4 files changed, 130 insertions, 25 deletions

diff --git a/OpenSim/Framework/Pool.cs b/OpenSim/Framework/Pool.cs
new file mode 100644
index 0000000..1ca06c3
--- /dev/null
+++ b/OpenSim/Framework/Pool.cs
@@ -0,0 +1,76 @@
+/*
+ * 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.Framework
+{
+    /// <summary>
+    /// Naive pool implementation.
+    /// </summary>
+    /// <remarks>
+    /// Currently assumes that objects are in a useable state when returned.
+    /// </remarks>
+    public class Pool<T>
+    {
+        private Stack<T> m_pool;
+
+        private int m_maxPoolSize;
+
+        private Func<T> m_createFunction;
+
+        public Pool(Func<T> createFunction, int maxSize)
+        {
+            m_maxPoolSize = maxSize;
+            m_createFunction = createFunction;
+            m_pool = new Stack<T>(m_maxPoolSize);
+        }
+
+        public T GetObject()
+        {
+            lock (m_pool)
+            {
+                if (m_pool.Count > 0)
+                    return m_pool.Pop();
+                else
+                    return m_createFunction();
+            }
+        }
+
+        public void ReturnObject(T obj)
+        {
+            lock (m_pool)
+            {
+                if (m_pool.Count >= m_maxPoolSize)
+                    return;
+                else
+                    m_pool.Push(obj);
+            }
+        }
+    }
+}
\ No newline at end of file
diff --git a/OpenSim/Region/ClientStack/Linden/UDP/LLUDPServer.cs b/OpenSim/Region/ClientStack/Linden/UDP/LLUDPServer.cs
index fc6dd4d..42247ca 100644
--- a/OpenSim/Region/ClientStack/Linden/UDP/LLUDPServer.cs
+++ b/OpenSim/Region/ClientStack/Linden/UDP/LLUDPServer.cs
@@ -188,7 +188,9 @@ namespace OpenSim.Region.ClientStack.LindenUDP
         /// </summary>
         private IClientAPI m_currentIncomingClient;
 
-        public LLUDPServer(IPAddress listenIP, ref uint port, int proxyPortOffsetParm, bool allow_alternate_port, IConfigSource configSource, AgentCircuitManager circuitManager)
+        public LLUDPServer(
+            IPAddress listenIP, ref uint port, int proxyPortOffsetParm, bool allow_alternate_port,
+            IConfigSource configSource, AgentCircuitManager circuitManager)
             : base(listenIP, (int)port)
         {
             #region Environment.TickCount Measurement
@@ -242,6 +244,7 @@ namespace OpenSim.Region.ClientStack.LindenUDP
             {
                 PacketPool.Instance.RecyclePackets = packetConfig.GetBoolean("RecyclePackets", true);
                 PacketPool.Instance.RecycleDataBlocks = packetConfig.GetBoolean("RecycleDataBlocks", true);
+                UsePools = packetConfig.GetBoolean("RecycleBaseUDPPackets", false);
             }
 
             #region BinaryStats
@@ -284,8 +287,8 @@ namespace OpenSim.Region.ClientStack.LindenUDP
         private void StartInbound()
         {
             m_log.InfoFormat(
-                "[LLUDPSERVER]: Starting inbound packet processing for the LLUDP server in {0} mode",
-                m_asyncPacketHandling ? "asynchronous" : "synchronous");
+                "[LLUDPSERVER]: Starting inbound packet processing for the LLUDP server in {0} mode with UsePools = {1}",
+                m_asyncPacketHandling ? "asynchronous" : "synchronous", UsePools);
 
             base.StartInbound(m_recvBufferSize, m_asyncPacketHandling);
 
@@ -300,7 +303,7 @@ namespace OpenSim.Region.ClientStack.LindenUDP
                 Watchdog.DEFAULT_WATCHDOG_TIMEOUT_MS);
         }
 
-        private void StartOutbound()
+        private new void StartOutbound()
         {
             m_log.Info("[LLUDPSERVER]: Starting outbound packet processing for the LLUDP server");
 
@@ -317,7 +320,7 @@ namespace OpenSim.Region.ClientStack.LindenUDP
                 Watchdog.DEFAULT_WATCHDOG_TIMEOUT_MS);
         }
 
-        public new void Stop()
+        public void Stop()
         {
             m_log.Info("[LLUDPSERVER]: Shutting down the LLUDP server for " + m_scene.RegionInfo.RegionName);
             base.StopOutbound();
@@ -806,7 +809,7 @@ namespace OpenSim.Region.ClientStack.LindenUDP
             LLUDPClient udpClient = null;
             Packet packet = null;
             int packetEnd = buffer.DataLength - 1;
-            IPEndPoint address = (IPEndPoint)buffer.RemoteEndPoint;
+            IPEndPoint endPoint = (IPEndPoint)buffer.RemoteEndPoint;
 
