First stab at cleaning up Caps. Compiles. Untested.

OpenSim/Region/ClientStack/Linden/UDP/IncomingPacket.cs

@@ -0,0 +1,57 @@
+/*
+ * 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 OpenSim.Framework;
+using OpenMetaverse;
+using OpenMetaverse.Packets;
+
+namespace OpenSim.Region.ClientStack.LindenUDP
+{
+    /// <summary>
+    /// Holds a reference to a <seealso cref="LLUDPClient"/> and a <seealso cref="Packet"/>
+    /// for incoming packets
+    /// </summary>
+    public sealed class IncomingPacket
+    {
+        /// <summary>Client this packet came from</summary>
+        public LLUDPClient Client;
+        /// <summary>Packet data that has been received</summary>
+        public Packet Packet;
+
+        /// <summary>
+        /// Default constructor
+        /// </summary>
+        /// <param name="client">Reference to the client this packet came from</param>
+        /// <param name="packet">Packet data</param>
+        public IncomingPacket(LLUDPClient client, Packet packet)
+        {
+            Client = client;
+            Packet = packet;
+        }
+    }
+}

OpenSim/Region/ClientStack/Linden/UDP/IncomingPacketHistoryCollection.cs

@@ -0,0 +1,73 @@
+/*
+ * 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;
+
+namespace OpenSim.Region.ClientStack.LindenUDP
+{
+    /// <summary>
+    /// A circular buffer and hashset for tracking incoming packet sequence
+    /// numbers
+    /// </summary>
+    public sealed class IncomingPacketHistoryCollection
+    {
+        private readonly uint[] m_items;
+        private HashSet<uint> m_hashSet;
+        private int m_first;
+        private int m_next;
+        private int m_capacity;
+
+        public IncomingPacketHistoryCollection(int capacity)
+        {
+            this.m_capacity = capacity;
+            m_items = new uint[capacity];
+            m_hashSet = new HashSet<uint>();
+        }
+
+        public bool TryEnqueue(uint ack)
+        {
+            lock (m_hashSet)
+            {
+                if (m_hashSet.Add(ack))
+                {
+                    m_items[m_next] = ack;
+                    m_next = (m_next + 1) % m_capacity;
+                    if (m_next == m_first)
+                    {
+                        m_hashSet.Remove(m_items[m_first]);
+                        m_first = (m_first + 1) % m_capacity;
+                    }
+
+                    return true;
+                }
+            }
+
+            return false;
+        }
+    }
+}

OpenSim/Region/ClientStack/Linden/UDP/J2KImage.cs

@@ -0,0 +1,398 @@
+/*
+ * 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 OpenMetaverse;
+using OpenMetaverse.Imaging;
+using OpenSim.Framework;
+using OpenSim.Region.Framework.Interfaces;
+using OpenSim.Services.Interfaces;
+using log4net;
+using System.Reflection;
+
+namespace OpenSim.Region.ClientStack.LindenUDP
+{
+    /// <summary>
+    /// Stores information about a current texture download and a reference to the texture asset
+    /// </summary>
+    public class J2KImage
+    {
+        private const int IMAGE_PACKET_SIZE = 1000;
+        private const int FIRST_PACKET_SIZE = 600;
+
+        private static readonly ILog m_log = LogManager.GetLogger(MethodBase.GetCurrentMethod().DeclaringType);
+
+        public uint LastSequence;
+        public float Priority;
+        public uint StartPacket;
+        public sbyte DiscardLevel;
+        public UUID TextureID;
+        public IJ2KDecoder J2KDecoder;
+        public IAssetService AssetService;
+        public UUID AgentID;
+        public IInventoryAccessModule InventoryAccessModule;
+        public OpenJPEG.J2KLayerInfo[] Layers;
+        public bool IsDecoded;
+        public bool HasAsset;
+        public C5.IPriorityQueueHandle<J2KImage> PriorityQueueHandle;
+
+        private uint m_currentPacket;
+        private bool m_decodeRequested;
+        private bool m_assetRequested;
+        private bool m_sentInfo;
+        private uint m_stopPacket;
+        private byte[] m_asset;
+        private LLImageManager m_imageManager;
+
+        public J2KImage(LLImageManager imageManager)
+        {
+            m_imageManager = imageManager;
+        }
+
+        /// <summary>
+        /// Sends packets for this texture to a client until packetsToSend is 
+        /// hit or the transfer completes
+        /// </summary>
+        /// <param name="client">Reference to the client that the packets are destined for</param>
+        /// <param name="packetsToSend">Maximum number of packets to send during this call</param>
+        /// <param name="packetsSent">Number of packets sent during this call</param>
+        /// <returns>True if the transfer completes at the current discard level, otherwise false</returns>
+        public bool SendPackets(LLClientView client, int packetsToSend, out int packetsSent)
+        {
+            packetsSent = 0;
+
+            if (m_currentPacket <= m_stopPacket)
+            {
+                bool sendMore = true;
+
+                if (!m_sentInfo || (m_currentPacket == 0))
+                {
+                    sendMore = !SendFirstPacket(client);
+
+                    m_sentInfo = true;
+                    ++m_currentPacket;
+                    ++packetsSent;
+                }
+                if (m_currentPacket < 2)
+                {
+                    m_currentPacket = 2;
+                }
+                
+                while (sendMore && packetsSent < packetsToSend && m_currentPacket <= m_stopPacket)
+                {
+                    sendMore = SendPacket(client);
+                    ++m_currentPacket;
+                    ++packetsSent;
+                }
+            }
+
+            return (m_currentPacket > m_stopPacket);
+        }
+
+        public void RunUpdate()
+        {
+            //This is where we decide what we need to update
+            //and assign the real discardLevel and packetNumber
+            //assuming of course that the connected client might be bonkers
+
+            if (!HasAsset)
+            {
+                if (!m_assetRequested)
+                {
+                    m_assetRequested = true;
+                    AssetService.Get(TextureID.ToString(), this, AssetReceived);
+                }
+            }
+            else
+            {
+                if (!IsDecoded)
+                {
+                    //We need to decode the requested image first
+                    if (!m_decodeRequested)
+                    {
+                        //Request decode
+                        m_decodeRequested = true;
+                        // Do we have a jpeg decoder?
+                        if (J2KDecoder != null)
+                        {
+                            if (m_asset == null)
+                            {
+                                J2KDecodedCallback(TextureID, new OpenJPEG.J2KLayerInfo[0]);
+                            }
+                            else
+                            {
+                                // Send it off to the jpeg decoder
+                                J2KDecoder.BeginDecode(TextureID, m_asset, J2KDecodedCallback);
+                            }
+
+                        }
+                        else
+                        {
+                            J2KDecodedCallback(TextureID, new OpenJPEG.J2KLayerInfo[0]);
+                        }
+                    }
+                }
+                else
+                {
+                    // Check for missing image asset data
+                    if (m_asset == null)
+                    {
+                        m_log.Warn("[J2KIMAGE]: RunUpdate() called with missing asset data (no missing image texture?). Canceling texture transfer");
+                        m_currentPacket = m_stopPacket;
+                        return;
+                    }
+                    
+                    if (DiscardLevel >= 0 || m_stopPacket == 0)
+                    {
+                        // This shouldn't happen, but if it does, we really can't proceed
+                        if (Layers == null)
+                        {
+                            m_log.Warn("[J2KIMAGE]: RunUpdate() called with missing Layers. Canceling texture transfer");
+                            m_currentPacket = m_stopPacket;
+                            return;
+                        }
+
+                        int maxDiscardLevel = Math.Max(0, Layers.Length - 1);
+
+                        // Treat initial texture downloads with a DiscardLevel of -1 a request for the highest DiscardLevel
+                        if (DiscardLevel < 0 && m_stopPacket == 0)
+                            DiscardLevel = (sbyte)maxDiscardLevel;
+
+                        // Clamp at the highest discard level
+                        DiscardLevel = (sbyte)Math.Min(DiscardLevel, maxDiscardLevel);
+
+                        //Calculate the m_stopPacket
+                        if (Layers.Length > 0)
+                        {
+                            m_stopPacket = (uint)GetPacketForBytePosition(Layers[(Layers.Length - 1) - DiscardLevel].End);
+                            //I don't know why, but the viewer seems to expect the final packet if the file
+                            //is just one packet bigger.
+                            if (TexturePacketCount() == m_stopPacket + 1)
+                            {
+                                m_stopPacket = TexturePacketCount();
+                            }
+                        }
+                        else
+                        {
+                            m_stopPacket = TexturePacketCount();
+                        }
+
+                        m_currentPacket = StartPacket;
+                    }
+                }
+            }
+        }
+
+        private bool SendFirstPacket(LLClientView client)
+        {
+            if (client == null)
+                return false;
+
+            if (m_asset == null)
+            {
+                m_log.Warn("[J2KIMAGE]: Sending ImageNotInDatabase for texture " + TextureID);
+                client.SendImageNotFound(TextureID);
+                return true;
+            }
+            else if (m_asset.Length <= FIRST_PACKET_SIZE)
+            {
+                // We have less then one packet's worth of data
+                client.SendImageFirstPart(1, TextureID, (uint)m_asset.Length, m_asset, 2);
+                m_stopPacket = 0;
+                return true;
+            }
+            else
+            {
+                // This is going to be a multi-packet texture download
+                byte[] firstImageData = new byte[FIRST_PACKET_SIZE];
+
+                try { Buffer.BlockCopy(m_asset, 0, firstImageData, 0, FIRST_PACKET_SIZE); }
+                catch (Exception)
+                {
+                    m_log.ErrorFormat("[J2KIMAGE]: Texture block copy for the first packet failed. textureid={0}, assetlength={1}", TextureID, m_asset.Length);
+                    return true;
+                }
+
+                client.SendImageFirstPart(TexturePacketCount(), TextureID, (uint)m_asset.Length, firstImageData, (byte)ImageCodec.J2C);
+            }
+            return false;
+        }
+
+        private bool SendPacket(LLClientView client)
+        {
+            if (client == null)
+                return false;
+
+            bool complete = false;
+            int imagePacketSize = ((int)m_currentPacket == (TexturePacketCount())) ? LastPacketSize() : IMAGE_PACKET_SIZE;
+
+            try
+            {
+                if ((CurrentBytePosition() + IMAGE_PACKET_SIZE) > m_asset.Length)
+                {
+                    imagePacketSize = LastPacketSize();
+                    complete = true;
+                    if ((CurrentBytePosition() + imagePacketSize) > m_asset.Length)
+                    {
+                        imagePacketSize = m_asset.Length - CurrentBytePosition();
+                        complete = true;
+                    }
+                }
+
+                // It's concievable that the client might request packet one
+                // from a one packet image, which is really packet 0,
+                // which would leave us with a negative imagePacketSize..
+                if (imagePacketSize > 0)
+                {
+                    byte[] imageData = new byte[imagePacketSize];
+                    int currentPosition = CurrentBytePosition();
+
+                    try { Buffer.BlockCopy(m_asset, currentPosition, imageData, 0, imagePacketSize); }
+                    catch (Exception e)
+                    {
+                        m_log.ErrorFormat("[J2KIMAGE]: Texture block copy for the first packet failed. textureid={0}, assetlength={1}, currentposition={2}, imagepacketsize={3}, exception={4}",
+                            TextureID, m_asset.Length, currentPosition, imagePacketSize, e.Message);
+                        return false;
+                    }
+
+                    //Send the packet
+                    client.SendImageNextPart((ushort)(m_currentPacket - 1), TextureID, imageData);
+                }
+
+                return !complete;
+            }
+            catch (Exception)
+            {
+                return false;
+            }
+        }
+
+        private ushort TexturePacketCount()
+        {
+            if (!IsDecoded)
+                return 0;
+
+            if (m_asset == null)
+                return 0;
+
+            if (m_asset.Length <= FIRST_PACKET_SIZE)
+                return 1;
+
+            return (ushort)(((m_asset.Length - FIRST_PACKET_SIZE + IMAGE_PACKET_SIZE - 1) / IMAGE_PACKET_SIZE) + 1);
+        }
+
+        private int GetPacketForBytePosition(int bytePosition)
+        {
+            return ((bytePosition - FIRST_PACKET_SIZE + IMAGE_PACKET_SIZE - 1) / IMAGE_PACKET_SIZE) + 1;
+        }
+
+        private int LastPacketSize()
+        {
+            if (m_currentPacket == 1)
+                return m_asset.Length;
+            int lastsize = (m_asset.Length - FIRST_PACKET_SIZE) % IMAGE_PACKET_SIZE;
+            //If the last packet size is zero, it's really cImagePacketSize, it sits on the boundary
+            if (lastsize == 0)
+            {
+                lastsize = IMAGE_PACKET_SIZE;
+            }
+            return lastsize;
+        }
+
+        private int CurrentBytePosition()
+        {
+            if (m_currentPacket == 0)
+                return 0;
+            if (m_currentPacket == 1)
+                return FIRST_PACKET_SIZE;
+
+            int result = FIRST_PACKET_SIZE + ((int)m_currentPacket - 2) * IMAGE_PACKET_SIZE;
+            if (result < 0)
+            {
+                result = FIRST_PACKET_SIZE;
+            }
+            return result;
+        }
+
+        private void J2KDecodedCallback(UUID AssetId, OpenJPEG.J2KLayerInfo[] layers)
+        {
+            Layers = layers;
+            IsDecoded = true;
+            RunUpdate();
+        }
+
+        private void AssetDataCallback(UUID AssetID, AssetBase asset)
+        {
+            HasAsset = true;
+
+            if (asset == null || asset.Data == null)
+            {
+                if (m_imageManager.MissingImage != null)
+                {
+                    m_asset = m_imageManager.MissingImage.Data;
+                }
+                else
+                {
+                    m_asset = null;
+                    IsDecoded = true;
+                }
+            }
+            else
+            {
+                m_asset = asset.Data;
+            }
+
+            RunUpdate();
+        }
+
+        private void AssetReceived(string id, Object sender, AssetBase asset)
+        {
+            UUID assetID = UUID.Zero;
+            if (asset != null)
+                assetID = asset.FullID;
+            else if ((InventoryAccessModule != null) && (sender != InventoryAccessModule))
+            {
+                // Unfortunately we need this here, there's no other way.
+                // This is due to the fact that textures opened directly from the agent's inventory
+                // don't have any distinguishing feature. As such, in order to serve those when the
+                // foreign user is visiting, we need to try again after the first fail to the local
+                // asset service.
+                string assetServerURL = string.Empty;
+                if (InventoryAccessModule.IsForeignUser(AgentID, out assetServerURL))
+                {
+                    m_log.DebugFormat("[J2KIMAGE]: texture {0} not found in local asset storage. Trying user's storage.", id);
+                    AssetService.Get(assetServerURL + "/" + id, InventoryAccessModule, AssetReceived);
+                    return;
+                }
+            }
+
+            AssetDataCallback(assetID, asset);
+
+        }
+    }
+}

