2 files changed, 139 insertions, 14 deletions

diff --git a/OpenSim/Framework/ClientManager.cs b/OpenSim/Framework/ClientManager.cs
index fd5f87f..367bc6a 100644
--- a/OpenSim/Framework/ClientManager.cs
+++ b/OpenSim/Framework/ClientManager.cs
@@ -121,20 +121,10 @@ namespace OpenSim.Framework
         /// <summary>
         /// Remove a client from the collection
         /// </summary>
-        /// <param name="value">Reference to the client object</param>
-        public void Remove(IClientAPI value)
-        {
-            lock (m_writeLock)
-            {
-                if (m_dict.ContainsKey(value.AgentId))
-                    m_dict = m_dict.Delete(value.AgentId);
-
-                if (m_dict2.ContainsKey(value.RemoteEndPoint))
-                    m_dict2 = m_dict2.Delete(value.RemoteEndPoint);
-            }
-        }
-
-        public void Remove(UUID key)
+        /// <param name="key">UUID of the client to remove</param>
+        /// <returns>True if a client was removed, or false if the given UUID
+        /// was not present in the collection</returns>
+        public bool Remove(UUID key)
         {
             lock (m_writeLock)
             {
@@ -144,6 +134,11 @@ namespace OpenSim.Framework
                 {
                     m_dict = m_dict.Delete(key);
                     m_dict2 = m_dict2.Delete(client.RemoteEndPoint);
+                    return true;
+                }
+                else
+                {
+                    return false;
                 }
             }
         }
diff --git a/OpenSim/Framework/LocklessQueue.cs b/OpenSim/Framework/LocklessQueue.cs
new file mode 100644
index 0000000..dd3d201
--- /dev/null
+++ b/OpenSim/Framework/LocklessQueue.cs
@@ -0,0 +1,130 @@
+/*
+ * Copyright (c) 2009, openmetaverse.org
+ * 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.Threading;
+
+namespace OpenSim.Framework
+{
+    public sealed class LocklessQueue<T>
+    {
+        private sealed class SingleLinkNode
+        {
+            public SingleLinkNode Next;
+            public T Item;
+        }
+
+        SingleLinkNode head;
+        SingleLinkNode tail;
+        int count;
+
+        public int Count { get { return count; } }
+
+        public LocklessQueue()
+        {
+            Init();
+        }
+
+        public void Enqueue(T item)
+        {
+            SingleLinkNode oldTail = null;
+            SingleLinkNode oldTailNext;
+
+            SingleLinkNode newNode = new SingleLinkNode();
+            newNode.Item = item;
+
+            bool newNodeWasAdded = false;
+
+            while (!newNodeWasAdded)
+            {
+                oldTail = tail;
+                oldTailNext = oldTail.Next;
+
+                if (tail == oldTail)
+                {
+                    if (oldTailNext == null)
+                        newNodeWasAdded = CAS(ref tail.Next, null, newNode);
+                    else
+                        CAS(ref tail, oldTail, oldTailNext);
+                }
+            }
+
+            CAS(ref tail, oldTail, newNode);
+            Interlocked.Increment(ref count);
+        }
+
+        public bool Dequeue(out T item)
+        {
+            item = default(T);
+            SingleLinkNode oldHead = null;
+            bool haveAdvancedHead = false;
+
+            while (!haveAdvancedHead)
+            {
+                oldHead = head;
+                SingleLinkNode oldTail = tail;
+                SingleLinkNode oldHeadNext = oldHead.Next;
+
+                if (oldHead == head)
+                {
+                    if (oldHead == oldTail)
+                    {
+                        if (oldHeadNext == null)
+                            return false;
+
+                        CAS(ref tail, oldTail, oldHeadNext);
+                    }
+                    else
+                    {
+                        item = oldHeadNext.Item;
+                        haveAdvancedHead = CAS(ref head, oldHead, oldHeadNext);
+                    }
+                }
+            }
+
+            Interlocked.Decrement(ref count);
+            return true;
+        }
+
+        public void Clear()
+        {
+            Init();
+        }
+
+        private void Init()
+        {
+            count = 0;
+            head = tail = new SingleLinkNode();
+        }
+
+        private static bool CAS(ref SingleLinkNode location, SingleLinkNode comparand, SingleLinkNode newValue)
+        {
+            return
+                (object)comparand ==
+                (object)Interlocked.CompareExchange<SingleLinkNode>(ref location, newValue, comparand);
+        }
+    }
+}
\ No newline at end of file