First pass at cleaning up thread safety in EntityManager and SceneGraph

22 files changed, 245 insertions, 369 deletions

diff --git a/OpenSim/Region/CoreModules/Avatar/Attachments/AttachmentsModule.cs b/OpenSim/Region/CoreModules/Avatar/Attachments/AttachmentsModule.cs
index dd7d831..7270304 100644
--- a/OpenSim/Region/CoreModules/Avatar/Attachments/AttachmentsModule.cs
+++ b/OpenSim/Region/CoreModules/Avatar/Attachments/AttachmentsModule.cs
@@ -436,7 +436,7 @@ namespace OpenSim.Region.CoreModules.Avatar.Attachments
 
             // We can NOT use the dictionries here, as we are looking
             // for an entity by the fromAssetID, which is NOT the prim UUID
-            List<EntityBase> detachEntities = m_scene.GetEntities();
+            EntityBase[] detachEntities = m_scene.GetEntities();
             SceneObjectGroup group;
 
             foreach (EntityBase entity in detachEntities)
diff --git a/OpenSim/Region/CoreModules/World/Archiver/ArchiveWriteRequestPreparation.cs b/OpenSim/Region/CoreModules/World/Archiver/ArchiveWriteRequestPreparation.cs
index b25636f..283b33b 100644
--- a/OpenSim/Region/CoreModules/World/Archiver/ArchiveWriteRequestPreparation.cs
+++ b/OpenSim/Region/CoreModules/World/Archiver/ArchiveWriteRequestPreparation.cs
@@ -102,7 +102,7 @@ namespace OpenSim.Region.CoreModules.World.Archiver
         {
             Dictionary<UUID, AssetType> assetUuids = new Dictionary<UUID, AssetType>();
 
-            List<EntityBase> entities = m_scene.GetEntities();
+            EntityBase[] entities = m_scene.GetEntities();
             List<SceneObjectGroup> sceneObjects = new List<SceneObjectGroup>();
 
             /*
diff --git a/OpenSim/Region/CoreModules/World/Land/LandManagementModule.cs b/OpenSim/Region/CoreModules/World/Land/LandManagementModule.cs
index da7a284..ea71fd9 100644
--- a/OpenSim/Region/CoreModules/World/Land/LandManagementModule.cs
+++ b/OpenSim/Region/CoreModules/World/Land/LandManagementModule.cs
@@ -794,7 +794,8 @@ namespace OpenSim.Region.CoreModules.World.Land
         public void EventManagerOnParcelPrimCountUpdate()
         {
             ResetAllLandPrimCounts();
-            foreach (EntityBase obj in m_scene.Entities)
+            EntityBase[] entities = m_scene.Entities.GetEntities();
+            foreach (EntityBase obj in entities)
             {
                 if (obj != null)
                 {
diff --git a/OpenSim/Region/CoreModules/World/Serialiser/SerialiseObjects.cs b/OpenSim/Region/CoreModules/World/Serialiser/SerialiseObjects.cs
index bef7fe4..5067ebd 100644
--- a/OpenSim/Region/CoreModules/World/Serialiser/SerialiseObjects.cs
+++ b/OpenSim/Region/CoreModules/World/Serialiser/SerialiseObjects.cs
@@ -80,7 +80,7 @@ namespace OpenSim.Region.CoreModules.World.Serialiser
         {
             string xmlstream = "<scene>";
 
-            List<EntityBase> EntityList = scene.GetEntities();
+            EntityBase[] EntityList = scene.GetEntities();
             List<string> EntityXml = new List<string>();
 
             foreach (EntityBase ent in EntityList)
diff --git a/OpenSim/Region/CoreModules/World/Serialiser/SerialiserModule.cs b/OpenSim/Region/CoreModules/World/Serialiser/SerialiserModule.cs
index 58e4261..98fe493 100644
--- a/OpenSim/Region/CoreModules/World/Serialiser/SerialiserModule.cs
+++ b/OpenSim/Region/CoreModules/World/Serialiser/SerialiserModule.cs
@@ -165,12 +165,12 @@ namespace OpenSim.Region.CoreModules.World.Serialiser
             return SceneXmlLoader.SaveGroupToXml2(grp);
         }
 
