starting phase 2 of the OpenSim.Region.Environment commit: relocating

OpenSim.Region.Environment.Modules.Agent en bloc to OpenSim.Region.CoreModules

3 files changed, 652 insertions, 0 deletions

diff --git a/OpenSim/Region/CoreModules/Agent/TextureDownload/TextureDownloadModule.cs b/OpenSim/Region/CoreModules/Agent/TextureDownload/TextureDownloadModule.cs
new file mode 100644
index 0000000..107855d
--- /dev/null
+++ b/OpenSim/Region/CoreModules/Agent/TextureDownload/TextureDownloadModule.cs
@@ -0,0 +1,295 @@
+/*
+ * 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 OpenSim 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.Threading;
+using OpenMetaverse;
+using Nini.Config;
+using OpenSim.Framework;
+using OpenSim.Region.Framework.Interfaces;
+using OpenSim.Region.Framework.Scenes;
+using OpenSim.Framework.Communications.Cache;
+using BlockingQueue = OpenSim.Framework.BlockingQueue<OpenSim.Region.Framework.Interfaces.ITextureSender>;
+
+namespace OpenSim.Region.CoreModules.Agent.TextureDownload
+{
+    public class TextureDownloadModule : IRegionModule
+    {
+        private static readonly log4net.ILog m_log
+            = log4net.LogManager.GetLogger(System.Reflection.MethodBase.GetCurrentMethod().DeclaringType);
+
+        /// <summary>
+        /// There is one queue for all textures waiting to be sent, regardless of the requesting user.
+        /// </summary>
+        private readonly OpenSim.Framework.BlockingQueue<ITextureSender> m_queueSenders
+            = new OpenSim.Framework.BlockingQueue<ITextureSender>();
+
+        /// <summary>
+        /// Each user has their own texture download service.
+        /// </summary>
+        private readonly Dictionary<UUID, UserTextureDownloadService> m_userTextureServices =
+            new Dictionary<UUID, UserTextureDownloadService>();
+
+        private Scene m_scene;
+        private List<Scene> m_scenes = new List<Scene>();
+
+        private Thread m_thread;
+
+        public TextureDownloadModule()
+        {
+        }
+
+        #region IRegionModule Members
+
+        public void Initialise(Scene scene, IConfigSource config)
+        {
+            if (m_scene == null)
+            {
+                //Console.WriteLine("Creating Texture download module");
+                m_scene = scene;
+                m_thread = new Thread(new ThreadStart(ProcessTextureSenders));
+                m_thread.Name = "ProcessTextureSenderThread";
+                m_thread.IsBackground = true;
+                m_thread.Start();
+                ThreadTracker.Add(m_thread);
+            }
+
+            if (!m_scenes.Contains(scene))
+            {
+                m_scenes.Add(scene);
+                m_scene = scene;
+                m_scene.EventManager.OnNewClient += NewClient;
+                m_scene.EventManager.OnRemovePresence += EventManager_OnRemovePresence;
+            }
+        }
+
+        public void PostInitialise()
+        {
+        }
+
+        public void Close()
+        {
+        }
+
+        public string Name
+        {
+            get { return "TextureDownloadModule"; }
+        }
+
+        public bool IsSharedModule
+        {
+            get { return false; }
+        }
+
+        #endregion
+
+        /// <summary>
+        /// Cleanup the texture service related objects for the removed presence.
+        /// </summary>
+        /// <param name="agentId"> </param>
+        private void EventManager_OnRemovePresence(UUID agentId)
+        {
+            UserTextureDownloadService textureService;
+
+            lock (m_userTextureServices)
+            {
+                if (m_userTextureServices.TryGetValue(agentId, out textureService))
+                {
+                    textureService.Close();
+                    //m_log.DebugFormat("[TEXTURE MODULE]: Removing UserTextureServices from {0}", m_scene.RegionInfo.RegionName);
+                    m_userTextureServices.Remove(agentId);
+                }
+            }
+        }
+
+        public void NewClient(IClientAPI client)
+        {
+            UserTextureDownloadService textureService;
+
+            lock (m_userTextureServices)
+            {
+                if (m_userTextureServices.TryGetValue(client.AgentId, out textureService))
+                {
+                    textureService.Close();
+                    //m_log.DebugFormat("[TEXTURE MODULE]: Removing outdated UserTextureServices from {0}", m_scene.RegionInfo.RegionName);
+                    m_userTextureServices.Remove(client.AgentId);
+                }
+                m_userTextureServices.Add(client.AgentId, new UserTextureDownloadService(client, m_scene, m_queueSenders));
+            }
+
+            client.OnRequestTexture += TextureRequest;
+        }
+
+        /// I'm commenting this out, and replacing it with the implementation below, which
+        /// may return a null value. This is necessary for avoiding race conditions 
+        /// recreating UserTextureServices for clients that have just been closed.
