                     ((LLClientView)client).DisableFacelights = m_disableFacelights;
-
+    
                     client.Start();
                 }
             }
@@ -1212,7 +1445,7 @@ namespace OpenSim.Region.ClientStack.LindenUDP
             // on to en-US to avoid number parsing issues
             Culture.SetCurrentCulture();
 
-            while (base.IsRunning)
+            while (IsRunningInbound)
             {
                 m_scene.ThreadAlive(1);
                 try
@@ -1228,7 +1461,12 @@ namespace OpenSim.Region.ClientStack.LindenUDP
                     }
 
                     if (packetInbox.Dequeue(100, ref incomingPacket))
+                    {
                         ProcessInPacket(incomingPacket);//, incomingPacket); Util.FireAndForget(ProcessInPacket, incomingPacket);
+
+                        if (UsePools)
+                            m_incomingPacketPool.ReturnObject(incomingPacket);
+                    }
                 }
                 catch (Exception ex)
                 {
@@ -1255,7 +1493,7 @@ namespace OpenSim.Region.ClientStack.LindenUDP
             // Action generic every round
             Action<IClientAPI> clientPacketHandler = ClientOutgoingPacketHandler;
 
-            while (base.IsRunning)
+            while (base.IsRunningOutbound)
             {
                 m_scene.ThreadAlive(2);
                 try
@@ -1523,7 +1761,7 @@ namespace OpenSim.Region.ClientStack.LindenUDP
             if (!client.IsLoggingOut)
             {
                 client.IsLoggingOut = true;
-                client.Close(false);
+                client.Close(false, false);
             }
         }
     }
diff --git a/OpenSim/Region/ClientStack/Linden/UDP/OpenSimUDPBase.cs b/OpenSim/Region/ClientStack/Linden/UDP/OpenSimUDPBase.cs
index cfe7c9d..8bd3461 100644
--- a/OpenSim/Region/ClientStack/Linden/UDP/OpenSimUDPBase.cs
+++ b/OpenSim/Region/ClientStack/Linden/UDP/OpenSimUDPBase.cs
@@ -30,6 +30,8 @@ using System.Net;
 using System.Net.Sockets;
 using System.Threading;
 using log4net;
+using OpenSim.Framework;
+using OpenSim.Framework.Monitoring;
 
 namespace OpenMetaverse
 {
@@ -58,17 +60,31 @@ namespace OpenMetaverse
         /// <summary>Flag to process packets asynchronously or synchronously</summary>
         private bool m_asyncPacketHandling;
 
-        /// <summary>The all important shutdown flag</summary>
-        private volatile bool m_shutdownFlag = true;
+        /// <summary>
+        /// Pool to use for handling data.  May be null if UsePools = false;
+        /// </summary>
+        protected OpenSim.Framework.Pool<UDPPacketBuffer> m_pool;
+
+        /// <summary>
+        /// Are we to use object pool(s) to reduce memory churn when receiving data?
+        /// </summary>
+        public bool UsePools { get; protected set; }
+
+        /// <summary>Returns true if the server is currently listening for inbound packets, otherwise false</summary>
+        public bool IsRunningInbound { get; private set; }
 
-        /// <summary>Returns true if the server is currently listening, otherwise false</summary>
-        public bool IsRunning { get { return !m_shutdownFlag; } }
+        /// <summary>Returns true if the server is currently sending outbound packets, otherwise false</summary>
+        /// <remarks>If IsRunningOut = false, then any request to send a packet is simply dropped.</remarks>
+        public bool IsRunningOutbound { get; private set; }
+
+        private Stat m_poolCountStat;
 
         /// <summary>
         /// Default constructor
         /// </summary>
         /// <param name="bindAddress">Local IP address to bind the server to</param>
         /// <param name="port">Port to listening for incoming UDP packets on</param>
+        /// /// <param name="usePool">Are we to use an object pool to get objects for handing inbound data?</param>
         public OpenSimUDPBase(IPAddress bindAddress, int port)
         {
             m_localBindAddress = bindAddress;
@@ -76,7 +92,7 @@ namespace OpenMetaverse
         }
 