OpenSim/Region/ClientStack/Linden/UDP/LLImageManager.cs

@@ -0,0 +1,257 @@
+/*
+ * 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.Threading;
+using System.Collections;
+using System.Collections.Generic;
+using System.Reflection;
+using OpenMetaverse;
+using OpenMetaverse.Imaging;
+using OpenSim.Framework;
+using OpenSim.Region.Framework.Interfaces;
+using OpenSim.Services.Interfaces;
+using log4net;
+
+namespace OpenSim.Region.ClientStack.LindenUDP
+{
+    public class LLImageManager
+    {
+        private sealed class J2KImageComparer : IComparer<J2KImage>
+        {
+            public int Compare(J2KImage x, J2KImage y)
+            {
+                return x.Priority.CompareTo(y.Priority);
+            }
+        }
+
+        private static readonly ILog m_log = LogManager.GetLogger(MethodBase.GetCurrentMethod().DeclaringType);
+        private bool m_shuttingdown;
+        private AssetBase m_missingImage;
+        private LLClientView m_client; //Client we're assigned to
+        private IAssetService m_assetCache; //Asset Cache
+        private IJ2KDecoder m_j2kDecodeModule; //Our J2K module
+        private C5.IntervalHeap<J2KImage> m_priorityQueue = new C5.IntervalHeap<J2KImage>(10, new J2KImageComparer());
+        private object m_syncRoot = new object();
+
+        public LLClientView Client { get { return m_client; } }
+        public AssetBase MissingImage { get { return m_missingImage; } }
+
+        public LLImageManager(LLClientView client, IAssetService pAssetCache, IJ2KDecoder pJ2kDecodeModule)
+        {
+            m_client = client;
+            m_assetCache = pAssetCache;
+
+            if (pAssetCache != null)
+                m_missingImage = pAssetCache.Get("5748decc-f629-461c-9a36-a35a221fe21f");
+            
+            if (m_missingImage == null)
+                m_log.Error("[ClientView] - Couldn't set missing image asset, falling back to missing image packet. This is known to crash the client");
+
+            m_j2kDecodeModule = pJ2kDecodeModule;
+        }
+
+        /// <summary>
+        /// Handles an incoming texture request or update to an existing texture request
+        /// </summary>
+        /// <param name="newRequest"></param>
+        public void EnqueueReq(TextureRequestArgs newRequest)
+        {
+            //Make sure we're not shutting down..
+            if (!m_shuttingdown)
+            {
+                J2KImage imgrequest;
+
+                // Do a linear search for this texture download
+                lock (m_syncRoot)
+                    m_priorityQueue.Find(delegate(J2KImage img) { return img.TextureID == newRequest.RequestedAssetID; }, out imgrequest);
+
+                if (imgrequest != null)
+                {
+                    if (newRequest.DiscardLevel == -1 && newRequest.Priority == 0f)
+                    {
+                        //m_log.Debug("[TEX]: (CAN) ID=" + newRequest.RequestedAssetID);
+
+                        try 
+                        {
+                            lock (m_syncRoot)
+                                m_priorityQueue.Delete(imgrequest.PriorityQueueHandle); 
+                        }
+                        catch (Exception) { }
+                    }
+                    else
+                    {
+                        //m_log.DebugFormat("[TEX]: (UPD) ID={0}: D={1}, S={2}, P={3}",
+                        //    newRequest.RequestedAssetID, newRequest.DiscardLevel, newRequest.PacketNumber, newRequest.Priority);
+
+                        //Check the packet sequence to make sure this isn't older than 
+                        //one we've already received
+                        if (newRequest.requestSequence > imgrequest.LastSequence)
+                        {
+                            //Update the sequence number of the last RequestImage packet
+                            imgrequest.LastSequence = newRequest.requestSequence;
+
+                            //Update the requested discard level
+                            imgrequest.DiscardLevel = newRequest.DiscardLevel;
+
+                            //Update the requested packet number
+                            imgrequest.StartPacket = Math.Max(1, newRequest.PacketNumber);
+
+                            //Update the requested priority
+                            imgrequest.Priority = newRequest.Priority;
+                            UpdateImageInQueue(imgrequest);
+
+                            //Run an update
+                            imgrequest.RunUpdate();
+                        }
+                    }
+                }
+                else
+                {
+                    if (newRequest.DiscardLevel == -1 && newRequest.Priority == 0f)
+                    {
+                        //m_log.DebugFormat("[TEX]: (IGN) ID={0}: D={1}, S={2}, P={3}",
+                        //    newRequest.RequestedAssetID, newRequest.DiscardLevel, newRequest.PacketNumber, newRequest.Priority);
+                    }
+                    else
+                    {
+                        //m_log.DebugFormat("[TEX]: (NEW) ID={0}: D={1}, S={2}, P={3}",
+                        //    newRequest.RequestedAssetID, newRequest.DiscardLevel, newRequest.PacketNumber, newRequest.Priority);
+
+                        imgrequest = new J2KImage(this);
+                        imgrequest.J2KDecoder = m_j2kDecodeModule;
+                        imgrequest.AssetService = m_assetCache;
+                        imgrequest.AgentID = m_client.AgentId;
+                        imgrequest.InventoryAccessModule = m_client.Scene.RequestModuleInterface<IInventoryAccessModule>();
+                        imgrequest.DiscardLevel = newRequest.DiscardLevel;
+                        imgrequest.StartPacket = Math.Max(1, newRequest.PacketNumber);
+                        imgrequest.Priority = newRequest.Priority;
+                        imgrequest.TextureID = newRequest.RequestedAssetID;
+                        imgrequest.Priority = newRequest.Priority;
+
+                        //Add this download to the priority queue
+                        AddImageToQueue(imgrequest);
+
+                        //Run an update
+                        imgrequest.RunUpdate();
+                    }
+                }
+            }
+        }
+
+        public bool ProcessImageQueue(int packetsToSend)
+        {
+            int packetsSent = 0;
+
+            while (packetsSent < packetsToSend)
+            {
+                J2KImage image = GetHighestPriorityImage();
+
+                // If null was returned, the texture priority queue is currently empty
+                if (image == null)
+                    return false;
+
+                if (image.IsDecoded)
+                {
+                    int sent;
+                    bool imageDone = image.SendPackets(m_client, packetsToSend - packetsSent, out sent);
+                    packetsSent += sent;
+
+                    // If the send is complete, destroy any knowledge of this transfer
+                    if (imageDone)
+                        RemoveImageFromQueue(image);
+                }
+                else
+                {
+                    // TODO: This is a limitation of how LLImageManager is currently
+                    // written. Undecoded textures should not be going into the priority
+                    // queue, because a high priority undecoded texture will clog up the
+                    // pipeline for a client
+                    return true;
+                }
+            }
+
+            return m_priorityQueue.Count > 0;
+        }
+
+        /// <summary>
+        /// Faux destructor
+        /// </summary>
+        public void Close()
+        {
+            m_shuttingdown = true;
+        }
+
+        #region Priority Queue Helpers
+
+        J2KImage GetHighestPriorityImage()
+        {
+            J2KImage image = null;
+
+            lock (m_syncRoot)
+            {
+                if (m_priorityQueue.Count > 0)
+                {
+                    try { image = m_priorityQueue.FindMax(); }
+                    catch (Exception) { }
+                }
+            }
+            return image;
+        }
+
+        void AddImageToQueue(J2KImage image)
+        {
+            image.PriorityQueueHandle = null;
+
+            lock (m_syncRoot)
+                try { m_priorityQueue.Add(ref image.PriorityQueueHandle, image); }
+                catch (Exception) { }
+        }
+
+        void RemoveImageFromQueue(J2KImage image)
+        {
+            lock (m_syncRoot)
+                try { m_priorityQueue.Delete(image.PriorityQueueHandle); }
+                catch (Exception) { }
+        }
+
+        void UpdateImageInQueue(J2KImage image)
+        {
+            lock (m_syncRoot)
+            {
+                try { m_priorityQueue.Replace(image.PriorityQueueHandle, image); }
+                catch (Exception)
+                {
+                    image.PriorityQueueHandle = null;
+                    m_priorityQueue.Add(ref image.PriorityQueueHandle, image);
+                }
+            }
+        }
+
+        #endregion Priority Queue Helpers
+    }
+}