             #region Decoding
 
@@ -816,7 +819,7 @@ namespace OpenSim.Region.ClientStack.LindenUDP
 //                    "[LLUDPSERVER]: Dropping undersized packet with {0} bytes received from {1} in {2}",
 //                    buffer.DataLength, buffer.RemoteEndPoint, m_scene.RegionInfo.RegionName);
 
-                return; // Drop undersizd packet
+                return; // Drop undersized packet
             }
 
             int headerLen = 7;
@@ -842,6 +845,9 @@ namespace OpenSim.Region.ClientStack.LindenUDP
 //                packet = Packet.BuildPacket(buffer.Data, ref packetEnd,
 //                    // Only allocate a buffer for zerodecoding if the packet is zerocoded
 //                    ((buffer.Data[0] & Helpers.MSG_ZEROCODED) != 0) ? new byte[4096] : null);
+                // If OpenSimUDPBase.UsePool == true (which is currently separate from the PacketPool) then we
+                // assume that packet construction does not retain a reference to byte[] buffer.Data (instead, all
+                // bytes are copied out).
                 packet = PacketPool.Instance.GetPacket(buffer.Data, ref packetEnd,
                     // Only allocate a buffer for zerodecoding if the packet is zerocoded
                     ((buffer.Data[0] & Helpers.MSG_ZEROCODED) != 0) ? new byte[4096] : null);
@@ -884,7 +890,9 @@ namespace OpenSim.Region.ClientStack.LindenUDP
             // UseCircuitCode handling
             if (packet.Type == PacketType.UseCircuitCode)
             {
-                object[] array = new object[] { buffer, packet };
+                // We need to copy the endpoint so that it doesn't get changed when another thread reuses the
+                // buffer.
+                object[] array = new object[] { new IPEndPoint(endPoint.Address, endPoint.Port), packet };
 
                 Util.FireAndForget(HandleUseCircuitCode, array);
 
@@ -893,7 +901,7 @@ namespace OpenSim.Region.ClientStack.LindenUDP
 
             // Determine which agent this packet came from
             IClientAPI client;
-            if (!m_scene.TryGetClient(address, out client) || !(client is LLClientView))
+            if (!m_scene.TryGetClient(endPoint, out client) || !(client is LLClientView))
             {
                 //m_log.Debug("[LLUDPSERVER]: Received a " + packet.Type + " packet from an unrecognized source: " + address + " in " + m_scene.RegionInfo.RegionName);
                 return;
@@ -1091,21 +1099,19 @@ namespace OpenSim.Region.ClientStack.LindenUDP
 
         private void HandleUseCircuitCode(object o)
         {
-            IPEndPoint remoteEndPoint = null;
+            IPEndPoint endPoint = null;
             IClientAPI client = null;
 
             try
             {
     //            DateTime startTime = DateTime.Now;
                 object[] array = (object[])o;
-                UDPPacketBuffer buffer = (UDPPacketBuffer)array[0];
+                endPoint = (IPEndPoint)array[0];
                 UseCircuitCodePacket uccp = (UseCircuitCodePacket)array[1];
 
                 m_log.DebugFormat(
                     "[LLUDPSERVER]: Handling UseCircuitCode request for circuit {0} to {1} from IP {2}",
-                    uccp.CircuitCode.Code, m_scene.RegionInfo.RegionName, buffer.RemoteEndPoint);
-    
-                remoteEndPoint = (IPEndPoint)buffer.RemoteEndPoint;
+                    uccp.CircuitCode.Code, m_scene.RegionInfo.RegionName, endPoint);
     
                 AuthenticateResponse sessionInfo;
                 if (IsClientAuthorized(uccp, out sessionInfo))
@@ -1116,13 +1122,13 @@ namespace OpenSim.Region.ClientStack.LindenUDP
                             uccp.CircuitCode.Code,
                             uccp.CircuitCode.ID,
                             uccp.CircuitCode.SessionID,
-                            remoteEndPoint,
+                            endPoint,
                             sessionInfo);
             
                     // Send ack straight away to let the viewer know that the connection is active.
                     // The client will be null if it already exists (e.g. if on a region crossing the client sends a use
                     // circuit code to the existing child agent.  This is not particularly obvious.
-                    SendAckImmediate(remoteEndPoint, uccp.Header.Sequence);
+                    SendAckImmediate(endPoint, uccp.Header.Sequence);
             
                     // We only want to send initial data to new clients, not ones which are being converted from child to root.
                     if (client != null)
@@ -1133,7 +1139,7 @@ namespace OpenSim.Region.ClientStack.LindenUDP
                     // Don't create clients for unauthorized requesters.
                     m_log.WarnFormat(
                         "[LLUDPSERVER]: Ignoring connection request for {0} to {1} with unknown circuit code {2} from IP {3}",
-                        uccp.CircuitCode.ID, m_scene.RegionInfo.RegionName, uccp.CircuitCode.Code, remoteEndPoint);
+                        uccp.CircuitCode.ID, m_scene.RegionInfo.RegionName, uccp.CircuitCode.Code, endPoint);
                 }
     