         /// <summary>
-        /// Start the UDP server
+        /// Start inbound UDP packet handling.
         /// </summary>
         /// <param name="recvBufferSize">The size of the receive buffer for 
         /// the UDP socket. This value is passed up to the operating system 
@@ -91,11 +107,11 @@ namespace OpenMetaverse
         /// manner (not throwing an exception when the remote side resets the
         /// connection). This call is ignored on Mono where the flag is not
         /// necessary</remarks>
-        public void Start(int recvBufferSize, bool asyncPacketHandling)
+        public void StartInbound(int recvBufferSize, bool asyncPacketHandling)
         {
             m_asyncPacketHandling = asyncPacketHandling;
 
-            if (m_shutdownFlag)
+            if (!IsRunningInbound)
             {
                 const int SIO_UDP_CONNRESET = -1744830452;
 
@@ -123,8 +139,7 @@ namespace OpenMetaverse
 
                 m_udpSocket.Bind(ipep);
 
-                // we're not shutting down, we're starting up
-                m_shutdownFlag = false;
+                IsRunningInbound = true;
 
                 // kick off an async receive.  The Start() method will return, the
                 // actual receives will occur asynchronously and will be caught in
@@ -134,28 +149,84 @@ namespace OpenMetaverse
         }
 
         /// <summary>
-        /// Stops the UDP server
+        /// Start outbound UDP packet handling.
         /// </summary>
-        public void Stop()
+        public void StartOutbound()
+        {
+            IsRunningOutbound = true;
+        }
+
+        public void StopInbound()
         {
-            if (!m_shutdownFlag)
+            if (IsRunningInbound)
             {
                 // wait indefinitely for a writer lock.  Once this is called, the .NET runtime
                 // will deny any more reader locks, in effect blocking all other send/receive
-                // threads.  Once we have the lock, we set shutdownFlag to inform the other
+                // threads.  Once we have the lock, we set IsRunningInbound = false to inform the other
                 // threads that the socket is closed.
-                m_shutdownFlag = true;
+                IsRunningInbound = false;
                 m_udpSocket.Close();
             }
         }
 
+        public void StopOutbound()
+        {
+            IsRunningOutbound = false;
+        }
+
+        protected virtual bool EnablePools()
+        {
+            if (!UsePools)
+            {
+                m_pool = new Pool<UDPPacketBuffer>(() => new UDPPacketBuffer(), 500);
+
+                m_poolCountStat
+                    = new Stat(
+                        "UDPPacketBufferPoolCount",
+                        "Objects within the UDPPacketBuffer pool",
+                        "The number of objects currently stored within the UDPPacketBuffer pool",
+                        "",
+                        "clientstack",
+                        "packetpool",
+                        StatType.Pull,
+                        stat => stat.Value = m_pool.Count,
+                        StatVerbosity.Debug);
+
+                StatsManager.RegisterStat(m_poolCountStat);
+
+                UsePools = true;
+
+                return true;
+            }
+
+            return false;
+        }
+
+        protected virtual bool DisablePools()
+        {
+            if (UsePools)
+            {
+                UsePools = false;
+                StatsManager.DeregisterStat(m_poolCountStat);
+
+                // We won't null out the pool to avoid a race condition with code that may be in the middle of using it.
+
+                return true;
+            }
+
+            return false;
+        }
+
         private void AsyncBeginReceive()
         {
-            // allocate a packet buffer
-            //WrappedObject<UDPPacketBuffer> wrappedBuffer = Pool.CheckOut();
-            UDPPacketBuffer buf = new UDPPacketBuffer();
+            UDPPacketBuffer buf;
+
+            if (UsePools)
+                buf = m_pool.GetObject();
+            else
+                buf = new UDPPacketBuffer();
 