OpenSim/Region/ClientStack/Linden/UDP/LLUDPClient.cs

@@ -0,0 +1,697 @@
+/*
+ * 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.Threading;
+using log4net;
+using OpenSim.Framework;
+using OpenMetaverse;
+using OpenMetaverse.Packets;
+
+using TokenBucket = OpenSim.Region.ClientStack.LindenUDP.TokenBucket;
+
+namespace OpenSim.Region.ClientStack.LindenUDP
+{
+    #region Delegates
+
+    /// <summary>
+    /// Fired when updated networking stats are produced for this client
+    /// </summary>
+    /// <param name="inPackets">Number of incoming packets received since this
+    /// event was last fired</param>
+    /// <param name="outPackets">Number of outgoing packets sent since this
+    /// event was last fired</param>
+    /// <param name="unAckedBytes">Current total number of bytes in packets we
+    /// are waiting on ACKs for</param>
+    public delegate void PacketStats(int inPackets, int outPackets, int unAckedBytes);
+    /// <summary>
+    /// Fired when the queue for one or more packet categories is empty. This 
+    /// event can be hooked to put more data on the empty queues
+    /// </summary>
+    /// <param name="category">Categories of the packet queues that are empty</param>
+    public delegate void QueueEmpty(ThrottleOutPacketTypeFlags categories);
+
+    #endregion Delegates
+
+    /// <summary>
+    /// Tracks state for a client UDP connection and provides client-specific methods
+    /// </summary>
+    public sealed class LLUDPClient
+    {
+        // TODO: Make this a config setting
+        /// <summary>Percentage of the task throttle category that is allocated to avatar and prim
+        /// state updates</summary>
+        const float STATE_TASK_PERCENTAGE = 0.8f;
+
+        private static readonly ILog m_log = LogManager.GetLogger(System.Reflection.MethodBase.GetCurrentMethod().DeclaringType);
+
+        /// <summary>The number of packet categories to throttle on. If a throttle category is added
+        /// or removed, this number must also change</summary>
+        const int THROTTLE_CATEGORY_COUNT = 8;
+
+        /// <summary>Fired when updated networking stats are produced for this client</summary>
+        public event PacketStats OnPacketStats;
+        /// <summary>Fired when the queue for a packet category is empty. This event can be
+        /// hooked to put more data on the empty queue</summary>
+        public event QueueEmpty OnQueueEmpty;
+
+        /// <summary>AgentID for this client</summary>
+        public readonly UUID AgentID;
+        /// <summary>The remote address of the connected client</summary>
+        public readonly IPEndPoint RemoteEndPoint;
+        /// <summary>Circuit code that this client is connected on</summary>
+        public readonly uint CircuitCode;
+        /// <summary>Sequence numbers of packets we've received (for duplicate checking)</summary>
+        public readonly IncomingPacketHistoryCollection PacketArchive = new IncomingPacketHistoryCollection(200);
+        /// <summary>Packets we have sent that need to be ACKed by the client</summary>
+        public readonly UnackedPacketCollection NeedAcks = new UnackedPacketCollection();
+        /// <summary>ACKs that are queued up, waiting to be sent to the client</summary>
+        public readonly OpenSim.Framework.LocklessQueue<uint> PendingAcks = new OpenSim.Framework.LocklessQueue<uint>();
+
+        /// <summary>Current packet sequence number</summary>
+        public int CurrentSequence;
+        /// <summary>Current ping sequence number</summary>
+        public byte CurrentPingSequence;
+        /// <summary>True when this connection is alive, otherwise false</summary>
+        public bool IsConnected = true;
+        /// <summary>True when this connection is paused, otherwise false</summary>
+        public bool IsPaused;
+        /// <summary>Environment.TickCount when the last packet was received for this client</summary>
+        public int TickLastPacketReceived;
+
+        /// <summary>Smoothed round-trip time. A smoothed average of the round-trip time for sending a
+        /// reliable packet to the client and receiving an ACK</summary>
+        public float SRTT;
+        /// <summary>Round-trip time variance. Measures the consistency of round-trip times</summary>
+        public float RTTVAR;
+        /// <summary>Retransmission timeout. Packets that have not been acknowledged in this number of
+        /// milliseconds or longer will be resent</summary>
+        /// <remarks>Calculated from <seealso cref="SRTT"/> and <seealso cref="RTTVAR"/> using the
+        /// guidelines in RFC 2988</remarks>
+        public int RTO;
+        /// <summary>Number of bytes received since the last acknowledgement was sent out. This is used
+        /// to loosely follow the TCP delayed ACK algorithm in RFC 1122 (4.2.3.2)</summary>
+        public int BytesSinceLastACK;
+        /// <summary>Number of packets received from this client</summary>
+        public int PacketsReceived;
+        /// <summary>Number of packets sent to this client</summary>
+        public int PacketsSent;
+        /// <summary>Number of packets resent to this client</summary>
+        public int PacketsResent;        
+        /// <summary>Total byte count of unacked packets sent to this client</summary>
+        public int UnackedBytes;
+
+        /// <summary>Total number of received packets that we have reported to the OnPacketStats event(s)</summary>
+        private int m_packetsReceivedReported;
+        /// <summary>Total number of sent packets that we have reported to the OnPacketStats event(s)</summary>
+        private int m_packetsSentReported;
+        /// <summary>Holds the Environment.TickCount value of when the next OnQueueEmpty can be fired</summary>
+        private int m_nextOnQueueEmpty = 1;
+
+        /// <summary>Throttle bucket for this agent's connection</summary>
+        private readonly AdaptiveTokenBucket m_throttleClient;
+        public AdaptiveTokenBucket FlowThrottle
+        {
+            get { return m_throttleClient; }
+        }
+
+        /// <summary>Throttle bucket for this agent's connection</summary>
+        private readonly TokenBucket m_throttleCategory;
+        /// <summary>Throttle buckets for each packet category</summary>
+        private readonly TokenBucket[] m_throttleCategories;
+        /// <summary>Outgoing queues for throttled packets</summary>
+        private readonly OpenSim.Framework.LocklessQueue<OutgoingPacket>[] m_packetOutboxes = new OpenSim.Framework.LocklessQueue<OutgoingPacket>[THROTTLE_CATEGORY_COUNT];
+        /// <summary>A container that can hold one packet for each outbox, used to store
+        /// dequeued packets that are being held for throttling</summary>
+        private readonly OutgoingPacket[] m_nextPackets = new OutgoingPacket[THROTTLE_CATEGORY_COUNT];
+        /// <summary>A reference to the LLUDPServer that is managing this client</summary>
+        private readonly LLUDPServer m_udpServer;
+
+        /// <summary>Caches packed throttle information</summary>
+        private byte[] m_packedThrottles;
+
+        private int m_defaultRTO = 1000; // 1sec is the recommendation in the RFC
+        private int m_maxRTO = 60000;
+
+        /// <summary>
+        /// Default constructor
+        /// </summary>
+        /// <param name="server">Reference to the UDP server this client is connected to</param>
+        /// <param name="rates">Default throttling rates and maximum throttle limits</param>
+        /// <param name="parentThrottle">Parent HTB (hierarchical token bucket)
+        /// that the child throttles will be governed by</param>
+        /// <param name="circuitCode">Circuit code for this connection</param>
+        /// <param name="agentID">AgentID for the connected agent</param>
+        /// <param name="remoteEndPoint">Remote endpoint for this connection</param>
+        public LLUDPClient(LLUDPServer server, ThrottleRates rates, TokenBucket parentThrottle, uint circuitCode, UUID agentID, IPEndPoint remoteEndPoint, int defaultRTO, int maxRTO)
+        {
+            AgentID = agentID;
+            RemoteEndPoint = remoteEndPoint;
+            CircuitCode = circuitCode;
+            m_udpServer = server;
+            if (defaultRTO != 0)
+                m_defaultRTO = defaultRTO;
+            if (maxRTO != 0)
+                m_maxRTO = maxRTO;
+
+            // Create a token bucket throttle for this client that has the scene token bucket as a parent
+            m_throttleClient = new AdaptiveTokenBucket(parentThrottle, rates.Total, rates.AdaptiveThrottlesEnabled);
+            // Create a token bucket throttle for the total categary with the client bucket as a throttle
+            m_throttleCategory = new TokenBucket(m_throttleClient, 0);
+            // Create an array of token buckets for this clients different throttle categories
+            m_throttleCategories = new TokenBucket[THROTTLE_CATEGORY_COUNT];
+
+            for (int i = 0; i < THROTTLE_CATEGORY_COUNT; i++)
+            {
+                ThrottleOutPacketType type = (ThrottleOutPacketType)i;
+
+                // Initialize the packet outboxes, where packets sit while they are waiting for tokens
+                m_packetOutboxes[i] = new OpenSim.Framework.LocklessQueue<OutgoingPacket>();
+                // Initialize the token buckets that control the throttling for each category
+                m_throttleCategories[i] = new TokenBucket(m_throttleCategory, rates.GetRate(type));
+            }
+
+            // Default the retransmission timeout to three seconds
+            RTO = m_defaultRTO;
+
+            // Initialize this to a sane value to prevent early disconnects
+            TickLastPacketReceived = Environment.TickCount & Int32.MaxValue;
+        }
+
+        /// <summary>
+        /// Shuts down this client connection
+        /// </summary>
+        public void Shutdown()
+        {
+            IsConnected = false;
+            for (int i = 0; i < THROTTLE_CATEGORY_COUNT; i++)
+            {
+                m_packetOutboxes[i].Clear();
+                m_nextPackets[i] = null;
+            }
+
+            // pull the throttle out of the scene throttle
+            m_throttleClient.Parent.UnregisterRequest(m_throttleClient);
+            OnPacketStats = null;
+            OnQueueEmpty = null;
+        }
+
+        /// <summary>
+        /// Gets information about this client connection
+        /// </summary>
+        /// <returns>Information about the client connection</returns>
+        public ClientInfo GetClientInfo()
+        {
+            // TODO: This data structure is wrong in so many ways. Locking and copying the entire lists
+            // of pending and needed ACKs for every client every time some method wants information about
+            // this connection is a recipe for poor performance
+            ClientInfo info = new ClientInfo();
+            info.pendingAcks = new Dictionary<uint, uint>();
+            info.needAck = new Dictionary<uint, byte[]>();
+
+            info.resendThrottle = (int)m_throttleCategories[(int)ThrottleOutPacketType.Resend].DripRate;
+            info.landThrottle = (int)m_throttleCategories[(int)ThrottleOutPacketType.Land].DripRate;
+            info.windThrottle = (int)m_throttleCategories[(int)ThrottleOutPacketType.Wind].DripRate;
+            info.cloudThrottle = (int)m_throttleCategories[(int)ThrottleOutPacketType.Cloud].DripRate;
+            info.taskThrottle = (int)m_throttleCategories[(int)ThrottleOutPacketType.Task].DripRate;
+            info.assetThrottle = (int)m_throttleCategories[(int)ThrottleOutPacketType.Asset].DripRate;
+            info.textureThrottle = (int)m_throttleCategories[(int)ThrottleOutPacketType.Texture].DripRate;
+            info.totalThrottle = (int)m_throttleCategory.DripRate;
+
+            return info;
+        }
+
+        /// <summary>
+        /// Modifies the UDP throttles
+        /// </summary>
+        /// <param name="info">New throttling values</param>
+        public void SetClientInfo(ClientInfo info)
+        {
+            // TODO: Allowing throttles to be manually set from this function seems like a reasonable
+            // idea. On the other hand, letting external code manipulate our ACK accounting is not
+            // going to happen
+            throw new NotImplementedException();
+        }
+
+        /// <summary>
+        /// Return statistics information about client packet queues.
+        /// </summary>
+        /// 
+        /// FIXME: This should really be done in a more sensible manner rather than sending back a formatted string.
+        /// 
+        /// <returns></returns>
+        public string GetStats()
+        {
+            return string.Format(
+                "{0,7} {1,7} {2,7} {3,9} {4,7} {5,7} {6,7} {7,7} {8,7} {9,8} {10,7} {11,7}",
+                PacketsReceived,                                 
+                PacketsSent,
+                PacketsResent,
+                UnackedBytes,
+                m_packetOutboxes[(int)ThrottleOutPacketType.Resend].Count,
+                m_packetOutboxes[(int)ThrottleOutPacketType.Land].Count,
+                m_packetOutboxes[(int)ThrottleOutPacketType.Wind].Count,
+                m_packetOutboxes[(int)ThrottleOutPacketType.Cloud].Count,
+                m_packetOutboxes[(int)ThrottleOutPacketType.Task].Count,
+                m_packetOutboxes[(int)ThrottleOutPacketType.Texture].Count,
+                m_packetOutboxes[(int)ThrottleOutPacketType.Asset].Count,
+                m_packetOutboxes[(int)ThrottleOutPacketType.State].Count);                                
+        }
+
+        public void SendPacketStats()
+        {
+            PacketStats callback = OnPacketStats;
+            if (callback != null)
+            {
+                int newPacketsReceived = PacketsReceived - m_packetsReceivedReported;
+                int newPacketsSent = PacketsSent - m_packetsSentReported;
+
+                callback(newPacketsReceived, newPacketsSent, UnackedBytes);
+
+                m_packetsReceivedReported += newPacketsReceived;
+                m_packetsSentReported += newPacketsSent;
+            }
+        }
+
+        public void SetThrottles(byte[] throttleData)
+        {
+            byte[] adjData;
+            int pos = 0;
+
+            if (!BitConverter.IsLittleEndian)
+            {
+                byte[] newData = new byte[7 * 4];
+                Buffer.BlockCopy(throttleData, 0, newData, 0, 7 * 4);
+
+                for (int i = 0; i < 7; i++)
+                    Array.Reverse(newData, i * 4, 4);
+
+                adjData = newData;
+            }
+            else
+            {
+                adjData = throttleData;
+            }
+
+            // 0.125f converts from bits to bytes
+            int resend = (int)(BitConverter.ToSingle(adjData, pos) * 0.125f); pos += 4;
+            int land = (int)(BitConverter.ToSingle(adjData, pos) * 0.125f); pos += 4;
+            int wind = (int)(BitConverter.ToSingle(adjData, pos) * 0.125f); pos += 4;
+            int cloud = (int)(BitConverter.ToSingle(adjData, pos) * 0.125f); pos += 4;
+            int task = (int)(BitConverter.ToSingle(adjData, pos) * 0.125f); pos += 4;
+            int texture = (int)(BitConverter.ToSingle(adjData, pos) * 0.125f); pos += 4;
+            int asset = (int)(BitConverter.ToSingle(adjData, pos) * 0.125f);
+            // State is a subcategory of task that we allocate a percentage to
+            int state = 0;
+
+            // Make sure none of the throttles are set below our packet MTU,