-        public void SavePrimListToXml2(List<EntityBase> entityList, string fileName)
+        public void SavePrimListToXml2(EntityBase[] entityList, string fileName)
         {
             SceneXmlLoader.SavePrimListToXml2(entityList, fileName);
         }
 
-        public void SavePrimListToXml2(List<EntityBase> entityList, TextWriter stream, Vector3 min, Vector3 max)
+        public void SavePrimListToXml2(EntityBase[] entityList, TextWriter stream, Vector3 min, Vector3 max)
         {
             SceneXmlLoader.SavePrimListToXml2(entityList, stream, min, max);
         }
diff --git a/OpenSim/Region/CoreModules/World/WorldMap/MapImageModule.cs b/OpenSim/Region/CoreModules/World/WorldMap/MapImageModule.cs
index 57eff8a..1d9c2bd 100644
--- a/OpenSim/Region/CoreModules/World/WorldMap/MapImageModule.cs
+++ b/OpenSim/Region/CoreModules/World/WorldMap/MapImageModule.cs
@@ -212,7 +212,7 @@ namespace OpenSim.Region.CoreModules.World.WorldMap
             double[,] hm = whichScene.Heightmap.GetDoubles();
             tc = Environment.TickCount;
             m_log.Info("[MAPTILE]: Generating Maptile Step 2: Object Volume Profile");
-            List<EntityBase> objs = whichScene.GetEntities();
+            EntityBase[] objs = whichScene.GetEntities();
             Dictionary<uint, DrawStruct> z_sort = new Dictionary<uint, DrawStruct>();
             //SortedList<float, RectangleDrawStruct> z_sort = new SortedList<float, RectangleDrawStruct>();
             List<float> z_sortheights = new List<float>();
diff --git a/OpenSim/Region/DataSnapshot/ObjectSnapshot.cs b/OpenSim/Region/DataSnapshot/ObjectSnapshot.cs
index 3c39f9e..5e75cae 100644
--- a/OpenSim/Region/DataSnapshot/ObjectSnapshot.cs
+++ b/OpenSim/Region/DataSnapshot/ObjectSnapshot.cs
@@ -101,7 +101,8 @@ namespace OpenSim.Region.DataSnapshot.Providers
             XmlNode parent = nodeFactory.CreateNode(XmlNodeType.Element, "objectdata", "");
             XmlNode node;
 
-            foreach (EntityBase entity in m_scene.Entities)
+            EntityBase[] entities = m_scene.Entities.GetEntities();
+            foreach (EntityBase entity in entities)
             {
                 // only objects, not avatars
                 if (entity is SceneObjectGroup)
diff --git a/OpenSim/Region/Framework/Interfaces/IRegionSerialiserModule.cs b/OpenSim/Region/Framework/Interfaces/IRegionSerialiserModule.cs
index e7562a5..18758c8 100644
--- a/OpenSim/Region/Framework/Interfaces/IRegionSerialiserModule.cs
+++ b/OpenSim/Region/Framework/Interfaces/IRegionSerialiserModule.cs
@@ -90,7 +90,7 @@ namespace OpenSim.Region.Framework.Interfaces
         /// </summary>
         /// <param name="entityList"></param>
         /// <param name="fileName"></param>
-        void SavePrimListToXml2(List<EntityBase> entityList, string fileName);
+        void SavePrimListToXml2(EntityBase[] entityList, string fileName);
 