-            if (!m_shutdownFlag)
+            if (IsRunningInbound)
             {
                 try
                 {
@@ -208,7 +279,7 @@ namespace OpenMetaverse
         {
             // Asynchronous receive operations will complete here through the call
             // to AsyncBeginReceive
-            if (!m_shutdownFlag)
+            if (IsRunningInbound)
             {
                 // Asynchronous mode will start another receive before the
                 // callback for this packet is even fired. Very parallel :-)
@@ -217,8 +288,6 @@ namespace OpenMetaverse
 
                 // get the buffer that was created in AsyncBeginReceive
                 // this is the received data
-                //WrappedObject<UDPPacketBuffer> wrappedBuffer = (WrappedObject<UDPPacketBuffer>)iar.AsyncState;
-                //UDPPacketBuffer buffer = wrappedBuffer.Instance;
                 UDPPacketBuffer buffer = (UDPPacketBuffer)iar.AsyncState;
 
                 try
@@ -235,7 +304,8 @@ namespace OpenMetaverse
                 catch (ObjectDisposedException) { }
                 finally
                 {
-                    //wrappedBuffer.Dispose();
+                    if (UsePools)
+                        m_pool.ReturnObject(buffer);
 
                     // Synchronous mode waits until the packet callback completes
                     // before starting the receive to fetch another packet
@@ -248,7 +318,7 @@ namespace OpenMetaverse
 