+            // otherwise a throttle could become permanently clogged
+            resend = Math.Max(resend, LLUDPServer.MTU);
+            land = Math.Max(land, LLUDPServer.MTU);
+            wind = Math.Max(wind, LLUDPServer.MTU);
+            cloud = Math.Max(cloud, LLUDPServer.MTU);
+            task = Math.Max(task, LLUDPServer.MTU);
+            texture = Math.Max(texture, LLUDPServer.MTU);
+            asset = Math.Max(asset, LLUDPServer.MTU);
+
+            //int total = resend + land + wind + cloud + task + texture + asset;
+            //m_log.DebugFormat("[LLUDPCLIENT]: {0} is setting throttles. Resend={1}, Land={2}, Wind={3}, Cloud={4}, Task={5}, Texture={6}, Asset={7}, Total={8}",
+            //                  AgentID, resend, land, wind, cloud, task, texture, asset, total);
+
+            // Update the token buckets with new throttle values
+            TokenBucket bucket;
+
+            bucket = m_throttleCategories[(int)ThrottleOutPacketType.Resend];
+            bucket.RequestedDripRate = resend;
+
+            bucket = m_throttleCategories[(int)ThrottleOutPacketType.Land];
+            bucket.RequestedDripRate = land;
+
+            bucket = m_throttleCategories[(int)ThrottleOutPacketType.Wind];
+            bucket.RequestedDripRate = wind;
+
+            bucket = m_throttleCategories[(int)ThrottleOutPacketType.Cloud];
+            bucket.RequestedDripRate = cloud;
+
+            bucket = m_throttleCategories[(int)ThrottleOutPacketType.Asset];
+            bucket.RequestedDripRate = asset;
+
+            bucket = m_throttleCategories[(int)ThrottleOutPacketType.Task];
+            bucket.RequestedDripRate = task;
+
+            bucket = m_throttleCategories[(int)ThrottleOutPacketType.State];
+            bucket.RequestedDripRate = state;
+
+            bucket = m_throttleCategories[(int)ThrottleOutPacketType.Texture];
+            bucket.RequestedDripRate = texture;
+
+            // Reset the packed throttles cached data
+            m_packedThrottles = null;
+        }
+
+        public byte[] GetThrottlesPacked(float multiplier)
+        {
+            byte[] data = m_packedThrottles;
+
+            if (data == null)
+            {
+                float rate;
+
+                data = new byte[7 * 4];
+                int i = 0;
+
+                // multiply by 8 to convert bytes back to bits
+                rate = (float)m_throttleCategories[(int)ThrottleOutPacketType.Resend].RequestedDripRate * 8 * multiplier;
+                Buffer.BlockCopy(Utils.FloatToBytes(rate), 0, data, i, 4); i += 4;
+
+                rate = (float)m_throttleCategories[(int)ThrottleOutPacketType.Land].RequestedDripRate * 8 * multiplier;
+                Buffer.BlockCopy(Utils.FloatToBytes(rate), 0, data, i, 4); i += 4;
+
+                rate = (float)m_throttleCategories[(int)ThrottleOutPacketType.Wind].RequestedDripRate * 8 * multiplier;
+                Buffer.BlockCopy(Utils.FloatToBytes(rate), 0, data, i, 4); i += 4;
+
+                rate = (float)m_throttleCategories[(int)ThrottleOutPacketType.Cloud].RequestedDripRate * 8 * multiplier;
+                Buffer.BlockCopy(Utils.FloatToBytes(rate), 0, data, i, 4); i += 4;
+
+                rate = (float)m_throttleCategories[(int)ThrottleOutPacketType.Task].RequestedDripRate * 8 * multiplier;
+                Buffer.BlockCopy(Utils.FloatToBytes(rate), 0, data, i, 4); i += 4;
+
+                rate = (float)m_throttleCategories[(int)ThrottleOutPacketType.Texture].RequestedDripRate * 8 * multiplier;
+                Buffer.BlockCopy(Utils.FloatToBytes(rate), 0, data, i, 4); i += 4;
+
+                rate = (float)m_throttleCategories[(int)ThrottleOutPacketType.Asset].RequestedDripRate * 8 * multiplier;
+                Buffer.BlockCopy(Utils.FloatToBytes(rate), 0, data, i, 4); i += 4;
+
+                m_packedThrottles = data;
+            }
+
+            return data;
+        }
+
+        /// <summary>
+        /// Queue an outgoing packet if appropriate.
+        /// </summary>
+        /// <param name="packet"></param>
+        /// <param name="forceQueue">Always queue the packet if at all possible.</param>
+        /// <returns>
+        /// true if the packet has been queued, 
+        /// false if the packet has not been queued and should be sent immediately.
+        /// </returns>
+        public bool EnqueueOutgoing(OutgoingPacket packet, bool forceQueue)
+        {
+            int category = (int)packet.Category;
+
+            if (category >= 0 && category < m_packetOutboxes.Length)
+            {
+                OpenSim.Framework.LocklessQueue<OutgoingPacket> queue = m_packetOutboxes[category];
+                TokenBucket bucket = m_throttleCategories[category];
+
+                // Don't send this packet if there is already a packet waiting in the queue
+                // even if we have the tokens to send it, tokens should go to the already
+                // queued packets
+                if (queue.Count > 0)
+                {
+                    queue.Enqueue(packet);
+                    return true;
+                }
+                
+                    
+                if (!forceQueue && bucket.RemoveTokens(packet.Buffer.DataLength))
+                {
+                    // Enough tokens were removed from the bucket, the packet will not be queued
+                    return false;
+                }
+                else
+                {
+                    // Force queue specified or not enough tokens in the bucket, queue this packet
+                    queue.Enqueue(packet);
+                    return true;
+                }
+            }
+            else
+            {
+                // We don't have a token bucket for this category, so it will not be queued
+                return false;
+            }
+        }
+
+        /// <summary>
+        /// Loops through all of the packet queues for this client and tries to send
+        /// an outgoing packet from each, obeying the throttling bucket limits
+        /// </summary>
+        /// 
+        /// <remarks>
+        /// Packet queues are inspected in ascending numerical order starting from 0.  Therefore, queues with a lower 
+        /// ThrottleOutPacketType number will see their packet get sent first (e.g. if both Land and Wind queues have
+        /// packets, then the packet at the front of the Land queue will be sent before the packet at the front of the
+        /// wind queue).
+        /// 
+        /// This function is only called from a synchronous loop in the
+        /// UDPServer so we don't need to bother making this thread safe
+        /// </remarks>
+        /// 
+        /// <returns>True if any packets were sent, otherwise false</returns>
+        public bool DequeueOutgoing()
+        {
+            OutgoingPacket packet;
+            OpenSim.Framework.LocklessQueue<OutgoingPacket> queue;
+            TokenBucket bucket;
+            bool packetSent = false;
+            ThrottleOutPacketTypeFlags emptyCategories = 0;
+
+            //string queueDebugOutput = String.Empty; // Serious debug business
+
+            for (int i = 0; i < THROTTLE_CATEGORY_COUNT; i++)
+            {
+                bucket = m_throttleCategories[i];
+                //queueDebugOutput += m_packetOutboxes[i].Count + " ";  // Serious debug business
+
+                if (m_nextPackets[i] != null)
+                {
+                    // This bucket was empty the last time we tried to send a packet,
+                    // leaving a dequeued packet still waiting to be sent out. Try to
+                    // send it again
+                    OutgoingPacket nextPacket = m_nextPackets[i];
+                    if (bucket.RemoveTokens(nextPacket.Buffer.DataLength))
+                    {
+                        // Send the packet
+                        m_udpServer.SendPacketFinal(nextPacket);
+                        m_nextPackets[i] = null;
+                        packetSent = true;
+                    }
+                }
+                else
+                {
+                    // No dequeued packet waiting to be sent, try to pull one off
+                    // this queue
+                    queue = m_packetOutboxes[i];
+                    if (queue.Dequeue(out packet))
+                    {
+                        // A packet was pulled off the queue. See if we have
+                        // enough tokens in the bucket to send it out
+                        if (bucket.RemoveTokens(packet.Buffer.DataLength))
+                        {
+                            // Send the packet
+                            m_udpServer.SendPacketFinal(packet);
+                            packetSent = true;
+                        }
+                        else
+                        {
+                            // Save the dequeued packet for the next iteration
+                            m_nextPackets[i] = packet;
+                        }
+
+                        // If the queue is empty after this dequeue, fire the queue
+                        // empty callback now so it has a chance to fill before we 
+                        // get back here
+                        if (queue.Count == 0)
+                            emptyCategories |= CategoryToFlag(i);
+                    }
+                    else
+                    {
+                        // No packets in this queue. Fire the queue empty callback
+                        // if it has not been called recently
+                        emptyCategories |= CategoryToFlag(i);
+                    }
+                }
+            }
+
+            if (emptyCategories != 0)
+                BeginFireQueueEmpty(emptyCategories);
+
+            //m_log.Info("[LLUDPCLIENT]: Queues: " + queueDebugOutput); // Serious debug business
+            return packetSent;
+        }
+
+        /// <summary>
+        /// Called when an ACK packet is received and a round-trip time for a
+        /// packet is calculated. This is used to calculate the smoothed
+        /// round-trip time, round trip time variance, and finally the
+        /// retransmission timeout
+        /// </summary>
+        /// <param name="r">Round-trip time of a single packet and its
+        /// acknowledgement</param>
+        public void UpdateRoundTrip(float r)
+        {
+            const float ALPHA = 0.125f;
+            const float BETA = 0.25f;
+            const float K = 4.0f;
+
+            if (RTTVAR == 0.0f)
+            {
+                // First RTT measurement
+                SRTT = r;
+                RTTVAR = r * 0.5f;
+            }
+            else
+            {
+                // Subsequence RTT measurement
+                RTTVAR = (1.0f - BETA) * RTTVAR + BETA * Math.Abs(SRTT - r);
+                SRTT = (1.0f - ALPHA) * SRTT + ALPHA * r;
+            }
+
+            int rto = (int)(SRTT + Math.Max(m_udpServer.TickCountResolution, K * RTTVAR));
+
+            // Clamp the retransmission timeout to manageable values
+            rto = Utils.Clamp(rto, m_defaultRTO, m_maxRTO);
+
+            RTO = rto;
+
+            //m_log.Debug("[LLUDPCLIENT]: Setting agent " + this.Agent.FullName + "'s RTO to " + RTO + "ms with an RTTVAR of " +
+            //    RTTVAR + " based on new RTT of " + r + "ms");
+        }
+
+        /// <summary>
+        /// Exponential backoff of the retransmission timeout, per section 5.5
+        /// of RFC 2988
+        /// </summary>
+        public void BackoffRTO()
+        {
+            // Reset SRTT and RTTVAR, we assume they are bogus since things
+            // didn't work out and we're backing off the timeout
+            SRTT = 0.0f;
+            RTTVAR = 0.0f;
+
+            // Double the retransmission timeout
+            RTO = Math.Min(RTO * 2, m_maxRTO);
+        }
+
+        /// <summary>
+        /// Does an early check to see if this queue empty callback is already
+        /// running, then asynchronously firing the event
+        /// </summary>
+        /// <param name="throttleIndex">Throttle category to fire the callback
+        /// for</param>
+        private void BeginFireQueueEmpty(ThrottleOutPacketTypeFlags categories)
+        {
+            if (m_nextOnQueueEmpty != 0 && (Environment.TickCount & Int32.MaxValue) >= m_nextOnQueueEmpty)
+            {
+                // Use a value of 0 to signal that FireQueueEmpty is running
+                m_nextOnQueueEmpty = 0;
+                // Asynchronously run the callback
+                Util.FireAndForget(FireQueueEmpty, categories);
+            }
+        }
+
+        /// <summary>
+        /// Fires the OnQueueEmpty callback and sets the minimum time that it
+        /// can be called again
+        /// </summary>
+        /// <param name="o">Throttle categories to fire the callback for,
+        /// stored as an object to match the WaitCallback delegate
+        /// signature</param>
+        private void FireQueueEmpty(object o)
+        {
+            const int MIN_CALLBACK_MS = 30;
+
+            ThrottleOutPacketTypeFlags categories = (ThrottleOutPacketTypeFlags)o;
+            QueueEmpty callback = OnQueueEmpty;
+            
+            int start = Environment.TickCount & Int32.MaxValue;
+
+            if (callback != null)
+            {
+                try { callback(categories); }
+                catch (Exception e) { m_log.Error("[LLUDPCLIENT]: OnQueueEmpty(" + categories + ") threw an exception: " + e.Message, e); }
+            }
+
+            m_nextOnQueueEmpty = start + MIN_CALLBACK_MS;
+            if (m_nextOnQueueEmpty == 0)
+                m_nextOnQueueEmpty = 1;
+        }
+
+        /// <summary>
+        /// Converts a <seealso cref="ThrottleOutPacketType"/> integer to a
+        /// flag value
+        /// </summary>
+        /// <param name="i">Throttle category to convert</param>
+        /// <returns>Flag representation of the throttle category</returns>
+        private static ThrottleOutPacketTypeFlags CategoryToFlag(int i)
+        {
+            ThrottleOutPacketType category = (ThrottleOutPacketType)i;
+
+            /*
+             * Land = 1,
+        /// <summary>Wind data</summary>
+        Wind = 2,
+        /// <summary>Cloud data</summary>
+        Cloud = 3,
+        /// <summary>Any packets that do not fit into the other throttles</summary>
+        Task = 4,
+        /// <summary>Texture assets</summary>
+        Texture = 5,
+        /// <summary>Non-texture assets</summary>
+        Asset = 6,
+        /// <summary>Avatar and primitive data</summary>
+        /// <remarks>This is a sub-category of Task</remarks>
+        State = 7,
+             */
+
+            switch (category)
+            {
+                case ThrottleOutPacketType.Land:
+                    return ThrottleOutPacketTypeFlags.Land;
+                case ThrottleOutPacketType.Wind:
+                    return ThrottleOutPacketTypeFlags.Wind;
+                case ThrottleOutPacketType.Cloud:
+                    return ThrottleOutPacketTypeFlags.Cloud;
+                case ThrottleOutPacketType.Task:
+                    return ThrottleOutPacketTypeFlags.Task;
+                case ThrottleOutPacketType.Texture:
+                    return ThrottleOutPacketTypeFlags.Texture;
+                case ThrottleOutPacketType.Asset:
+                    return ThrottleOutPacketTypeFlags.Asset;
+                case ThrottleOutPacketType.State:
+                    return ThrottleOutPacketTypeFlags.State;
+                default:
+                    return 0;
+            }
+        }
+    }
+}