                 //            m_log.DebugFormat(
@@ -1145,7 +1151,7 @@ namespace OpenSim.Region.ClientStack.LindenUDP
             {
                 m_log.ErrorFormat(
                     "[LLUDPSERVER]: UseCircuitCode handling from endpoint {0}, client {1} {2} failed.  Exception {3}{4}",
-                    remoteEndPoint != null ? remoteEndPoint.ToString() : "n/a",
+                    endPoint != null ? endPoint.ToString() : "n/a",
                     client != null ? client.Name : "unknown",
                     client != null ? client.AgentId.ToString() : "unknown",
                     e.Message,
diff --git a/OpenSim/Region/ClientStack/Linden/UDP/OpenSimUDPBase.cs b/OpenSim/Region/ClientStack/Linden/UDP/OpenSimUDPBase.cs
index 828c23c..6e6b3ef 100644
--- a/OpenSim/Region/ClientStack/Linden/UDP/OpenSimUDPBase.cs
+++ b/OpenSim/Region/ClientStack/Linden/UDP/OpenSimUDPBase.cs
@@ -30,6 +30,7 @@ using System.Net;
 using System.Net.Sockets;
 using System.Threading;
 using log4net;
+using OpenSim.Framework;
 
 namespace OpenMetaverse
 {
@@ -58,6 +59,16 @@ namespace OpenMetaverse
         /// <summary>Flag to process packets asynchronously or synchronously</summary>
         private bool m_asyncPacketHandling;
 
+        /// <summary>
+        /// Pool to use for handling data.  May be null if UsePools = false;
+        /// </summary>
+        protected OpenSim.Framework.Pool<UDPPacketBuffer> m_pool;
+
+        /// <summary>
+        /// Are we to use object pool(s) to reduce memory churn when receiving data?
+        /// </summary>
+        public bool UsePools { get; protected set; }
+
         /// <summary>Returns true if the server is currently listening for inbound packets, otherwise false</summary>
         public bool IsRunningInbound { get; private set; }
 
@@ -70,6 +81,7 @@ namespace OpenMetaverse
         /// </summary>
         /// <param name="bindAddress">Local IP address to bind the server to</param>
         /// <param name="port">Port to listening for incoming UDP packets on</param>
+        /// /// <param name="usePool">Are we to use an object pool to get objects for handing inbound data?</param>
         public OpenSimUDPBase(IPAddress bindAddress, int port)
         {
             m_localBindAddress = bindAddress;
@@ -94,6 +106,11 @@ namespace OpenMetaverse
         /// necessary</remarks>
         public void StartInbound(int recvBufferSize, bool asyncPacketHandling)
         {
+            if (UsePools)
+                m_pool = new Pool<UDPPacketBuffer>(() => new UDPPacketBuffer(), 500);
+            else
+                m_pool = null;
+
             m_asyncPacketHandling = asyncPacketHandling;
 
             if (!IsRunningInbound)
@@ -165,9 +182,12 @@ namespace OpenMetaverse
 
         private void AsyncBeginReceive()
         {
-            // allocate a packet buffer
-            //WrappedObject<UDPPacketBuffer> wrappedBuffer = Pool.CheckOut();
-            UDPPacketBuffer buf = new UDPPacketBuffer();
+            UDPPacketBuffer buf;
+
+            if (UsePools)
+                buf = m_pool.GetObject();
+            else
+                buf = new UDPPacketBuffer();
 
             if (IsRunningInbound)
             {
@@ -231,8 +251,6 @@ namespace OpenMetaverse
 
                 // get the buffer that was created in AsyncBeginReceive
                 // this is the received data
-                //WrappedObject<UDPPacketBuffer> wrappedBuffer = (WrappedObject<UDPPacketBuffer>)iar.AsyncState;
-                //UDPPacketBuffer buffer = wrappedBuffer.Instance;
                 UDPPacketBuffer buffer = (UDPPacketBuffer)iar.AsyncState;
 
                 try
@@ -249,7 +267,8 @@ namespace OpenMetaverse
                 catch (ObjectDisposedException) { }
                 finally
                 {
-                    //wrappedBuffer.Dispose();
+                    if (UsePools)
+                        m_pool.ReturnObject(buffer);
 
                     // Synchronous mode waits until the packet callback completes
                     // before starting the receive to fetch another packet
diff --git a/bin/OpenSimDefaults.ini b/bin/OpenSimDefaults.ini
index 2fca6ce..b99a02e 100644
--- a/bin/OpenSimDefaults.ini
+++ b/bin/OpenSimDefaults.ini
@@ -1602,10 +1602,14 @@
 
 
 [PacketPool]
-    ; Enables the experimental packet pool. Yes, we've been here before.
     ;RecyclePackets = true;
     ;RecycleDataBlocks = true;
 
+    ; If true, then the basic packet objects used to receive data are also recycled, not just the LLUDP packets.
+    ; This reduces data churn
+    ; This setting is currently experimental and defaults to false.
+    RecycleBaseUDPPackets = false;
+
 
 [InterestManagement]
      ; This section controls how state updates are prioritized for each client