+        /// That behavior of always returning a UserTextureServices was causing the
+        /// A-B-A problem (mantis #2855).
+        /// 
+        ///// <summary>
+        ///// Does this user have a registered texture download service?
+        ///// </summary>
+        ///// <param name="userID"></param>
+        ///// <param name="textureService"></param>
+        ///// <returns>Always returns true, since a service is created if one does not already exist</returns>
+        //private bool TryGetUserTextureService(
+        //    IClientAPI client, out UserTextureDownloadService textureService)
+        //{
+        //    lock (m_userTextureServices)
+        //    {
+        //        if (m_userTextureServices.TryGetValue(client.AgentId, out textureService))
+        //        {
+        //            //m_log.DebugFormat("[TEXTURE MODULE]: Found existing UserTextureServices in ", m_scene.RegionInfo.RegionName);
+        //            return true;
+        //        }
+
+        //        m_log.DebugFormat("[TEXTURE MODULE]: Creating new UserTextureServices in ", m_scene.RegionInfo.RegionName);
+        //        textureService = new UserTextureDownloadService(client, m_scene, m_queueSenders);
+        //        m_userTextureServices.Add(client.AgentId, textureService);
+
+        //        return true;
+        //    }
+        //}
+
+        /// <summary>
+        /// Does this user have a registered texture download service?
+        /// </summary>
+        /// <param name="userID"></param>
+        /// <param name="textureService"></param>
+        /// <returns>A UserTextureDownloadService or null in the output parameter, and true or false accordingly.</returns>
+        private bool TryGetUserTextureService(IClientAPI client, out UserTextureDownloadService textureService)
+        {
+            lock (m_userTextureServices)
+            {
+                if (m_userTextureServices.TryGetValue(client.AgentId, out textureService))
+                {
+                    //m_log.DebugFormat("[TEXTURE MODULE]: Found existing UserTextureServices in ", m_scene.RegionInfo.RegionName);
+                    return true;
+                }
+
+                textureService = null;
+                return false;
+            }
+        }
+
+        /// <summary>
+        /// Start the process of requesting a given texture.
+        /// </summary>
+        /// <param name="sender"> </param>
+        /// <param name="e"></param>
+        public void TextureRequest(Object sender, TextureRequestArgs e)
+        {
+            IClientAPI client = (IClientAPI)sender;
+
+            if (e.Priority == 1016001f) // Preview
+            {
+                if (client.Scene is Scene)
+                {
+                    Scene scene = (Scene)client.Scene;
+
+                    CachedUserInfo profile = scene.CommsManager.UserProfileCacheService.GetUserDetails(client.AgentId);
+                    if (profile == null) // Deny unknown user
+                        return;
+
+                    if (profile.RootFolder == null) // Deny no inventory
+                        return;
+
+                    if (profile.UserProfile.GodLevel < 200 && profile.RootFolder.FindAsset(e.RequestedAssetID) == null) // Deny if not owned
+                        return;
+
+                    m_log.Debug("Texture preview");
+                }
+            }
+
+            UserTextureDownloadService textureService;
+
+            if (TryGetUserTextureService(client, out textureService))
+            {
+                textureService.HandleTextureRequest(e);
+            }
+        }
+
+        /// <summary>
+        /// Entry point for the thread dedicated to processing the texture queue.