         public void AsyncBeginSend(UDPPacketBuffer buf)
         {
-            if (!m_shutdownFlag)
+            if (IsRunningOutbound)
             {
                 try
                 {
diff --git a/OpenSim/Region/ClientStack/Linden/UDP/PacketPool.cs b/OpenSim/Region/ClientStack/Linden/UDP/PacketPool.cs
new file mode 100644
index 0000000..9f22fb4
--- /dev/null
+++ b/OpenSim/Region/ClientStack/Linden/UDP/PacketPool.cs
@@ -0,0 +1,316 @@
+/*
+ * 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.Reflection;
+using OpenMetaverse;
+using OpenMetaverse.Packets;
+using log4net;
+using OpenSim.Framework.Monitoring;
+
+namespace OpenSim.Region.ClientStack.LindenUDP
+{
+    public sealed class PacketPool
+    {
+        private static readonly ILog m_log = LogManager.GetLogger(MethodBase.GetCurrentMethod().DeclaringType);
+
+        private static readonly PacketPool instance = new PacketPool();
+
+        private bool packetPoolEnabled = true;
+        private bool dataBlockPoolEnabled = true;
+
+        private PercentageStat m_packetsReusedStat = new PercentageStat(
+            "PacketsReused",
+            "Packets reused",
+            "Number of packets reused out of all requests to the packet pool",
+            "clientstack",
+            "packetpool",
+            StatType.Push,
+            null,
+            StatVerbosity.Debug);
+
+        private PercentageStat m_blocksReusedStat = new PercentageStat(
+            "PacketDataBlocksReused",
+            "Packet data blocks reused",
+            "Number of data blocks reused out of all requests to the packet pool",
+            "clientstack",
+            "packetpool",
+            StatType.Push,
+            null,
+            StatVerbosity.Debug);
+
+        /// <summary>
+        /// Pool of packets available for reuse.
+        /// </summary>
+        private readonly Dictionary<PacketType, Stack<Packet>> pool = new Dictionary<PacketType, Stack<Packet>>();
+
+        private static Dictionary<Type, Stack<Object>> DataBlocks = new Dictionary<Type, Stack<Object>>();
+
+        public static PacketPool Instance
+        {
+            get { return instance; }
+        }
+
+        public bool RecyclePackets
+        {
+            set { packetPoolEnabled = value; }
+            get { return packetPoolEnabled; }
+        }
+
+        public bool RecycleDataBlocks
+        {
+            set { dataBlockPoolEnabled = value; }
+            get { return dataBlockPoolEnabled; }
+        }
+
+        private PacketPool()
+        {
+            StatsManager.RegisterStat(m_packetsReusedStat);
+            StatsManager.RegisterStat(m_blocksReusedStat);
+
+            StatsManager.RegisterStat(
+                new Stat(
+                    "PacketsPoolCount",
+                    "Objects within the packet pool",
+                    "The number of objects currently stored within the packet pool",
+                    "",
+                    "clientstack",
+                    "packetpool",
+                    StatType.Pull,
+                    stat => { lock (pool) { stat.Value = pool.Count; } },
+                    StatVerbosity.Debug));
+
+            StatsManager.RegisterStat(
+                new Stat(
+                    "PacketDataBlocksPoolCount",
+                    "Objects within the packet data block pool",
+                    "The number of objects currently stored within the packet data block pool",
+                    "",
+                    "clientstack",
+                    "packetpool",
+                    StatType.Pull,
+                    stat => { lock (DataBlocks) { stat.Value = DataBlocks.Count; } },
+                    StatVerbosity.Debug));
+        }
+
+        /// <summary>
+        /// Gets a packet of the given type.
+        /// </summary>
+        /// <param name='type'></param>
+        /// <returns>Guaranteed to always return a packet, whether from the pool or newly constructed.</returns>
+        public Packet GetPacket(PacketType type)
+        {
+            m_packetsReusedStat.Consequent++;
+
+            Packet packet;
+
+            if (!packetPoolEnabled)
+                return Packet.BuildPacket(type);
+
+            lock (pool)
+            {
+                if (!pool.ContainsKey(type) || pool[type] == null || (pool[type]).Count == 0)
+                {
+//                    m_log.DebugFormat("[PACKETPOOL]: Building {0} packet", type);
+
+                    // Creating a new packet if we cannot reuse an old package
+                    packet = Packet.BuildPacket(type);
+                }
+                else
+                {
+//                    m_log.DebugFormat("[PACKETPOOL]: Pulling {0} packet", type);
+
+                    // Recycle old packages
+                    m_packetsReusedStat.Antecedent++;
+
+                    packet = pool[type].Pop();
+                }
+            }
+
+            return packet;
+        }
+
+        // private byte[] decoded_header = new byte[10];
+        private static PacketType GetType(byte[] bytes)
+        {
+            byte[] decoded_header = new byte[10 + 8];
+            ushort id;
+            PacketFrequency freq;
+
+            if ((bytes[0] & Helpers.MSG_ZEROCODED) != 0)
+            {
+                Helpers.ZeroDecode(bytes, 16, decoded_header);
+            }
+            else
+            {
+                Buffer.BlockCopy(bytes, 0, decoded_header, 0, 10);
+            }
+
+            if (decoded_header[6] == 0xFF)
+            {
+                if (decoded_header[7] == 0xFF)
+                {
+                    id = (ushort) ((decoded_header[8] << 8) + decoded_header[9]);
+                    freq = PacketFrequency.Low;
+                }