OpenSim/Region/ClientStack/Linden/UDP/OpenSimUDPBase.cs

@@ -0,0 +1,284 @@
+/*
+ * Copyright (c) 2006, Clutch, Inc.
+ * Original Author: Jeff Cesnik
+ * All rights reserved.
+ *
+ * - 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.
+ * - Neither the name of the openmetaverse.org 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 COPYRIGHT HOLDERS AND CONTRIBUTORS "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 COPYRIGHT OWNER OR 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.Net;
+using System.Net.Sockets;
+using System.Threading;
+using log4net;
+
+namespace OpenMetaverse
+{
+    /// <summary>
+    /// Base UDP server
+    /// </summary>
+    public abstract class OpenSimUDPBase
+    {
+        private static readonly ILog m_log = LogManager.GetLogger(System.Reflection.MethodBase.GetCurrentMethod().DeclaringType);
+
+        /// <summary>
+        /// This method is called when an incoming packet is received
+        /// </summary>
+        /// <param name="buffer">Incoming packet buffer</param>
+        protected abstract void PacketReceived(UDPPacketBuffer buffer);
+
+        /// <summary>UDP port to bind to in server mode</summary>
+        protected int m_udpPort;
+
+        /// <summary>Local IP address to bind to in server mode</summary>
+        protected IPAddress m_localBindAddress;
+
+        /// <summary>UDP socket, used in either client or server mode</summary>
+        private Socket m_udpSocket;
+
+        /// <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>Returns true if the server is currently listening, otherwise false</summary>
+        public bool IsRunning { get { return !m_shutdownFlag; } }
+
+        /// <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>
+        public OpenSimUDPBase(IPAddress bindAddress, int port)
+        {
+            m_localBindAddress = bindAddress;
+            m_udpPort = port;
+        }
+
+        /// <summary>
+        /// Start the UDP server
+        /// </summary>
+        /// <param name="recvBufferSize">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</param>
+        /// <param name="asyncPacketHandling">Set this to true to start
+        /// receiving more packets while current packet handler callbacks are
+        /// still running. Setting this to false will complete each packet
+        /// callback before the next packet is processed</param>
+        /// <remarks>This method will attempt to set the SIO_UDP_CONNRESET flag
+        /// on the socket to get newer versions of Windows to behave in a sane
+        /// 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)
+        {
+            m_asyncPacketHandling = asyncPacketHandling;
+
+            if (m_shutdownFlag)
+            {
+                const int SIO_UDP_CONNRESET = -1744830452;
+
+                IPEndPoint ipep = new IPEndPoint(m_localBindAddress, m_udpPort);
+                
+                m_log.DebugFormat(
+                    "[UDPBASE]: Binding UDP listener using internal IP address config {0}:{1}", 
+                    ipep.Address, ipep.Port);                
+
+                m_udpSocket = new Socket(
+                    AddressFamily.InterNetwork,
+                    SocketType.Dgram,
+                    ProtocolType.Udp);
+
+                try
+                {
+                    // This udp socket flag is not supported under mono, 
+                    // so we'll catch the exception and continue
+                    m_udpSocket.IOControl(SIO_UDP_CONNRESET, new byte[] { 0 }, null);
+                    m_log.Debug("[UDPBASE]: SIO_UDP_CONNRESET flag set");
+                }
+                catch (SocketException)
+                {
+                    m_log.Debug("[UDPBASE]: SIO_UDP_CONNRESET flag not supported on this platform, ignoring");
+                }
+
+                if (recvBufferSize != 0)
+                    m_udpSocket.ReceiveBufferSize = recvBufferSize;
+
+                m_udpSocket.Bind(ipep);
+
+                // we're not shutting down, we're starting up
+                m_shutdownFlag = false;
+
+                // kick off an async receive.  The Start() method will return, the
+                // actual receives will occur asynchronously and will be caught in
+                // AsyncEndRecieve().
+                AsyncBeginReceive();
+            }
+        }
+
+        /// <summary>
+        /// Stops the UDP server
+        /// </summary>
+        public void Stop()
+        {
+            if (!m_shutdownFlag)
+            {
+                // 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 that the socket is closed.
+                m_shutdownFlag = true;
+                m_udpSocket.Close();
+            }
+        }
+
+        private void AsyncBeginReceive()
+        {
+            // allocate a packet buffer
+            //WrappedObject<UDPPacketBuffer> wrappedBuffer = Pool.CheckOut();
+            UDPPacketBuffer buf = new UDPPacketBuffer();
+
+            if (!m_shutdownFlag)
+            {
+                try
+                {
+                    // kick off an async read
+                    m_udpSocket.BeginReceiveFrom(
+                        //wrappedBuffer.Instance.Data,
+                        buf.Data,
+                        0,
+                        UDPPacketBuffer.BUFFER_SIZE,
+                        SocketFlags.None,
+                        ref buf.RemoteEndPoint,
+                        AsyncEndReceive,
+                        //wrappedBuffer);
+                        buf);
+                }
+                catch (SocketException e)
+                {
+                    if (e.SocketErrorCode == SocketError.ConnectionReset)
+                    {
+                        m_log.Warn("[UDPBASE]: SIO_UDP_CONNRESET was ignored, attempting to salvage the UDP listener on port " + m_udpPort);
+                        bool salvaged = false;
+                        while (!salvaged)
+                        {
+                            try
+                            {
+                                m_udpSocket.BeginReceiveFrom(
+                                    //wrappedBuffer.Instance.Data,
+                                    buf.Data,
+                                    0,
+                                    UDPPacketBuffer.BUFFER_SIZE,
+                                    SocketFlags.None,
+                                    ref buf.RemoteEndPoint,
+                                    AsyncEndReceive,
+                                    //wrappedBuffer);
+                                    buf);
+                                salvaged = true;
+                            }
+                            catch (SocketException) { }
+                            catch (ObjectDisposedException) { return; }
+                        }
+
+                        m_log.Warn("[UDPBASE]: Salvaged the UDP listener on port " + m_udpPort);
+                    }
+                }
+                catch (ObjectDisposedException) { }
+            }
+        }
+
+        private void AsyncEndReceive(IAsyncResult iar)
+        {
+            // Asynchronous receive operations will complete here through the call
+            // to AsyncBeginReceive
+            if (!m_shutdownFlag)
+            {
+                // Asynchronous mode will start another receive before the
+                // callback for this packet is even fired. Very parallel :-)
+                if (m_asyncPacketHandling)
+                    AsyncBeginReceive();
+
+                // 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
+                {
+                    // get the length of data actually read from the socket, store it with the
+                    // buffer
+                    buffer.DataLength = m_udpSocket.EndReceiveFrom(iar, ref buffer.RemoteEndPoint);
+
+                    // call the abstract method PacketReceived(), passing the buffer that
+                    // has just been filled from the socket read.
+                    PacketReceived(buffer);
+                }
+                catch (SocketException) { }
+                catch (ObjectDisposedException) { }
+                finally
+                {
+                    //wrappedBuffer.Dispose();
+
+                    // Synchronous mode waits until the packet callback completes
+                    // before starting the receive to fetch another packet
+                    if (!m_asyncPacketHandling)
+                        AsyncBeginReceive();
+                }
+
+            }
+        }
+
+        public void AsyncBeginSend(UDPPacketBuffer buf)
+        {
+            if (!m_shutdownFlag)
+            {
+                try
+                {
+                    m_udpSocket.BeginSendTo(
+                        buf.Data,
+                        0,
+                        buf.DataLength,
+                        SocketFlags.None,
+                        buf.RemoteEndPoint,
+                        AsyncEndSend,
+                        buf);
+                }
+                catch (SocketException) { }
+                catch (ObjectDisposedException) { }
+            }
+        }
+
+        void AsyncEndSend(IAsyncResult result)
+        {
+            try
+            {
+//                UDPPacketBuffer buf = (UDPPacketBuffer)result.AsyncState;
+                m_udpSocket.EndSendTo(result);
+            }
+            catch (SocketException) { }
+            catch (ObjectDisposedException) { }
+        }
+    }
+}

OpenSim/Region/ClientStack/Linden/UDP/OutgoingPacket.cs

@@ -0,0 +1,75 @@
+/*
+ * 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 OpenSim.Framework;
+using OpenMetaverse;
+
+namespace OpenSim.Region.ClientStack.LindenUDP
+{
+
+    public delegate void UnackedPacketMethod(OutgoingPacket oPacket);
+    /// <summary>
+    /// Holds a reference to the <seealso cref="LLUDPClient"/> this packet is
+    /// destined for, along with the serialized packet data, sequence number
+    /// (if this is a resend), number of times this packet has been resent,
+    /// the time of the last resend, and the throttling category for this
+    /// packet
+    /// </summary>
+    public sealed class OutgoingPacket
+    {
+        /// <summary>Client this packet is destined for</summary>
+        public LLUDPClient Client;
+        /// <summary>Packet data to send</summary>
+        public UDPPacketBuffer Buffer;
+        /// <summary>Sequence number of the wrapped packet</summary>
+        public uint SequenceNumber;
+        /// <summary>Number of times this packet has been resent</summary>
+        public int ResendCount;
+        /// <summary>Environment.TickCount when this packet was last sent over the wire</summary>
+        public int TickCount;
+        /// <summary>Category this packet belongs to</summary>
+        public ThrottleOutPacketType Category;
+        /// <summary>The delegate to be called if this packet is determined to be unacknowledged</summary>
+        public UnackedPacketMethod UnackedMethod;
+
+        /// <summary>
+        /// Default constructor
+        /// </summary>
+        /// <param name="client">Reference to the client this packet is destined for</param>
+        /// <param name="buffer">Serialized packet data. If the flags or sequence number
+        /// need to be updated, they will be injected directly into this binary buffer</param>
+        /// <param name="category">Throttling category for this packet</param>
+        public OutgoingPacket(LLUDPClient client, UDPPacketBuffer buffer, ThrottleOutPacketType category, UnackedPacketMethod method)
+        {
+            Client = client;
+            Buffer = buffer;
+            Category = category;
+            UnackedMethod = method;
+        }
+    }
+}

