* Change Util.FireAndForget to use ThreadPool.UnsafeQueueUserWorkItem(). This avoids .NET remoting and a managed->unmanaged->managed jump. Overall, a night and day performance difference

* Initialize the LLClientView prim full update queue to the number of prims in the scene for a big performance boost
* Reordered some comparisons on hot code paths for a minor speed boost
* Removed an unnecessary call to the expensive DateTime.Now function (if you *have* to get the current time as opposed to Environment.TickCount, always use DateTime.UtcNow)
* Don't fire the queue empty callback for the Resend category
* Run the outgoing packet handler thread loop for each client synchronously. It seems like more time was being spent doing the execution asynchronously, and it made deadlocks very difficult to track down
* Rewrote some expensive math in LandObject.cs
* Optimized EntityManager to only lock on operations that need locking, and use TryGetValue() where possible
* Only update the attachment database when an object is attached or detached
* Other small misc. performance improvements

4 files changed, 62 insertions, 56 deletions

diff --git a/OpenSim/Region/ClientStack/LindenUDP/LLClientView.cs b/OpenSim/Region/ClientStack/LindenUDP/LLClientView.cs
index 1c463ea..b027882 100644
--- a/OpenSim/Region/ClientStack/LindenUDP/LLClientView.cs
+++ b/OpenSim/Region/ClientStack/LindenUDP/LLClientView.cs
@@ -321,12 +321,9 @@ namespace OpenSim.Region.ClientStack.LindenUDP
         private readonly IGroupsModule m_GroupsModule;
 
         private int m_cachedTextureSerial;
-        private PriorityQueue<double, ImprovedTerseObjectUpdatePacket.ObjectDataBlock> m_avatarTerseUpdates =
-            new PriorityQueue<double, ImprovedTerseObjectUpdatePacket.ObjectDataBlock>();
-        private PriorityQueue<double, ImprovedTerseObjectUpdatePacket.ObjectDataBlock> m_primTerseUpdates =
-            new PriorityQueue<double, ImprovedTerseObjectUpdatePacket.ObjectDataBlock>();
-        private PriorityQueue<double, ObjectUpdatePacket.ObjectDataBlock> m_primFullUpdates =
-            new PriorityQueue<double, ObjectUpdatePacket.ObjectDataBlock>();
+        private PriorityQueue<double, ImprovedTerseObjectUpdatePacket.ObjectDataBlock> m_avatarTerseUpdates;
+        private PriorityQueue<double, ImprovedTerseObjectUpdatePacket.ObjectDataBlock> m_primTerseUpdates;
+        private PriorityQueue<double, ObjectUpdatePacket.ObjectDataBlock> m_primFullUpdates;
         private int m_moneyBalance;
         private int m_animationSequenceNumber = 1;
         private bool m_SendLogoutPacketWhenClosing = true;
@@ -335,7 +332,7 @@ namespace OpenSim.Region.ClientStack.LindenUDP
 
         protected Dictionary<PacketType, PacketMethod> m_packetHandlers = new Dictionary<PacketType, PacketMethod>();
         protected Dictionary<string, GenericMessage> m_genericPacketHandlers = new Dictionary<string, GenericMessage>(); //PauPaw:Local Generic Message handlers
-        protected IScene m_scene;
+        protected Scene m_scene;
         protected LLImageManager m_imageManager;
         protected string m_firstName;
         protected string m_lastName;
@@ -408,16 +405,21 @@ namespace OpenSim.Region.ClientStack.LindenUDP
         /// <summary>
         /// Constructor
         /// </summary>
-        public LLClientView(EndPoint remoteEP, IScene scene, LLUDPServer udpServer, LLUDPClient udpClient, AuthenticateResponse sessionInfo,
+        public LLClientView(EndPoint remoteEP, Scene scene, LLUDPServer udpServer, LLUDPClient udpClient, AuthenticateResponse sessionInfo,
             UUID agentId, UUID sessionId, uint circuitCode)
         {
             RegisterInterface<IClientIM>(this);
             RegisterInterface<IClientChat>(this);
             RegisterInterface<IClientIPEndpoint>(this);
-            
+
             InitDefaultAnimations();
 
             m_scene = scene;
+
+            m_avatarTerseUpdates = new PriorityQueue<double, ImprovedTerseObjectUpdatePacket.ObjectDataBlock>();
+            m_primTerseUpdates = new PriorityQueue<double, ImprovedTerseObjectUpdatePacket.ObjectDataBlock>();
+            m_primFullUpdates = new PriorityQueue<double, ObjectUpdatePacket.ObjectDataBlock>(m_scene.Entities.Count);
+
             m_assetService = m_scene.RequestModuleInterface<IAssetService>();
             m_hyperAssets = m_scene.RequestModuleInterface<IHyperAssetService>();
             m_GroupsModule = scene.RequestModuleInterface<IGroupsModule>();
@@ -3288,10 +3290,7 @@ namespace OpenSim.Region.ClientStack.LindenUDP
             }
 