+        /// </summary>
+        public void ProcessTextureSenders()
+        {
+            ITextureSender sender = null;
+
+            try
+            {
+                while (true)
+                {
+                    sender = m_queueSenders.Dequeue();
+
+                    if (sender.Cancel)
+                    {
+                        TextureSent(sender);
+
+                        sender.Cancel = false;
+                    }
+                    else
+                    {
+                        bool finished = sender.SendTexturePacket();
+                        if (finished)
+                        {
+                            TextureSent(sender);
+                        }
+                        else
+                        {
+                            m_queueSenders.Enqueue(sender);
+                        }
+                    }
+
+                    // Make sure that any sender we currently have can get garbage collected
+                    sender = null;
+
+                    //m_log.InfoFormat("[TEXTURE] Texture sender queue size: {0}", m_queueSenders.Count());
+                }
+            }
+            catch (Exception e)
+            {
+                // TODO: Let users in the sim and those entering it and possibly an external watchdog know what has happened
+                m_log.ErrorFormat(
+                    "[TEXTURE]: Texture send thread terminating with exception.  PLEASE REBOOT YOUR SIM - TEXTURES WILL NOT BE AVAILABLE UNTIL YOU DO.  Exception is {0}",
+                    e);
+            }
+        }
+
+        /// <summary>
+        /// Called when the texture has finished sending.
+        /// </summary>
+        /// <param name="sender"></param>
+        private void TextureSent(ITextureSender sender)
+        {
+            sender.Sending = false;
+            //m_log.DebugFormat("[TEXTURE]: Removing download stat for {0}", sender.assetID);
+            m_scene.AddPendingDownloads(-1);
+        }
+    }
+}
diff --git a/OpenSim/Region/CoreModules/Agent/TextureDownload/TextureNotFoundSender.cs b/OpenSim/Region/CoreModules/Agent/TextureDownload/TextureNotFoundSender.cs
new file mode 100644
index 0000000..7309282
--- /dev/null
+++ b/OpenSim/Region/CoreModules/Agent/TextureDownload/TextureNotFoundSender.cs
@@ -0,0 +1,90 @@
+/*
+ * 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 OpenSim 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.Reflection;
+using log4net;
+using OpenMetaverse;
+using OpenMetaverse.Packets;
+using OpenSim.Framework;
+using OpenSim.Region.Framework.Interfaces;
+
+namespace OpenSim.Region.CoreModules.Agent.TextureDownload
+{
+    /// <summary>
+    /// Sends a 'texture not found' packet back to the client
+    /// </summary>
+    public class TextureNotFoundSender : ITextureSender
+    {
+        //        private static readonly log4net.ILog m_log
+        //            = log4net.LogManager.GetLogger(System.Reflection.MethodBase.GetCurrentMethod().DeclaringType);
+
+        //        private IClientAPI m_client;
+        //        private UUID m_textureId;
+
+        public TextureNotFoundSender(IClientAPI client, UUID textureID)
+        {
+            //m_client = client;
+            //m_textureId = textureID;
+        }
+
+        #region ITextureSender Members
+
+        public bool Sending
+        {
+            get { return false; }
+            set { }
+        }
+
+        public bool Cancel
+        {
+            get { return false; }
+            set { }
+        }
+
+        // See ITextureSender
+        public void UpdateRequest(int discardLevel, uint packetNumber)
+        {
+            // No need to implement since priority changes don't affect this operation
+        }
+
+        // See ITextureSender
+        public bool SendTexturePacket()
+        {
+            //            m_log.DebugFormat(
+            //                "[TEXTURE NOT FOUND SENDER]: Informing the client that texture {0} cannot be found",
+            //                m_textureId);
+
+            // XXX Temporarily disabling as this appears to be causing client crashes on at least
+            // 1.19.0(5) of the Linden Second Life client.
+            //            m_client.SendImageNotFound(m_textureId);
+
+            return true;
+        }
+
+        #endregion
+    }
+}
diff --git a/OpenSim/Region/CoreModules/Agent/TextureDownload/UserTextureDownloadService.cs b/OpenSim/Region/CoreModules/Agent/TextureDownload/UserTextureDownloadService.cs
new file mode 100644
index 0000000..675bb0f
--- /dev/null
+++ b/OpenSim/Region/CoreModules/Agent/TextureDownload/UserTextureDownloadService.cs
@@ -0,0 +1,267 @@
+/*
+ * 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 OpenSim 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 System.Reflection;
+using OpenMetaverse;
+using log4net;
+using OpenSim.Framework;
+using OpenSim.Framework.Communications.Limit;
+using OpenSim.Framework.Statistics;
+using OpenSim.Region.Framework.Interfaces;
+using OpenSim.Region.Framework.Scenes;
+
+namespace OpenSim.Region.CoreModules.Agent.TextureDownload
+{
+    /// <summary>
+    /// This module sets up texture senders in response to client texture requests, and places them on a
+    /// processing queue once those senders have the appropriate data (i.e. a texture retrieved from the
+    /// asset cache).