         /// <summary>
         /// Save a set of prims in the xml2 format, optionally specifying a bounding box for which
@@ -101,7 +101,7 @@ namespace OpenSim.Region.Framework.Interfaces
         /// <param name="stream"></param>
         /// <param name="min"></param>
         /// <param name="max"></param>
-        void SavePrimListToXml2(List<EntityBase> entityList, TextWriter stream, Vector3 min, Vector3 max);
+        void SavePrimListToXml2(EntityBase[] entityList, TextWriter stream, Vector3 min, Vector3 max);
         
         void SaveNamedPrimsToXml2(Scene scene, string primName, string fileName);
             
diff --git a/OpenSim/Region/Framework/Scenes/EntityManager.cs b/OpenSim/Region/Framework/Scenes/EntityManager.cs
index 099fcce..85d0a4f 100644
--- a/OpenSim/Region/Framework/Scenes/EntityManager.cs
+++ b/OpenSim/Region/Framework/Scenes/EntityManager.cs
@@ -34,187 +34,89 @@ using OpenMetaverse;
 
 namespace OpenSim.Region.Framework.Scenes
 {
-    public class EntityManager : IEnumerable<EntityBase>
+    public class EntityManager //: IEnumerable<EntityBase>
     {
         private static readonly ILog m_log = LogManager.GetLogger(MethodBase.GetCurrentMethod().DeclaringType);
-        private readonly Dictionary<UUID,EntityBase> m_eb_uuid = new Dictionary<UUID, EntityBase>();
-        private readonly Dictionary<uint, EntityBase> m_eb_localID = new Dictionary<uint, EntityBase>();
-        //private readonly Dictionary<UUID, ScenePresence> m_pres_uuid = new Dictionary<UUID, ScenePresence>();
-        private readonly Object m_lock = new Object();
+        private readonly DoubleDictionary<UUID, uint, EntityBase> m_entities = new DoubleDictionary<UUID, uint, EntityBase>();
 
-        [Obsolete("Use Add() instead.")]
-        public void Add(UUID id, EntityBase eb)
+        public int Count
         {
-            Add(eb);
+            get { return m_entities.Count; }
         }
 
         public void Add(EntityBase entity)
         {
-            lock (m_lock)
-            {
-                try
-                {
-                    m_eb_uuid.Add(entity.UUID, entity);
-                    m_eb_localID.Add(entity.LocalId, entity);
-                }
-                catch(Exception e)
-                {
-                    m_log.ErrorFormat("Add Entity failed: {0}", e.Message);
-                }
-            }
-        }
-
-        public void InsertOrReplace(EntityBase entity)
-        {
-            lock (m_lock)
-            {
-                try
-                {
-                    m_eb_uuid[entity.UUID] = entity;
-                    m_eb_localID[entity.LocalId] = entity;
-                }
-                catch(Exception e)
-                {
-                    m_log.ErrorFormat("Insert or Replace Entity failed: {0}", e.Message);
-                }
-            }
+            m_entities.Add(entity.UUID, entity.LocalId, entity);
         }
 
         public void Clear()
         {
-            lock (m_lock)
-            {
-                m_eb_uuid.Clear();
-                m_eb_localID.Clear();
-            }
-        }
-
-        public int Count
-        {
-            get
-            {
-                return m_eb_uuid.Count;
-            }
+            m_entities.Clear();
         }
 
         public bool ContainsKey(UUID id)
         {
-            try
-            {
-                return m_eb_uuid.ContainsKey(id);
-            }
-            catch
-            {
-                return false;
-            }
+            return m_entities.ContainsKey(id);
         }
 
         public bool ContainsKey(uint localID)
         {
-            try
-            {
-                return m_eb_localID.ContainsKey(localID);
-            }
-            catch
-            {
-                return false;
-            }
+            return m_entities.ContainsKey(localID);
         }
 