             Quaternion rotation = data.Rotation;
-
-            if (rotation.X == rotation.Y &&
-                rotation.Y == rotation.Z &&
-                rotation.Z == rotation.W && rotation.W == 0.0f)
+            if (rotation.W == 0.0f && rotation.X == 0.0f && rotation.Y == 0.0f && rotation.Z == 0.0f)
                 rotation = Quaternion.Identity;
 
             ImprovedTerseObjectUpdatePacket.ObjectDataBlock terseBlock = CreateImprovedTerseBlock(data);
@@ -3377,15 +3376,14 @@ namespace OpenSim.Region.ClientStack.LindenUDP
             }
 
             Quaternion rotation = data.rotation;
+            if (rotation.W == 0.0f && rotation.X == 0.0f && rotation.Y == 0.0f && rotation.Z == 0.0f)
+                rotation = Quaternion.Identity;
 
             if (data.AttachPoint > 30 && data.ownerID != AgentId) // Someone else's HUD
                 return;
-            if (data.primShape.PCode == 9 && data.primShape.State != 0 && data.parentID == 0)
+            if (data.primShape.State != 0 && data.parentID == 0 && data.primShape.PCode == 9)
                 return;
 
-            if (rotation.X == rotation.Y && rotation.Y == rotation.Z && rotation.Z == rotation.W && rotation.W == 0.0f)
-                rotation = Quaternion.Identity;
-
             ObjectUpdatePacket.ObjectDataBlock objectData = CreatePrimUpdateBlock(data);
 
             lock (m_primFullUpdates.SyncRoot)
@@ -3397,7 +3395,6 @@ namespace OpenSim.Region.ClientStack.LindenUDP
             ObjectUpdatePacket outPacket = (ObjectUpdatePacket)PacketPool.Instance.GetPacket(PacketType.ObjectUpdate);
             outPacket.Header.Zerocoded = true;
 
-            //outPacket.RegionData = new ObjectUpdatePacket.RegionDataBlock();
             outPacket.RegionData.RegionHandle = Scene.RegionInfo.RegionHandle;
             outPacket.RegionData.TimeDilation = (ushort)(Scene.TimeDilation * ushort.MaxValue);
 
@@ -3424,13 +3421,12 @@ namespace OpenSim.Region.ClientStack.LindenUDP
             }
 
             Quaternion rotation = data.Rotation;
+            if (rotation.W == 0.0f && rotation.X == 0.0f && rotation.Y == 0.0f && rotation.Z == 0.0f)
+                rotation = Quaternion.Identity;
 
             if (data.AttachPoint > 30 && data.OwnerID != AgentId) // Someone else's HUD
                 return;
 
-            if (rotation.X == rotation.Y && rotation.Y == rotation.Z && rotation.Z == rotation.W && rotation.W == 0)
-                rotation = Quaternion.Identity;
-
             ImprovedTerseObjectUpdatePacket.ObjectDataBlock objectData = CreateImprovedTerseBlock(data);
 
             lock (m_primTerseUpdates.SyncRoot)
@@ -10238,10 +10234,10 @@ namespace OpenSim.Region.ClientStack.LindenUDP
         {
             internal delegate bool UpdatePriorityHandler(ref TPriority priority, uint local_id);
 