+                else
+                {
+                    id = decoded_header[7];
+                    freq = PacketFrequency.Medium;
+                }
+            }
+            else
+            {
+                id = decoded_header[6];
+                freq = PacketFrequency.High;
+            }
+
+            return Packet.GetType(id, freq);
+        }
+
+        public Packet GetPacket(byte[] bytes, ref int packetEnd, byte[] zeroBuffer)
+        {
+            PacketType type = GetType(bytes);
+
+//            Array.Clear(zeroBuffer, 0, zeroBuffer.Length);
+
+            int i = 0;
+            Packet packet = GetPacket(type);
+            if (packet == null)
+                m_log.WarnFormat("[PACKETPOOL]: Failed to get packet of type {0}", type);
+            else
+                packet.FromBytes(bytes, ref i, ref packetEnd, zeroBuffer);
+
+            return packet;
+        }
+
+        /// <summary>
+        /// Return a packet to the packet pool
+        /// </summary>
+        /// <param name="packet"></param>
+        public void ReturnPacket(Packet packet)
+        {
+            if (dataBlockPoolEnabled)
+            {
+                switch (packet.Type)
+                {
+                    case PacketType.ObjectUpdate:
+                        ObjectUpdatePacket oup = (ObjectUpdatePacket)packet;
+
+                        foreach (ObjectUpdatePacket.ObjectDataBlock oupod in oup.ObjectData)
+                            ReturnDataBlock<ObjectUpdatePacket.ObjectDataBlock>(oupod);
+
+                        oup.ObjectData = null;
+                        break;
+
+                    case PacketType.ImprovedTerseObjectUpdate:
+                        ImprovedTerseObjectUpdatePacket itoup = (ImprovedTerseObjectUpdatePacket)packet;
+
+                        foreach (ImprovedTerseObjectUpdatePacket.ObjectDataBlock itoupod in itoup.ObjectData)
+                            ReturnDataBlock<ImprovedTerseObjectUpdatePacket.ObjectDataBlock>(itoupod);
+
+                        itoup.ObjectData = null;
+                        break;
+                }
+            }
+
+            if (packetPoolEnabled)
+            {
+                switch (packet.Type)
+                {
+                    // List pooling packets here
+                    case PacketType.AgentUpdate:
+                    case PacketType.PacketAck:
+                    case PacketType.ObjectUpdate:
+                    case PacketType.ImprovedTerseObjectUpdate:
+                        lock (pool)
+                        {
+                            PacketType type = packet.Type;
+
+                            if (!pool.ContainsKey(type))
+                            {
+                                pool[type] = new Stack<Packet>();
+                            }
+
+                            if ((pool[type]).Count < 50)
+                            {
+//                                m_log.DebugFormat("[PACKETPOOL]: Pushing {0} packet", type);
+
+                                pool[type].Push(packet);
+                            }
+                        }
+                        break;
+                    
+                    // Other packets wont pool
+                    default:
+                        return;
+                }
+            }
+        }
+
+        public T GetDataBlock<T>() where T: new()
+        {
+            lock (DataBlocks)
+            {
+                m_blocksReusedStat.Consequent++;
+
+                Stack<Object> s;
+
+                if (DataBlocks.TryGetValue(typeof(T), out s))
+                {
+                    if (s.Count > 0)
+                    {
+                        m_blocksReusedStat.Antecedent++;
+                        return (T)s.Pop();
+                    }
+                }
+                else
+                {
+                    DataBlocks[typeof(T)] = new Stack<Object>();
+                }
+                
+                return new T();
+            }
+        }
+
+        public void ReturnDataBlock<T>(T block) where T: new()
+        {
+            if (block == null)
+                return;
+
+            lock (DataBlocks)
+            {
+                if (!DataBlocks.ContainsKey(typeof(T)))
+                    DataBlocks[typeof(T)] = new Stack<Object>();
+
+                if (DataBlocks[typeof(T)].Count < 50)
+                    DataBlocks[typeof(T)].Push(block);
+            }
+        }
+    }
+}
\ No newline at end of file
diff --git a/OpenSim/Region/ClientStack/Linden/UDP/Tests/BasicCircuitTests.cs b/OpenSim/Region/ClientStack/Linden/UDP/Tests/BasicCircuitTests.cs
index 109a8e1..556df30 100644
--- a/OpenSim/Region/ClientStack/Linden/UDP/Tests/BasicCircuitTests.cs
+++ b/OpenSim/Region/ClientStack/Linden/UDP/Tests/BasicCircuitTests.cs
@@ -43,7 +43,7 @@ namespace OpenSim.Region.ClientStack.LindenUDP.Tests
     /// This will contain basic tests for the LindenUDP client stack
     /// </summary>
     [TestFixture]
-    public class BasicCircuitTests
+    public class BasicCircuitTests : OpenSimTestCase
     {
         private Scene m_scene;
         private TestLLUDPServer m_udpServer;
@@ -65,8 +65,9 @@ namespace OpenSim.Region.ClientStack.LindenUDP.Tests
         }
 
         [SetUp]
-        public void SetUp()
+        public override void SetUp()
         {
+            base.SetUp();
             m_scene = new SceneHelpers().SetupScene();
         }
         
@@ -143,7 +144,7 @@ namespace OpenSim.Region.ClientStack.LindenUDP.Tests
         public void TestAddClient()
         {
             TestHelpers.InMethod();
-//            XmlConfigurator.Configure();
+//            TestHelpers.EnableLogging();
 
             AddUdpServer();