+    /// </summary>
+    public class UserTextureDownloadService
+    {
+        private static readonly ILog m_log
+            = LogManager.GetLogger(MethodBase.GetCurrentMethod().DeclaringType);
+
+        /// <summary>
+        /// True if the service has been closed, probably because a user with texture requests still queued
+        /// logged out.
+        /// </summary>
+        private bool closed;
+
+        /// <summary>
+        /// We will allow the client to request the same texture n times before dropping further requests
+        ///
+        /// This number includes repeated requests for the same texture at different resolutions (which we don't
+        /// currently handle properly as far as I know).  However, this situation should be handled in a more
+        /// sophisticated way.
+        /// </summary>
+        private static readonly int MAX_ALLOWED_TEXTURE_REQUESTS = 5;
+
+        /// <summary>
+        /// XXX Also going to limit requests for found textures.
+        /// </summary>
+        private readonly IRequestLimitStrategy<UUID> foundTextureLimitStrategy
+            = new RepeatLimitStrategy<UUID>(MAX_ALLOWED_TEXTURE_REQUESTS);
+
+        private readonly IClientAPI m_client;
+        private readonly Scene m_scene;
+
+        /// <summary>
+        /// Texture Senders are placed in this queue once they have received their texture from the asset
+        /// cache.  Another module actually invokes the send.
+        /// </summary>
+        private readonly OpenSim.Framework.BlockingQueue<ITextureSender> m_sharedSendersQueue;
+
+        /// <summary>
+        /// Holds texture senders before they have received the appropriate texture from the asset cache.
+        /// </summary>
+        private readonly Dictionary<UUID, TextureSender.TextureSender> m_textureSenders = new Dictionary<UUID, TextureSender.TextureSender>();
+
+        /// <summary>
+        /// We're going to limit requests for the same missing texture.
+        /// XXX This is really a temporary solution to deal with the situation where a client continually requests
+        /// the same missing textures
+        /// </summary>
+        private readonly IRequestLimitStrategy<UUID> missingTextureLimitStrategy
+            = new RepeatLimitStrategy<UUID>(MAX_ALLOWED_TEXTURE_REQUESTS);
+
+        public UserTextureDownloadService(
+            IClientAPI client, Scene scene, OpenSim.Framework.BlockingQueue<ITextureSender> sharedQueue)
+        {
+            m_client = client;
+            m_scene = scene;
+            m_sharedSendersQueue = sharedQueue;
+        }
+
+        /// <summary>
+        /// Handle a texture request.  This involves creating a texture sender and placing it on the
+        /// previously passed in shared queue.
+        /// </summary>
+        /// <param name="e"></param>
+        public void HandleTextureRequest(TextureRequestArgs e)
+        {
+            TextureSender.TextureSender textureSender;
+
+            //TODO: should be working out the data size/ number of packets to be sent for each discard level
+            if ((e.DiscardLevel >= 0) || (e.Priority != 0))
+            {
+                lock (m_textureSenders)
+                {
+                    if (m_textureSenders.TryGetValue(e.RequestedAssetID, out textureSender))
+                    {
+                        // If we've received new non UUID information for this request and it hasn't dispatched
+                        // yet, then update the request accordingly.
+                        textureSender.UpdateRequest(e.DiscardLevel, e.PacketNumber);
+                    }
+                    else
+                    {
+                        //                        m_log.DebugFormat("[TEXTURE]: Received a request for texture {0}", e.RequestedAssetID);
+
+                        if (!foundTextureLimitStrategy.AllowRequest(e.RequestedAssetID))
+                        {
+                            //                            m_log.DebugFormat(
+                            //                                "[TEXTURE]: Refusing request for {0} from client {1}",
+                            //                                e.RequestedAssetID, m_client.AgentId);
+
+                            return;
+                        }
+                        else if (!missingTextureLimitStrategy.AllowRequest(e.RequestedAssetID))
+                        {
+                            if (missingTextureLimitStrategy.IsFirstRefusal(e.RequestedAssetID))
+                            {
+                                if (StatsManager.SimExtraStats != null)
+                                    StatsManager.SimExtraStats.AddBlockedMissingTextureRequest();
+
+                                // Commenting out this message for now as it causes too much noise with other
+                                // debug messages.