-            private MinHeap<MinHeapItem>[] heaps = new MinHeap<MinHeapItem>[1];
-            private Dictionary<uint, LookupItem> lookup_table = new Dictionary<uint, LookupItem>();
-            private Comparison<TPriority> comparison;
-            private object sync_root = new object();
+            private MinHeap<MinHeapItem>[] m_heaps = new MinHeap<MinHeapItem>[1];
+            private Dictionary<uint, LookupItem> m_lookupTable;
+            private Comparison<TPriority> m_comparison;
+            private object m_syncRoot = new object();
 
             internal PriorityQueue() :
                 this(MinHeap<MinHeapItem>.DEFAULT_CAPACITY, Comparer<TPriority>.Default) { }
@@ -10255,19 +10251,21 @@ namespace OpenSim.Region.ClientStack.LindenUDP
                 this(capacity, new Comparison<TPriority>(comparer.Compare)) { }
             internal PriorityQueue(int capacity, Comparison<TPriority> comparison)
             {
-                for (int i = 0; i < heaps.Length; ++i)
-                    heaps[i] = new MinHeap<MinHeapItem>(capacity);
-                this.comparison = comparison;
+                m_lookupTable = new Dictionary<uint, LookupItem>(capacity);
+
+                for (int i = 0; i < m_heaps.Length; ++i)
+                    m_heaps[i] = new MinHeap<MinHeapItem>(capacity);
+                this.m_comparison = comparison;
             }
 
-            internal object SyncRoot { get { return this.sync_root; } }
+            internal object SyncRoot { get { return this.m_syncRoot; } }
             internal int Count
             {
                 get
                 {
                     int count = 0;
-                    for (int i = 0; i < heaps.Length; ++i)
-                        count = heaps[i].Count;
+                    for (int i = 0; i < m_heaps.Length; ++i)
+                        count = m_heaps[i].Count;
                     return count;
                 }
             }
@@ -10276,36 +10274,36 @@ namespace OpenSim.Region.ClientStack.LindenUDP
             {
                 LookupItem item;
 
-                if (lookup_table.TryGetValue(local_id, out item))
+                if (m_lookupTable.TryGetValue(local_id, out item))
                 {
-                    item.Heap[item.Handle] = new MinHeapItem(priority, value, local_id, this.comparison);
+                    item.Heap[item.Handle] = new MinHeapItem(priority, value, local_id, this.m_comparison);
                     return false;
                 }
                 else
                 {
-                    item.Heap = heaps[0];
-                    item.Heap.Add(new MinHeapItem(priority, value, local_id, this.comparison), ref item.Handle);
-                    lookup_table.Add(local_id, item);
+                    item.Heap = m_heaps[0];
+                    item.Heap.Add(new MinHeapItem(priority, value, local_id, this.m_comparison), ref item.Handle);
+                    m_lookupTable.Add(local_id, item);
                     return true;
                 }
             }
 
             internal TValue Peek()
             {
-                for (int i = 0; i < heaps.Length; ++i)
-                    if (heaps[i].Count > 0)
-                        return heaps[i].Min().Value;
+                for (int i = 0; i < m_heaps.Length; ++i)
+                    if (m_heaps[i].Count > 0)
+                        return m_heaps[i].Min().Value;
                 throw new InvalidOperationException(string.Format("The {0} is empty", this.GetType().ToString()));
             }
 
             internal TValue Dequeue()
             {
-                for (int i = 0; i < heaps.Length; ++i)
+                for (int i = 0; i < m_heaps.Length; ++i)
                 {
-                    if (heaps[i].Count > 0)
+                    if (m_heaps[i].Count > 0)
                     {
-                        MinHeapItem item = heaps[i].RemoveMin();
-                        lookup_table.Remove(item.LocalID);
+                        MinHeapItem item = m_heaps[i].RemoveMin();
+                        m_lookupTable.Remove(item.LocalID);
                         return item.Value;
                     }
                 }
@@ -10317,7 +10315,7 @@ namespace OpenSim.Region.ClientStack.LindenUDP
                 MinHeapItem item;
                 TPriority priority;
 
-                foreach (LookupItem lookup in new List<LookupItem>(this.lookup_table.Values))
+                foreach (LookupItem lookup in new List<LookupItem>(this.m_lookupTable.Values))
                 {
                     if (lookup.Heap.TryGetValue(lookup.Handle, out item))
                     {
@@ -10332,7 +10330,7 @@ namespace OpenSim.Region.ClientStack.LindenUDP
                         {
                             m_log.Warn("[LLCLIENTVIEW]: UpdatePriorityHandler returned false, dropping update");
                             lookup.Heap.Remove(lookup.Handle);
-                            this.lookup_table.Remove(item.LocalID);
+                            this.m_lookupTable.Remove(item.LocalID);
                         }
                     }
                 }
diff --git a/OpenSim/Region/ClientStack/LindenUDP/LLImageManager.cs b/OpenSim/Region/ClientStack/LindenUDP/LLImageManager.cs
index d25bf95..938cf50 100644
--- a/OpenSim/Region/ClientStack/LindenUDP/LLImageManager.cs
+++ b/OpenSim/Region/ClientStack/LindenUDP/LLImageManager.cs
@@ -51,7 +51,6 @@ namespace OpenSim.Region.ClientStack.LindenUDP
 