OpenSim/Region/ClientStack/Linden/UDP/Tests/BasicCircuitTests.cs

@@ -0,0 +1,299 @@
+/*
+ * 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.Net;
+using log4net.Config;
+using Nini.Config;
+using NUnit.Framework;
+using NUnit.Framework.SyntaxHelpers;
+using OpenMetaverse;
+using OpenMetaverse.Packets;
+using OpenSim.Framework;
+using OpenSim.Tests.Common;
+using OpenSim.Tests.Common.Mock;
+
+namespace OpenSim.Region.ClientStack.LindenUDP.Tests
+{
+    /// <summary>
+    /// This will contain basic tests for the LindenUDP client stack
+    /// </summary>
+    [TestFixture]
+    public class BasicCircuitTests
+    {
+        [SetUp]
+        public void Init()
+        {
+            try
+            {
+                XmlConfigurator.Configure();
+            }
+            catch
+            {
+                // I don't care, just leave log4net off
+            }
+        }
+        
+        /// <summary>
+        /// Add a client for testing
+        /// </summary>
+        /// <param name="scene"></param>
+        /// <param name="testLLUDPServer"></param>
+        /// <param name="testPacketServer"></param>
+        /// <param name="acm">Agent circuit manager used in setting up the stack</param>
+        protected void SetupStack(
+            IScene scene, out TestLLUDPServer testLLUDPServer, out TestLLPacketServer testPacketServer, 
+            out AgentCircuitManager acm)
+        {
+            IConfigSource configSource = new IniConfigSource();
+            ClientStackUserSettings userSettings = new ClientStackUserSettings();
+            testLLUDPServer = new TestLLUDPServer();
+            acm = new AgentCircuitManager();
+                                    
+            uint port = 666;
+            testLLUDPServer.Initialise(null, ref port, 0, false, configSource, acm);
+            testPacketServer = new TestLLPacketServer(testLLUDPServer, userSettings);
+            testLLUDPServer.LocalScene = scene;
+        }
+        
+        /// <summary>
+        /// Set up a client for tests which aren't concerned with this process itself and where only one client is being
+        /// tested
+        /// </summary>
+        /// <param name="circuitCode"></param>
+        /// <param name="epSender"></param>
+        /// <param name="testLLUDPServer"></param>
+        /// <param name="acm"></param>
+        protected void AddClient(
+            uint circuitCode, EndPoint epSender, TestLLUDPServer testLLUDPServer, AgentCircuitManager acm)
+        {
+            UUID myAgentUuid   = UUID.Parse("00000000-0000-0000-0000-000000000001");
+            UUID mySessionUuid = UUID.Parse("00000000-0000-0000-0000-000000000002");
+            
+            AddClient(circuitCode, epSender, myAgentUuid, mySessionUuid, testLLUDPServer, acm);
+        }
+        
+        /// <summary>
+        /// Set up a client for tests which aren't concerned with this process itself
+        /// </summary>
+        /// <param name="circuitCode"></param>
+        /// <param name="epSender"></param>
+        /// <param name="agentId"></param>
+        /// <param name="sessionId"></param>
+        /// <param name="testLLUDPServer"></param>
+        /// <param name="acm"></param>
+        protected void AddClient(
+            uint circuitCode, EndPoint epSender, UUID agentId, UUID sessionId, 
+            TestLLUDPServer testLLUDPServer, AgentCircuitManager acm)
+        {
+            AgentCircuitData acd = new AgentCircuitData();
+            acd.AgentID = agentId;
+            acd.SessionID = sessionId; 
+            
+            UseCircuitCodePacket uccp = new UseCircuitCodePacket();
+            
+            UseCircuitCodePacket.CircuitCodeBlock uccpCcBlock 
+                = new UseCircuitCodePacket.CircuitCodeBlock();
+            uccpCcBlock.Code = circuitCode;
+            uccpCcBlock.ID = agentId;
+            uccpCcBlock.SessionID = sessionId;
+            uccp.CircuitCode = uccpCcBlock;
+
+            acm.AddNewCircuit(circuitCode, acd);
+            
+            testLLUDPServer.LoadReceive(uccp, epSender);
+            testLLUDPServer.ReceiveData(null);
+        }
+        
+        /// <summary>
+        /// Build an object name packet for test purposes
+        /// </summary>
+        /// <param name="objectLocalId"></param>
+        /// <param name="objectName"></param>
+        protected ObjectNamePacket BuildTestObjectNamePacket(uint objectLocalId, string objectName)
+        {
+            ObjectNamePacket onp = new ObjectNamePacket();
+            ObjectNamePacket.ObjectDataBlock odb = new ObjectNamePacket.ObjectDataBlock();
+            odb.LocalID = objectLocalId;
+            odb.Name = Utils.StringToBytes(objectName);
+            onp.ObjectData = new ObjectNamePacket.ObjectDataBlock[] { odb };
+            onp.Header.Zerocoded = false;
+            
+            return onp;
+        }
+        
+        /// <summary>
+        /// Test adding a client to the stack
+        /// </summary>
+        [Test, LongRunning]
+        public void TestAddClient()
+        {
+            TestHelper.InMethod();
+
+            uint myCircuitCode = 123456;
+            UUID myAgentUuid   = UUID.Parse("00000000-0000-0000-0000-000000000001");
+            UUID mySessionUuid = UUID.Parse("00000000-0000-0000-0000-000000000002");
+            
+            TestLLUDPServer testLLUDPServer;
+            TestLLPacketServer testLLPacketServer;
+            AgentCircuitManager acm;
+            SetupStack(new MockScene(), out testLLUDPServer, out testLLPacketServer, out acm);
+            
+            AgentCircuitData acd = new AgentCircuitData();
+            acd.AgentID = myAgentUuid;
+            acd.SessionID = mySessionUuid;
+            
+            UseCircuitCodePacket uccp = new UseCircuitCodePacket();
+            
+            UseCircuitCodePacket.CircuitCodeBlock uccpCcBlock 
+                = new UseCircuitCodePacket.CircuitCodeBlock();
+            uccpCcBlock.Code = myCircuitCode;
+            uccpCcBlock.ID = myAgentUuid;
+            uccpCcBlock.SessionID = mySessionUuid;
+            uccp.CircuitCode = uccpCcBlock;
+            
+            EndPoint testEp = new IPEndPoint(IPAddress.Loopback, 999);
+            
+            testLLUDPServer.LoadReceive(uccp, testEp);
+            testLLUDPServer.ReceiveData(null);
+            
+            // Circuit shouildn't exist since the circuit manager doesn't know about this circuit for authentication yet
+            Assert.IsFalse(testLLUDPServer.HasCircuit(myCircuitCode));
+                        
+            acm.AddNewCircuit(myCircuitCode, acd);
+            
+            testLLUDPServer.LoadReceive(uccp, testEp);
+            testLLUDPServer.ReceiveData(null);
+            
+            // Should succeed now
+            Assert.IsTrue(testLLUDPServer.HasCircuit(myCircuitCode));
+            Assert.IsFalse(testLLUDPServer.HasCircuit(101));
+        }
+
+        /// <summary>
+        /// Test removing a client from the stack
+        /// </summary>
+        [Test]
+        public void TestRemoveClient()
+        {
+            TestHelper.InMethod();
+
+            uint myCircuitCode = 123457;
+            
+            TestLLUDPServer testLLUDPServer;
+            TestLLPacketServer testLLPacketServer;
+            AgentCircuitManager acm;
+            SetupStack(new MockScene(), out testLLUDPServer, out testLLPacketServer, out acm);
+            AddClient(myCircuitCode, new IPEndPoint(IPAddress.Loopback, 1000), testLLUDPServer, acm);
+            
+            testLLUDPServer.RemoveClientCircuit(myCircuitCode);
+            Assert.IsFalse(testLLUDPServer.HasCircuit(myCircuitCode));
+            
+            // Check that removing a non-existant circuit doesn't have any bad effects
+            testLLUDPServer.RemoveClientCircuit(101);
+            Assert.IsFalse(testLLUDPServer.HasCircuit(101));
+        }
+        
+        /// <summary>
+        /// Make sure that the client stack reacts okay to malformed packets
+        /// </summary>
+        [Test]
+        public void TestMalformedPacketSend()
+        {
+            TestHelper.InMethod();
+
+            uint myCircuitCode = 123458;
+            EndPoint testEp = new IPEndPoint(IPAddress.Loopback, 1001);
+            MockScene scene = new MockScene(); 
+            
+            TestLLUDPServer testLLUDPServer;
+            TestLLPacketServer testLLPacketServer;
+            AgentCircuitManager acm;
+            SetupStack(scene, out testLLUDPServer, out testLLPacketServer, out acm);
+            AddClient(myCircuitCode, testEp, testLLUDPServer, acm);
+
+            byte[] data = new byte[] { 0x01, 0x02, 0x03, 0x04 };
+
+            // Send two garbled 'packets' in succession
+            testLLUDPServer.LoadReceive(data, testEp);
+            testLLUDPServer.LoadReceive(data, testEp);
+            testLLUDPServer.ReceiveData(null); 
+            
+            // Check that we are still here
+            Assert.IsTrue(testLLUDPServer.HasCircuit(myCircuitCode));
+            Assert.That(testLLPacketServer.GetTotalPacketsReceived(), Is.EqualTo(0));
+            
+            // Check that sending a valid packet to same circuit still succeeds
+            Assert.That(scene.ObjectNameCallsReceived, Is.EqualTo(0));
+            
+            testLLUDPServer.LoadReceive(BuildTestObjectNamePacket(1, "helloooo"), testEp);
+            testLLUDPServer.ReceiveData(null);
+            
+            Assert.That(testLLPacketServer.GetTotalPacketsReceived(), Is.EqualTo(1));
+            Assert.That(testLLPacketServer.GetPacketsReceivedFor(PacketType.ObjectName), Is.EqualTo(1));
+        }
+        
+        /// <summary>
+        /// Test that the stack continues to work even if some client has caused a 
+        /// SocketException on Socket.BeginReceive()
+        /// </summary>
+        [Test]
+        public void TestExceptionOnBeginReceive()
+        {
+            TestHelper.InMethod();
+
+            MockScene scene = new MockScene();
+            
+            uint circuitCodeA = 130000;
+            EndPoint epA = new IPEndPoint(IPAddress.Loopback, 1300);
+            UUID agentIdA   = UUID.Parse("00000000-0000-0000-0000-000000001300");
+            UUID sessionIdA = UUID.Parse("00000000-0000-0000-0000-000000002300");
+            
+            uint circuitCodeB = 130001;
+            EndPoint epB = new IPEndPoint(IPAddress.Loopback, 1301);
+            UUID agentIdB   = UUID.Parse("00000000-0000-0000-0000-000000001301");
+            UUID sessionIdB = UUID.Parse("00000000-0000-0000-0000-000000002301");
+            
+            TestLLUDPServer testLLUDPServer;
+            TestLLPacketServer testLLPacketServer;
+            AgentCircuitManager acm;
+            SetupStack(scene, out testLLUDPServer, out testLLPacketServer, out acm);
+            AddClient(circuitCodeA, epA, agentIdA, sessionIdA, testLLUDPServer, acm);
+            AddClient(circuitCodeB, epB, agentIdB, sessionIdB, testLLUDPServer, acm);
+            
+            testLLUDPServer.LoadReceive(BuildTestObjectNamePacket(1, "packet1"), epA);
+            testLLUDPServer.LoadReceive(BuildTestObjectNamePacket(1, "packet2"), epB);
+            testLLUDPServer.LoadReceiveWithBeginException(epA);
+            testLLUDPServer.LoadReceive(BuildTestObjectNamePacket(2, "packet3"), epB);
+            testLLUDPServer.ReceiveData(null);
+            
+            Assert.IsFalse(testLLUDPServer.HasCircuit(circuitCodeA));
+         
+            Assert.That(testLLPacketServer.GetTotalPacketsReceived(), Is.EqualTo(3));
+            Assert.That(testLLPacketServer.GetPacketsReceivedFor(PacketType.ObjectName), Is.EqualTo(3));
+        }
+    }
+}

OpenSim/Region/ClientStack/Linden/UDP/Tests/MockScene.cs

@@ -0,0 +1,72 @@
+/*
+ * 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 OpenMetaverse;
+using OpenSim.Framework;
+using OpenSim.Region.Framework.Scenes;
+using GridRegion = OpenSim.Services.Interfaces.GridRegion;
+
+namespace OpenSim.Region.ClientStack.LindenUDP.Tests
+{
+    /// <summary>
+    /// Mock scene for unit tests
+    /// </summary>
+    public class MockScene : SceneBase
+    {
+        public int ObjectNameCallsReceived
+        {
+            get { return m_objectNameCallsReceived; }
+        }
+        protected int m_objectNameCallsReceived;
+        
+        public MockScene()
+        {
+            m_regInfo = new RegionInfo(1000, 1000, null, null);
+            m_regStatus = RegionStatus.Up;
+        }
+        
+        public override void Update() {}
+        public override void LoadWorldMap() {}
+        
+        public override void AddNewClient(IClientAPI client) 
+        {
+            client.OnObjectName += RecordObjectNameCall;
+        }
+        
+        public override void RemoveClient(UUID agentID) {}
+        public override void CloseAllAgents(uint circuitcode) {}
+        public override void OtherRegionUp(GridRegion otherRegion) {  }
+            
+        /// <summary>
+        /// Doesn't really matter what the call is - we're using this to test that a packet has actually been received
+        /// </summary>
+        protected void RecordObjectNameCall(IClientAPI remoteClient, uint localID, string message)
+        {
+            m_objectNameCallsReceived++;
+        }
+    }
+}

OpenSim/Region/ClientStack/Linden/UDP/Tests/PacketHandlerTests.cs

@@ -0,0 +1,106 @@
+/*
+ * 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 Nini.Config;
+using NUnit.Framework;
+using NUnit.Framework.SyntaxHelpers;
+using OpenMetaverse;
+using OpenMetaverse.Packets;
+using OpenSim.Framework;
+using OpenSim.Tests.Common.Mock;
+using OpenSim.Tests.Common;
+
+namespace OpenSim.Region.ClientStack.LindenUDP.Tests
+{
+    /// <summary>
+    /// Tests for the LL packet handler
+    /// </summary>
+    [TestFixture]
+    public class PacketHandlerTests
+    {
+        [Test]
+        /// <summary>
+        /// More a placeholder, really
+        /// </summary>
+        public void InPacketTest()
+        {
+            TestHelper.InMethod();
+
+            AgentCircuitData agent = new AgentCircuitData();
+            agent.AgentID = UUID.Random();
+            agent.firstname = "testfirstname";
+            agent.lastname = "testlastname";
+            agent.SessionID = UUID.Zero;
+            agent.SecureSessionID = UUID.Zero;
+            agent.circuitcode = 123;
+            agent.BaseFolder = UUID.Zero;
+            agent.InventoryFolder = UUID.Zero;
+            agent.startpos = Vector3.Zero;
+            agent.CapsPath = "http://wibble.com";
+            
+            TestLLUDPServer testLLUDPServer;
+            TestLLPacketServer testLLPacketServer;
+            AgentCircuitManager acm;
+            IScene scene = new MockScene();
+            SetupStack(scene, out testLLUDPServer, out testLLPacketServer, out acm);
+            
+            TestClient testClient = new TestClient(agent, scene);
+            
+            LLPacketHandler packetHandler 
+                = new LLPacketHandler(testClient, testLLPacketServer, new ClientStackUserSettings());
+            
+            packetHandler.InPacket(new AgentAnimationPacket());
+            LLQueItem receivedPacket = packetHandler.PacketQueue.Dequeue();
+            
+            Assert.That(receivedPacket, Is.Not.Null);
+            Assert.That(receivedPacket.Incoming, Is.True);
+            Assert.That(receivedPacket.Packet, Is.TypeOf(typeof(AgentAnimationPacket)));
+        }
+        
+        /// <summary>
+        /// Add a client for testing
+        /// </summary>
+        /// <param name="scene"></param>
+        /// <param name="testLLUDPServer"></param>
+        /// <param name="testPacketServer"></param>
+        /// <param name="acm">Agent circuit manager used in setting up the stack</param>
+        protected void SetupStack(
+            IScene scene, out TestLLUDPServer testLLUDPServer, out TestLLPacketServer testPacketServer, 
+            out AgentCircuitManager acm)
+        {
+            IConfigSource configSource = new IniConfigSource();
+            ClientStackUserSettings userSettings = new ClientStackUserSettings();
+            testLLUDPServer = new TestLLUDPServer();
+            acm = new AgentCircuitManager();
+                                    
+            uint port = 666;
+            testLLUDPServer.Initialise(null, ref port, 0, false, configSource, acm);
+            testPacketServer = new TestLLPacketServer(testLLUDPServer, userSettings);
+            testLLUDPServer.LocalScene = scene;
+        }
+    }
+}

OpenSim/Region/ClientStack/Linden/UDP/Tests/TestLLPacketServer.cs

@@ -0,0 +1,72 @@
+/*
+ * 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.Collections.Generic;
+using OpenMetaverse.Packets;
+
+namespace OpenSim.Region.ClientStack.LindenUDP.Tests
+{ 
+    public class TestLLPacketServer : LLPacketServer
+    {
+        /// <summary>
+        /// Record counts of packets received
+        /// </summary>
+        protected Dictionary<PacketType, int> m_packetsReceived = new Dictionary<PacketType, int>();
+        
+        public TestLLPacketServer(LLUDPServer networkHandler, ClientStackUserSettings userSettings)
+            : base(networkHandler, userSettings)
+        {}
+        
+        public override void InPacket(uint circuitCode, Packet packet)
+        {
+            base.InPacket(circuitCode, packet);
+            
+            if (m_packetsReceived.ContainsKey(packet.Type))
+                m_packetsReceived[packet.Type]++;
+            else
+                m_packetsReceived[packet.Type] = 1;
+        }
+        
+        public int GetTotalPacketsReceived()
+        {
+            int totalCount = 0;
+            
+            foreach (int count in m_packetsReceived.Values)
+                totalCount += count;
+            
+            return totalCount;
+        }
+        
+        public int GetPacketsReceivedFor(PacketType packetType)
+        {
+            if (m_packetsReceived.ContainsKey(packetType))
+                return m_packetsReceived[packetType];
+            else
+                return 0;
+        }
+    }
+}