+                                //                                m_log.DebugFormat(
+                                //                                    "[TEXTURE]: Dropping requests for notified missing texture {0} for client {1} since we have received more than {2} requests",
+                                //                                    e.RequestedAssetID, m_client.AgentId, MAX_ALLOWED_TEXTURE_REQUESTS);
+                            }
+
+                            return;
+                        }
+
+                        m_scene.AddPendingDownloads(1);
+
+                        TextureSender.TextureSender requestHandler = new TextureSender.TextureSender(m_client, e.DiscardLevel, e.PacketNumber);
+                        m_textureSenders.Add(e.RequestedAssetID, requestHandler);
+
+                        m_scene.AssetCache.GetAsset(e.RequestedAssetID, TextureCallback, true);
+                    }
+                }
+            }
+            else
+            {
+                lock (m_textureSenders)
+                {
+                    if (m_textureSenders.TryGetValue(e.RequestedAssetID, out textureSender))
+                    {
+                        textureSender.Cancel = true;
+                    }
+                }
+            }
+        }
+
+        /// <summary>
+        /// The callback for the asset cache when a texture has been retrieved.  This method queues the
+        /// texture sender for processing.
+        /// </summary>
+        /// <param name="textureID"></param>
+        /// <param name="texture"></param>
+        public void TextureCallback(UUID textureID, AssetBase texture)
+        {
+            //m_log.DebugFormat("[USER TEXTURE DOWNLOAD SERVICE]: Calling TextureCallback with {0}, texture == null is {1}", textureID, (texture == null ? true : false));
+
+            // There may still be texture requests pending for a logged out client
+            if (closed)
+                return;
+
+            lock (m_textureSenders)
+            {
+                TextureSender.TextureSender textureSender;
+                if (m_textureSenders.TryGetValue(textureID, out textureSender))
+                {
+                    // XXX It may be perfectly valid for a texture to have no data...  but if we pass
+                    // this on to the TextureSender it will blow up, so just discard for now.
+                    // Needs investigation.
+                    if (texture == null || texture.Data == null)
+                    {
+                        if (!missingTextureLimitStrategy.IsMonitoringRequests(textureID))
+                        {
+                            missingTextureLimitStrategy.MonitorRequests(textureID);
+
+                            //                            m_log.DebugFormat(
+                            //                                "[TEXTURE]: Queueing first TextureNotFoundSender for {0}, client {1}",
+                            //                                textureID, m_client.AgentId);
+                        }
+
+                        ITextureSender textureNotFoundSender = new TextureNotFoundSender(m_client, textureID);
+                        EnqueueTextureSender(textureNotFoundSender);
+                    }
+                    else
+                    {
+                        if (!textureSender.ImageLoaded)
+                        {
+                            textureSender.TextureReceived(texture);
+                            EnqueueTextureSender(textureSender);
+
+                            foundTextureLimitStrategy.MonitorRequests(textureID);
+                        }
+                    }
+
+                    //m_log.InfoFormat("[TEXTURE] Removing texture sender with uuid {0}", textureID);
+                    m_textureSenders.Remove(textureID);
+                    //m_log.InfoFormat("[TEXTURE] Current texture senders in dictionary: {0}", m_textureSenders.Count);
+                }
+                else
+                {
+                    m_log.WarnFormat(
+                        "[TEXTURE]: Got a texture uuid {0} with no sender object to handle it, this shouldn't happen",
+                        textureID);
+                }
+            }
+        }
+
+        /// <summary>
+        /// Place a ready texture sender on the processing queue.
+        /// </summary>
+        /// <param name="textureSender"></param>
+        private void EnqueueTextureSender(ITextureSender textureSender)
+        {
+            textureSender.Cancel = false;
+            textureSender.Sending = true;
+
+            if (!m_sharedSendersQueue.Contains(textureSender))
+            {
+                m_sharedSendersQueue.Enqueue(textureSender);
+            }
+        }
+
+        /// <summary>
+        /// Close this module.
+        /// </summary>
+        internal void Close()
+        {
+            closed = true;
+
+            lock (m_textureSenders)
+            {
+                foreach (TextureSender.TextureSender textureSender in m_textureSenders.Values)
+                {
+                    textureSender.Cancel = true;
+                }
+
+                m_textureSenders.Clear();
+            }
+
+            // XXX: It might be possible to also remove pending texture requests from the asset cache queues,
+            // though this might also be more trouble than it's worth.
+        }
+    }
+}