         private static readonly ILog m_log = LogManager.GetLogger(MethodBase.GetCurrentMethod().DeclaringType);
         private bool m_shuttingdown;
-        private long m_lastloopprocessed;
         private AssetBase m_missingImage;
         private LLClientView m_client; //Client we're assigned to
         private IAssetService m_assetCache; //Asset Cache
@@ -169,7 +168,6 @@ namespace OpenSim.Region.ClientStack.LindenUDP
 
         public bool ProcessImageQueue(int packetsToSend)
         {
-            m_lastloopprocessed = DateTime.Now.Ticks;
             int packetsSent = 0;
 
             while (packetsSent < packetsToSend)
diff --git a/OpenSim/Region/ClientStack/LindenUDP/LLUDPClient.cs b/OpenSim/Region/ClientStack/LindenUDP/LLUDPClient.cs
index 9476eed..4b6a358 100644
--- a/OpenSim/Region/ClientStack/LindenUDP/LLUDPClient.cs
+++ b/OpenSim/Region/ClientStack/LindenUDP/LLUDPClient.cs
@@ -506,8 +506,13 @@ namespace OpenSim.Region.ClientStack.LindenUDP
         /// for</param>
         private void BeginFireQueueEmpty(int throttleIndex)
         {
-            if (!m_onQueueEmptyRunning[throttleIndex])
-                Util.FireAndForget(FireQueueEmpty, throttleIndex);
+            // Unknown is -1 and Resend is 0. Make sure we are only firing the 
+            // callback for categories other than those
+            if (throttleIndex > 0)
+            {
+                if (!m_onQueueEmptyRunning[throttleIndex])
+                    Util.FireAndForget(FireQueueEmpty, throttleIndex);
+            }
         }
 
         /// <summary>
diff --git a/OpenSim/Region/ClientStack/LindenUDP/LLUDPServer.cs b/OpenSim/Region/ClientStack/LindenUDP/LLUDPServer.cs
index 66e1468..74175d0 100644
--- a/OpenSim/Region/ClientStack/LindenUDP/LLUDPServer.cs
+++ b/OpenSim/Region/ClientStack/LindenUDP/LLUDPServer.cs
@@ -107,7 +107,7 @@ namespace OpenSim.Region.ClientStack.LindenUDP
         /// <summary>Manages authentication for agent circuits</summary>
         private AgentCircuitManager m_circuitManager;
         /// <summary>Reference to the scene this UDP server is attached to</summary>
-        private IScene m_scene;
+        private Scene m_scene;
         /// <summary>The X/Y coordinates of the scene this UDP server is attached to</summary>
         private Location m_location;
         /// <summary>The measured resolution of Environment.TickCount</summary>
@@ -184,15 +184,20 @@ namespace OpenSim.Region.ClientStack.LindenUDP
 
         public void AddScene(IScene scene)
         {
-            if (m_scene == null)
+            if (m_scene != null)
             {
-                m_scene = scene;
-                m_location = new Location(m_scene.RegionInfo.RegionHandle);
+                m_log.Error("[LLUDPSERVER]: AddScene() called on an LLUDPServer that already has a scene");
+                return;
             }
-            else
+
+            if (!(scene is Scene))
             {
-                m_log.Error("[LLUDPSERVER]: AddScene() called on an LLUDPServer that already has a scene");
+                m_log.Error("[LLUDPSERVER]: AddScene() called with an unrecognized scene type " + scene.GetType());
+                return;
             }
+
+            m_scene = (Scene)scene;
+            m_location = new Location(m_scene.RegionInfo.RegionHandle);
         }
 
         public bool HandlesRegion(Location x)
@@ -794,7 +799,7 @@ namespace OpenSim.Region.ClientStack.LindenUDP
                     elapsed500MS = 0;
                 }
 
-                m_scene.ClientManager.ForEach(
+                m_scene.ClientManager.ForEachSync(
                     delegate(IClientAPI client)
                     {
                         if (client is LLClientView)