OpenSim/Region/ClientStack/Linden/UDP/Tests/TestLLUDPServer.cs

@@ -0,0 +1,153 @@
+/*
+ * 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 OpenMetaverse.Packets;
+
+namespace OpenSim.Region.ClientStack.LindenUDP.Tests
+{
+    /// <summary>
+    /// This class enables synchronous testing of the LLUDPServer by allowing us to load our own data into the end 
+    /// receive event
+    /// </summary>
+    public class TestLLUDPServer : LLUDPServer
+    {
+        /// <summary>
+        /// The chunks of data to pass to the LLUDPServer when it calls EndReceive
+        /// </summary>
+        protected Queue<ChunkSenderTuple> m_chunksToLoad = new Queue<ChunkSenderTuple>();
+        
+        protected override void BeginReceive()
+        {
+            if (m_chunksToLoad.Count > 0 && m_chunksToLoad.Peek().BeginReceiveException)
+            {
+                ChunkSenderTuple tuple = m_chunksToLoad.Dequeue();
+                reusedEpSender = tuple.Sender;
+                throw new SocketException();
+            }
+        }
+        
+        protected override bool EndReceive(out int numBytes, IAsyncResult result, ref EndPoint epSender)
+        {
+            numBytes = 0;
+
+            //m_log.Debug("Queue size " + m_chunksToLoad.Count);
+            
+            if (m_chunksToLoad.Count <= 0)
+                return false;
+            
+            ChunkSenderTuple tuple = m_chunksToLoad.Dequeue();
+            RecvBuffer = tuple.Data;
+            numBytes   = tuple.Data.Length;
+            epSender   = tuple.Sender;
+            
+            return true;
+        }
+        
+        public override void SendPacketTo(byte[] buffer, int size, SocketFlags flags, uint circuitcode) 
+        {
+            // Don't do anything just yet
+        }
+        
+        /// <summary>
+        /// Signal that this chunk should throw an exception on Socket.BeginReceive()
+        /// </summary>
+        /// <param name="epSender"></param>
+        public void LoadReceiveWithBeginException(EndPoint epSender)
+        {
+            ChunkSenderTuple tuple = new ChunkSenderTuple(epSender);
+            tuple.BeginReceiveException = true;
+            m_chunksToLoad.Enqueue(tuple);
+        }
+        
+        /// <summary>
+        /// Load some data to be received by the LLUDPServer on the next receive call
+        /// </summary>
+        /// <param name="data"></param>
+        /// <param name="epSender"></param>
+        public void LoadReceive(byte[] data, EndPoint epSender)
+        {
+            m_chunksToLoad.Enqueue(new ChunkSenderTuple(data, epSender));
+        }
+        
+        /// <summary>
+        /// Load a packet to be received by the LLUDPServer on the next receive call
+        /// </summary>
+        /// <param name="packet"></param>
+        public void LoadReceive(Packet packet, EndPoint epSender)
+        {
+            LoadReceive(packet.ToBytes(), epSender);
+        }
+        
+        /// <summary>
+        /// Calls the protected asynchronous result method.  This fires out all data chunks currently queued for send
+        /// </summary>
+        /// <param name="result"></param>
+        public void ReceiveData(IAsyncResult result)
+        {
+            while (m_chunksToLoad.Count > 0)
+                OnReceivedData(result);
+        }
+        
+        /// <summary>
+        /// Has a circuit with the given code been established?
+        /// </summary>
+        /// <param name="circuitCode"></param>
+        /// <returns></returns>
+        public bool HasCircuit(uint circuitCode)
+        {
+            lock (clientCircuits_reverse)
+            {
+                return clientCircuits_reverse.ContainsKey(circuitCode);
+            }
+        }
+    }
+    
+    /// <summary>
+    /// Record the data and sender tuple
+    /// </summary>
+    public class ChunkSenderTuple
+    {
+        public byte[] Data;
+        public EndPoint Sender;
+        public bool BeginReceiveException;
+        
+        public ChunkSenderTuple(byte[] data, EndPoint sender)
+        {
+            Data = data;
+            Sender = sender;
+        }
+        
+        public ChunkSenderTuple(EndPoint sender)
+        {
+            Sender = sender;
+        }
+    }
+}

OpenSim/Region/ClientStack/Linden/UDP/ThrottleRates.cs

@@ -0,0 +1,111 @@
+/*
+ * 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 OpenSim.Framework;
+using Nini.Config;
+
+namespace OpenSim.Region.ClientStack.LindenUDP
+{
+    /// <summary>
+    /// Holds drip rates and maximum burst rates for throttling with hierarchical
+    /// token buckets. The maximum burst rates set here are hard limits and can
+    /// not be overridden by client requests
+    /// </summary>
+    public sealed class ThrottleRates
+    {
+        /// <summary>Drip rate for resent packets</summary>
+        public int Resend;
+        /// <summary>Drip rate for terrain packets</summary>
+        public int Land;
+        /// <summary>Drip rate for wind packets</summary>
+        public int Wind;
+        /// <summary>Drip rate for cloud packets</summary>
+        public int Cloud;
+        /// <summary>Drip rate for task packets</summary>
+        public int Task;
+        /// <summary>Drip rate for texture packets</summary>
+        public int Texture;
+        /// <summary>Drip rate for asset packets</summary>
+        public int Asset;
+
+        /// <summary>Drip rate for the parent token bucket</summary>
+        public int Total;
+
+        /// <summary>Flag used to enable adaptive throttles</summary>
+        public bool AdaptiveThrottlesEnabled;
+        
+        /// <summary>
+        /// Default constructor
+        /// </summary>
+        /// <param name="config">Config source to load defaults from</param>
+        public ThrottleRates(IConfigSource config)
+        {
+            try
+            {
+                IConfig throttleConfig = config.Configs["ClientStack.LindenUDP"];
+
+                Resend = throttleConfig.GetInt("resend_default", 6625);
+                Land = throttleConfig.GetInt("land_default", 9125);
+                Wind = throttleConfig.GetInt("wind_default", 1750);
+                Cloud = throttleConfig.GetInt("cloud_default", 1750);
+                Task = throttleConfig.GetInt("task_default", 18500);
+                Texture = throttleConfig.GetInt("texture_default", 18500);
+                Asset = throttleConfig.GetInt("asset_default", 10500);
+
+                Total = throttleConfig.GetInt("client_throttle_max_bps", 0);
+
+                AdaptiveThrottlesEnabled = throttleConfig.GetBoolean("enable_adaptive_throttles", false);
+            }
+            catch (Exception) { }
+        }
+
+        public int GetRate(ThrottleOutPacketType type)
+        {
+            switch (type)
+            {
+                case ThrottleOutPacketType.Resend:
+                    return Resend;
+                case ThrottleOutPacketType.Land:
+                    return Land;
+                case ThrottleOutPacketType.Wind:
+                    return Wind;
+                case ThrottleOutPacketType.Cloud:
+                    return Cloud;
+                case ThrottleOutPacketType.Task:
+                    return Task;
+                case ThrottleOutPacketType.Texture:
+                    return Texture;
+                case ThrottleOutPacketType.Asset:
+                    return Asset;
+                case ThrottleOutPacketType.Unknown:
+                default:
+                    return 0;
+            }
+        }
+    }
+}

OpenSim/Region/ClientStack/Linden/UDP/TokenBucket.cs

@@ -0,0 +1,393 @@
+/*
+ * 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;
+using System.Collections.Generic;
+using System.Reflection;
+using OpenSim.Framework;
+
+using log4net;
+
+namespace OpenSim.Region.ClientStack.LindenUDP
+{
+    /// <summary>
+    /// A hierarchical token bucket for bandwidth throttling. See
+    /// http://en.wikipedia.org/wiki/Token_bucket for more information
+    /// </summary>
+    public class TokenBucket
+    {
+        private static readonly ILog m_log = LogManager.GetLogger(MethodBase.GetCurrentMethod().DeclaringType);
+        private static Int32 m_counter = 0;
+        
+        private Int32 m_identifier;
+        
+        /// <summary>
+        /// Number of ticks (ms) per quantum, drip rate and max burst
+        /// are defined over this interval.
+        /// </summary>
+        protected const Int32 m_ticksPerQuantum = 1000;
+
+        /// <summary>
+        /// This is the number of quantums worth of packets that can
+        /// be accommodated during a burst
+        /// </summary>
+        protected const Double m_quantumsPerBurst = 1.5;
+                
+        /// <summary>
+        /// </summary>
+        protected const Int32 m_minimumDripRate = 1400;
+        
+        /// <summary>Time of the last drip, in system ticks</summary>
+        protected Int32 m_lastDrip;
+
+        /// <summary>
+        /// The number of bytes that can be sent at this moment. This is the
+        /// current number of tokens in the bucket
+        /// </summary>
+        protected Int64 m_tokenCount;
+
+        /// <summary>
+        /// Map of children buckets and their requested maximum burst rate
+        /// </summary>
+        protected Dictionary<TokenBucket,Int64> m_children = new Dictionary<TokenBucket,Int64>();
+        
+#region Properties
+
+        /// <summary>
+        /// The parent bucket of this bucket, or null if this bucket has no
+        /// parent. The parent bucket will limit the aggregate bandwidth of all
+        /// of its children buckets
+        /// </summary>
+        protected TokenBucket m_parent;
+        public TokenBucket Parent
+        {
+            get { return m_parent; }
+            set { m_parent = value; }
+        }
+
+        /// <summary>
+        /// Maximum burst rate in bytes per second. This is the maximum number
+        /// of tokens that can accumulate in the bucket at any one time. This 
+        /// also sets the total request for leaf nodes
+        /// </summary>
+        protected Int64 m_burstRate;
+        public Int64 RequestedBurstRate
+        {
+            get { return m_burstRate; }
+            set { m_burstRate = (value < 0 ? 0 : value); }
+        }
+
+        public Int64 BurstRate
+        {
+            get {
+                double rate = RequestedBurstRate * BurstRateModifier();
+                if (rate < m_minimumDripRate * m_quantumsPerBurst)
+                    rate = m_minimumDripRate * m_quantumsPerBurst;
+                
+                return (Int64) rate;
+            }
+        }
+               
+        /// <summary>
+        /// The speed limit of this bucket in bytes per second. This is the
+        /// number of tokens that are added to the bucket per quantum
+        /// </summary>
+        /// <remarks>Tokens are added to the bucket any time 
+        /// <seealso cref="RemoveTokens"/> is called, at the granularity of
+        /// the system tick interval (typically around 15-22ms)</remarks>
+        protected Int64 m_dripRate;
+        public virtual Int64 RequestedDripRate
+        {
+            get { return (m_dripRate == 0 ? m_totalDripRequest : m_dripRate); }
+            set {
+                m_dripRate = (value < 0 ? 0 : value);
+                m_burstRate = (Int64)((double)m_dripRate * m_quantumsPerBurst);
+                m_totalDripRequest = m_dripRate;
+                if (m_parent != null)
+                    m_parent.RegisterRequest(this,m_dripRate);
+            }
+        }
+
+        public virtual Int64 DripRate
+        {
+            get {
+                if (m_parent == null)
+                    return Math.Min(RequestedDripRate,TotalDripRequest);
+                
+                double rate = (double)RequestedDripRate * m_parent.DripRateModifier();
+                if (rate < m_minimumDripRate)
+                    rate = m_minimumDripRate;
+
+                return (Int64)rate;
+            }
+        }
+
+        /// <summary>
+        /// The current total of the requested maximum burst rates of 
+        /// this bucket's children buckets.
+        /// </summary>
+        protected Int64 m_totalDripRequest;
+        public Int64 TotalDripRequest 
+            {
+                get { return m_totalDripRequest; }
+                set { m_totalDripRequest = value; }
+            }
+        
+#endregion Properties
+
+#region Constructor
+
+        /// <summary>
+        /// Default constructor
+        /// </summary>
+        /// <param name="parent">Parent bucket if this is a child bucket, or
+        /// null if this is a root bucket</param>
+        /// <param name="maxBurst">Maximum size of the bucket in bytes, or
+        /// zero if this bucket has no maximum capacity</param>
+        /// <param name="dripRate">Rate that the bucket fills, in bytes per
+        /// second. If zero, the bucket always remains full</param>
+        public TokenBucket(TokenBucket parent, Int64 dripRate) 
+        {
+            m_identifier = m_counter++;
+
+            Parent = parent;
+            RequestedDripRate = dripRate;
+            // TotalDripRequest = dripRate; // this will be overwritten when a child node registers
+            // MaxBurst = (Int64)((double)dripRate * m_quantumsPerBurst);
+            m_lastDrip = Util.EnvironmentTickCount();
+        }
+
+#endregion Constructor
+
+        /// <summary>
+        /// Compute a modifier for the MaxBurst rate. This is 1.0, meaning
+        /// no modification if the requested bandwidth is less than the
+        /// max burst bandwidth all the way to the root of the throttle
+        /// hierarchy. However, if any of the parents is over-booked, then
+        /// the modifier will be less than 1.
+        /// </summary>
+        protected double DripRateModifier()
+        {
+            Int64 driprate = DripRate;
+            return driprate >= TotalDripRequest ? 1.0 : (double)driprate / (double)TotalDripRequest;
+        }
+
+        /// <summary>
+        /// </summary>
+        protected double BurstRateModifier()
+        {
+            // for now... burst rate is always m_quantumsPerBurst (constant)
+            // larger than drip rate so the ratio of burst requests is the
+            // same as the drip ratio
+            return DripRateModifier();
+        }
+
+        /// <summary>
+        /// Register drip rate requested by a child of this throttle. Pass the
+        /// changes up the hierarchy.
+        /// </summary>
+        public void RegisterRequest(TokenBucket child, Int64 request)
+        {
+            lock (m_children)
+            {
+                m_children[child] = request;
+                // m_totalDripRequest = m_children.Values.Sum();
+
+                m_totalDripRequest = 0;
+                foreach (KeyValuePair<TokenBucket, Int64> cref in m_children)
+                    m_totalDripRequest += cref.Value;
+            }
+            
+            // Pass the new values up to the parent
+            if (m_parent != null)
+                m_parent.RegisterRequest(this,Math.Min(RequestedDripRate, TotalDripRequest));
+        }
+
+        /// <summary>
+        /// Remove the rate requested by a child of this throttle. Pass the
+        /// changes up the hierarchy.
+        /// </summary>
+        public void UnregisterRequest(TokenBucket child)
+        {
+            lock (m_children)
+            {
+                m_children.Remove(child);
+                // m_totalDripRequest = m_children.Values.Sum();
+
+                m_totalDripRequest = 0;
+                foreach (KeyValuePair<TokenBucket, Int64> cref in m_children)
+                    m_totalDripRequest += cref.Value;
+            }
+            
+
+            // Pass the new values up to the parent
+            if (m_parent != null)
+                m_parent.RegisterRequest(this,Math.Min(RequestedDripRate, TotalDripRequest));
+        }
+        
+        /// <summary>
+        /// Remove a given number of tokens from the bucket
+        /// </summary>
+        /// <param name="amount">Number of tokens to remove from the bucket</param>
+        /// <returns>True if the requested number of tokens were removed from
+        /// the bucket, otherwise false</returns>
+        public bool RemoveTokens(Int64 amount)
+        {
+            // Deposit tokens for this interval
+            Drip();
+
+            // If we have enough tokens then remove them and return
+            if (m_tokenCount - amount >= 0)
+            {
+                // we don't have to remove from the parent, the drip rate is already
+                // reflective of the drip rate limits in the parent
+                m_tokenCount -= amount;
+                return true;
+            }
+
+            return false;
+        }
+
+        /// <summary>
+        /// Deposit tokens into the bucket from a child bucket that did
+        /// not use all of its available tokens
+        /// </summary>
+        protected void Deposit(Int64 count)
+        {
+            m_tokenCount += count;
+
+            // Deposit the overflow in the parent bucket, this is how we share
+            // unused bandwidth
+            Int64 burstrate = BurstRate;
+            if (m_tokenCount > burstrate)
+                m_tokenCount = burstrate;
+        }
+
+        /// <summary>
+        /// Add tokens to the bucket over time. The number of tokens added each
+        /// call depends on the length of time that has passed since the last 
+        /// call to Drip
+        /// </summary>
+        /// <returns>True if tokens were added to the bucket, otherwise false</returns>
+        protected void Drip()
+        {
+            // This should never happen... means we are a leaf node and were created
+            // with no drip rate...
+            if (DripRate == 0)
+            {
+                m_log.WarnFormat("[TOKENBUCKET] something odd is happening and drip rate is 0");
+                return;
+            }
+            
+            // Determine the interval over which we are adding tokens, never add
+            // more than a single quantum of tokens
+            Int32 deltaMS = Math.Min(Util.EnvironmentTickCountSubtract(m_lastDrip), m_ticksPerQuantum);
+            m_lastDrip = Util.EnvironmentTickCount();
+
+            // This can be 0 in the very unusual case that the timer wrapped
+            // It can be 0 if we try add tokens at a sub-tick rate
+            if (deltaMS <= 0)
+                return;
+
+            Deposit(deltaMS * DripRate / m_ticksPerQuantum);
+        }
+    }
+
+    public class AdaptiveTokenBucket : TokenBucket
+    {
+        private static readonly ILog m_log = LogManager.GetLogger(MethodBase.GetCurrentMethod().DeclaringType);
+
+        /// <summary>
+        /// The minimum rate for flow control. Minimum drip rate is one
+        /// packet per second. Open the throttle to 15 packets per second
+        /// or about 160kbps.
+        /// </summary>
+        protected const Int64 m_minimumFlow = m_minimumDripRate * 15;
+
+        // <summary>
+        // The maximum rate for flow control. Drip rate can never be
+        // greater than this.
+        // </summary>
+        protected Int64 m_maxDripRate = 0;
+        protected Int64 MaxDripRate
+        {
+            get { return (m_maxDripRate == 0 ? m_totalDripRequest : m_maxDripRate); }
+            set { m_maxDripRate = (value == 0 ? 0 : Math.Max(value,m_minimumFlow)); }
+        }
+        
+        private bool m_enabled = false;
+        
+        // <summary>
+        // 
+        // </summary>
+        public virtual Int64 AdjustedDripRate
+        {
+            get { return m_dripRate; }
+            set {
+                m_dripRate = OpenSim.Framework.Util.Clamp<Int64>(value,m_minimumFlow,MaxDripRate);
+                m_burstRate = (Int64)((double)m_dripRate * m_quantumsPerBurst);
+                if (m_parent != null)
+                    m_parent.RegisterRequest(this,m_dripRate);
+            }
+        }
+
+        // <summary>
+        // 
+        // </summary>
+        public AdaptiveTokenBucket(TokenBucket parent, Int64 maxDripRate, bool enabled) : base(parent,maxDripRate)
+        {
+            m_enabled = enabled;
+
+            if (m_enabled)
+            {
+                // m_log.DebugFormat("[TOKENBUCKET] Adaptive throttle enabled");
+                MaxDripRate = maxDripRate;
+                AdjustedDripRate = m_minimumFlow;
+            }
+        }
+                
+        // <summary>
+        // 
+        // </summary>
+        public void ExpirePackets(Int32 count)
+        {
+            // m_log.WarnFormat("[ADAPTIVEBUCKET] drop {0} by {1} expired packets",AdjustedDripRate,count);
+            if (m_enabled)
+                AdjustedDripRate = (Int64) (AdjustedDripRate / Math.Pow(2,count));
+        }
+
+        // <summary>
+        // 
+        // </summary>
+        public void AcknowledgePackets(Int32 count)
+        {
+            if (m_enabled)
+                AdjustedDripRate = AdjustedDripRate + count;
+        }
+    }
+}