         public bool Remove(uint localID)
         {
-            lock (m_lock)
-            {
-                try
-                {
-                    bool a = false;
-                    EntityBase entity;
-                    if (m_eb_localID.TryGetValue(localID, out entity))
-                        a = m_eb_uuid.Remove(entity.UUID);
-
-                    bool b = m_eb_localID.Remove(localID);
-                    return a && b;
-                }
-                catch (Exception e)
-                {
-                    m_log.ErrorFormat("Remove Entity failed for {0}", localID, e);
-                    return false;
-                }
-            }
+            return m_entities.Remove(localID);
         }
 
         public bool Remove(UUID id)
         {
-            lock (m_lock)
-            {
-                try 
-                {
-                    bool a = false;
-                    EntityBase entity;
-                    if (m_eb_uuid.TryGetValue(id, out entity))
-                        a = m_eb_localID.Remove(entity.LocalId);
-
-                    bool b = m_eb_uuid.Remove(id);
-                    return a && b;
-                }
-                catch (Exception e)
-                {
-                    m_log.ErrorFormat("Remove Entity failed for {0}", id, e);
-                    return false;
-                }
-            }
+            return m_entities.Remove(id);
         }
 
-        public List<EntityBase> GetAllByType<T>()
+        public EntityBase[] GetAllByType<T>()
         {
             List<EntityBase> tmp = new List<EntityBase>();
 
-            lock (m_lock)
-            {
-                try
+            m_entities.ForEach(
+                delegate(EntityBase entity)
                 {
-                    foreach (KeyValuePair<UUID, EntityBase> pair in m_eb_uuid)
-                    {
-                        if (pair.Value is T)
-                        {
-                            tmp.Add(pair.Value);
-                        }
-                    }
+                    if (entity is T)
+                        tmp.Add(entity);
                 }
-                catch (Exception e) 
-                {
-                    m_log.ErrorFormat("GetAllByType failed for {0}", e);
-                    tmp = null;
-                }
-            }
+            );
 
-            return tmp;
+            return tmp.ToArray();
         }
 
-        public List<EntityBase> GetEntities()
+        public EntityBase[] GetEntities()
         {
-            lock (m_lock)
-            {
-                return new List<EntityBase>(m_eb_uuid.Values);
-            }
+            List<EntityBase> tmp = new List<EntityBase>(m_entities.Count);
+            m_entities.ForEach(delegate(EntityBase entity) { tmp.Add(entity); });
+            return tmp.ToArray();
+        }
+
+        public void ForEach(Action<EntityBase> action)
+        {
+            m_entities.ForEach(action);
+        }
+
+        public EntityBase Find(Predicate<EntityBase> predicate)
+        {
+            return m_entities.FindValue(predicate);
         }
 
         public EntityBase this[UUID id]
         {
             get
             {
-                lock (m_lock)
-                {
-                    EntityBase entity;
-                    if (m_eb_uuid.TryGetValue(id, out entity))
-                        return entity;
-                    else
-                        return null;
-                }
+                EntityBase entity;
+                m_entities.TryGetValue(id, out entity);
+                return entity;
             }
             set
             {
-                InsertOrReplace(value);
+                Add(value);
             }
         }
 
@@ -222,50 +124,38 @@ namespace OpenSim.Region.Framework.Scenes
         {
             get
             {
-                lock (m_lock)
-                {
-                    EntityBase entity;
-                    if (m_eb_localID.TryGetValue(localID, out entity))
-                        return entity;
-                    else
-                        return null;
-                }
+                EntityBase entity;
+                m_entities.TryGetValue(localID, out entity);
+                return entity;
             }
             set
             {
-                InsertOrReplace(value);
+                Add(value);
             }
         }
 
         public bool TryGetValue(UUID key, out EntityBase obj)
         {
-            lock (m_lock)
-            {
-                return m_eb_uuid.TryGetValue(key, out obj);
-            }
+            return m_entities.TryGetValue(key, out obj);
         }
 
         public bool TryGetValue(uint key, out EntityBase obj)
         {
-            lock (m_lock)
-            {
-                return m_eb_localID.TryGetValue(key, out obj);
-            }
+            return m_entities.TryGetValue(key, out obj);
         }
 