OpenSim/Region/ClientStack/Linden/UDP/UnackedPacketCollection.cs

@@ -0,0 +1,219 @@
+/*
+ * 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.Threading;
+using OpenMetaverse;
+
+namespace OpenSim.Region.ClientStack.LindenUDP
+{
+    /// <summary>
+    /// Special collection that is optimized for tracking unacknowledged packets
+    /// </summary>
+    public sealed class UnackedPacketCollection
+    {
+        /// <summary>
+        /// Holds information about a pending acknowledgement
+        /// </summary>
+        private struct PendingAck
+        {
+            /// <summary>Sequence number of the packet to remove</summary>
+            public uint SequenceNumber;
+            /// <summary>Environment.TickCount value when the remove was queued.
+            /// This is used to update round-trip times for packets</summary>
+            public int RemoveTime;
+            /// <summary>Whether or not this acknowledgement was attached to a
+            /// resent packet. If so, round-trip time will not be calculated</summary>
+            public bool FromResend;
+
+            public PendingAck(uint sequenceNumber, int currentTime, bool fromResend)
+            {
+                SequenceNumber = sequenceNumber;
+                RemoveTime = currentTime;
+                FromResend = fromResend;
+            }
+        }
+
+        /// <summary>Holds the actual unacked packet data, sorted by sequence number</summary>
+        private Dictionary<uint, OutgoingPacket> m_packets = new Dictionary<uint, OutgoingPacket>();
+        /// <summary>Holds packets that need to be added to the unacknowledged list</summary>
+        private LocklessQueue<OutgoingPacket> m_pendingAdds = new LocklessQueue<OutgoingPacket>();
+        /// <summary>Holds information about pending acknowledgements</summary>
+        private LocklessQueue<PendingAck> m_pendingAcknowledgements = new LocklessQueue<PendingAck>();
+        /// <summary>Holds information about pending removals</summary>
+        private LocklessQueue<uint> m_pendingRemoves = new LocklessQueue<uint>();
+
+        /// <summary>
+        /// Add an unacked packet to the collection
+        /// </summary>
+        /// <param name="packet">Packet that is awaiting acknowledgement</param>
+        /// <returns>True if the packet was successfully added, false if the
+        /// packet already existed in the collection</returns>
+        /// <remarks>This does not immediately add the ACK to the collection,
+        /// it only queues it so it can be added in a thread-safe way later</remarks>
+        public void Add(OutgoingPacket packet)
+        {
+            m_pendingAdds.Enqueue(packet);
+            Interlocked.Add(ref packet.Client.UnackedBytes, packet.Buffer.DataLength);            
+        }
+
+        /// <summary>
+        /// Marks a packet as acknowledged
+        /// This method is used when an acknowledgement is received from the network for a previously
+        /// sent packet. Effects of removal this way are to update unacked byte count, adjust RTT
+        /// and increase throttle to the coresponding client.
+        /// </summary>
+        /// <param name="sequenceNumber">Sequence number of the packet to
+        /// acknowledge</param>
+        /// <param name="currentTime">Current value of Environment.TickCount</param>
+        /// <remarks>This does not immediately acknowledge the packet, it only
+        /// queues the ack so it can be handled in a thread-safe way later</remarks>
+        public void Acknowledge(uint sequenceNumber, int currentTime, bool fromResend)
+        {
+            m_pendingAcknowledgements.Enqueue(new PendingAck(sequenceNumber, currentTime, fromResend));
+        }
+
+        /// <summary>
+        /// Marks a packet as no longer needing acknowledgement without a received acknowledgement.
+        /// This method is called when a packet expires and we no longer need an acknowledgement.
+        /// When some reliable packet types expire, they are handled in a way other than simply 
+        /// resending them. The only effect of removal this way is to update unacked byte count.
+        /// </summary>
+        /// <param name="sequenceNumber">Sequence number of the packet to
+        /// acknowledge</param>
+        /// <remarks>The does not immediately remove the packet, it only queues the removal
+        /// so it can be handled in a thread safe way later</remarks>
+        public void Remove(uint sequenceNumber)
+        {
+            m_pendingRemoves.Enqueue(sequenceNumber);
+        }
+
+        /// <summary>
+        /// Returns a list of all of the packets with a TickCount older than
+        /// the specified timeout
+        /// </summary>
+        /// <param name="timeoutMS">Number of ticks (milliseconds) before a
+        /// packet is considered expired</param>
+        /// <returns>A list of all expired packets according to the given
+        /// expiration timeout</returns>
+        /// <remarks>This function is not thread safe, and cannot be called
+        /// multiple times concurrently</remarks>
+        public List<OutgoingPacket> GetExpiredPackets(int timeoutMS)
+        {
+            ProcessQueues();
+
+            List<OutgoingPacket> expiredPackets = null;
+
+            if (m_packets.Count > 0)
+            {
+                int now = Environment.TickCount & Int32.MaxValue;
+
+                foreach (OutgoingPacket packet in m_packets.Values)
+                {
+                    // TickCount of zero means a packet is in the resend queue 
+                    // but hasn't actually been sent over the wire yet
+                    if (packet.TickCount == 0)
+                        continue;
+
+                    if (now - packet.TickCount >= timeoutMS)
+                    {
+                        if (expiredPackets == null)
+                            expiredPackets = new List<OutgoingPacket>();
+
+                        // The TickCount will be set to the current time when the packet
+                        // is actually sent out again
+                        packet.TickCount = 0;
+
+                        // As with other network applications, assume that an expired packet is
+                        // an indication of some network problem, slow transmission
+                        packet.Client.FlowThrottle.ExpirePackets(1);
+                        
+                        expiredPackets.Add(packet);
+                    }
+                }
+            }
+
+            return expiredPackets;
+        }
+
+        private void ProcessQueues()
+        {
+            // Process all the pending adds
+            OutgoingPacket pendingAdd;
+            while (m_pendingAdds.TryDequeue(out pendingAdd))
+                if (pendingAdd != null)
+                    m_packets[pendingAdd.SequenceNumber] = pendingAdd;
+            
+            // Process all the pending removes, including updating statistics and round-trip times
+            PendingAck pendingAcknowledgement;
+            while (m_pendingAcknowledgements.TryDequeue(out pendingAcknowledgement))
+            {
+                OutgoingPacket ackedPacket;
+                if (m_packets.TryGetValue(pendingAcknowledgement.SequenceNumber, out ackedPacket))
+                {
+                    if (ackedPacket != null)
+                    {
+                        m_packets.Remove(pendingAcknowledgement.SequenceNumber);
+
+                        // As with other network applications, assume that an acknowledged packet is an
+                        // indication that the network can handle a little more load, speed up the transmission
+                        ackedPacket.Client.FlowThrottle.AcknowledgePackets(ackedPacket.Buffer.DataLength);
+
+                        // Update stats
+                        Interlocked.Add(ref ackedPacket.Client.UnackedBytes, -ackedPacket.Buffer.DataLength);
+
+                        if (!pendingAcknowledgement.FromResend)
+                        {
+                            // Calculate the round-trip time for this packet and its ACK
+                            int rtt = pendingAcknowledgement.RemoveTime - ackedPacket.TickCount;
+                            if (rtt > 0)
+                                ackedPacket.Client.UpdateRoundTrip(rtt);
+                        }
+                    }
+                }
+            }
+
+            uint pendingRemove;
+            while(m_pendingRemoves.TryDequeue(out pendingRemove))
+            {
+                OutgoingPacket removedPacket;
+                if (m_packets.TryGetValue(pendingRemove, out removedPacket))
+                {
+                    if (removedPacket != null)
+                    {
+                        m_packets.Remove(pendingRemove);
+
+                        // Update stats
+                        Interlocked.Add(ref removedPacket.Client.UnackedBytes, -removedPacket.Buffer.DataLength);
+                    }
+                }
+            }
+        }
+    }
+}