         /// <summary>
         /// This could be optimised to work on the list 'live' rather than making a safe copy and iterating that.
         /// </summary>
         /// <returns></returns>
-        public IEnumerator<EntityBase> GetEnumerator()
-        {
-            return GetEntities().GetEnumerator();
-        }
-
-        IEnumerator IEnumerable.GetEnumerator()
-        {
-            return GetEnumerator();
-        }
-
+        //public IEnumerator<EntityBase> GetEnumerator()
+        //{
+        //    return GetEntities().GetEnumerator();
+        //}
+
+        //IEnumerator IEnumerable.GetEnumerator()
+        //{
+        //    return GetEnumerator();
+        //}
     }
 }
diff --git a/OpenSim/Region/Framework/Scenes/Scene.Inventory.cs b/OpenSim/Region/Framework/Scenes/Scene.Inventory.cs
index c49386a..a439eb9 100644
--- a/OpenSim/Region/Framework/Scenes/Scene.Inventory.cs
+++ b/OpenSim/Region/Framework/Scenes/Scene.Inventory.cs
@@ -58,7 +58,8 @@ namespace OpenSim.Region.Framework.Scenes
         {
             m_log.Info("[PRIM INVENTORY]: Starting scripts in scene");
 
-            foreach (EntityBase group in Entities)
+            EntityBase[] entities = Entities.GetEntities();
+            foreach (EntityBase group in entities)
             {
                 if (group is SceneObjectGroup)
                 {
diff --git a/OpenSim/Region/Framework/Scenes/Scene.PacketHandlers.cs b/OpenSim/Region/Framework/Scenes/Scene.PacketHandlers.cs
index c511774..2f69476 100644
--- a/OpenSim/Region/Framework/Scenes/Scene.PacketHandlers.cs
+++ b/OpenSim/Region/Framework/Scenes/Scene.PacketHandlers.cs
@@ -116,9 +116,8 @@ namespace OpenSim.Region.Framework.Scenes
         /// <param name="remoteClient"></param>
         public void RequestPrim(uint primLocalID, IClientAPI remoteClient)
         {
-            List<EntityBase> EntityList = GetEntities();
-
-            foreach (EntityBase ent in EntityList)
+            EntityBase[] entityList = GetEntities();
+            foreach (EntityBase ent in entityList)
             {
                 if (ent is SceneObjectGroup)
                 {
@@ -138,9 +137,8 @@ namespace OpenSim.Region.Framework.Scenes
         /// <param name="remoteClient"></param>
         public void SelectPrim(uint primLocalID, IClientAPI remoteClient)
         {
-            List<EntityBase> EntityList = GetEntities();
-
-            foreach (EntityBase ent in EntityList)
+            EntityBase[] entityList = GetEntities();
+            foreach (EntityBase ent in entityList)
             {
                 if (ent is SceneObjectGroup)
                 {
@@ -259,7 +257,7 @@ namespace OpenSim.Region.Framework.Scenes
 
         public virtual void ProcessObjectGrab(uint localID, Vector3 offsetPos, IClientAPI remoteClient, List<SurfaceTouchEventArgs> surfaceArgs)
         {
-            List<EntityBase> EntityList = GetEntities();
+            EntityBase[] EntityList = GetEntities();
 
             SurfaceTouchEventArgs surfaceArg = null;
             if (surfaceArgs != null && surfaceArgs.Count > 0)
@@ -303,7 +301,7 @@ namespace OpenSim.Region.Framework.Scenes
 
         public virtual void ProcessObjectGrabUpdate(UUID objectID, Vector3 offset, Vector3 pos, IClientAPI remoteClient, List<SurfaceTouchEventArgs> surfaceArgs)
         {
-            List<EntityBase> EntityList = GetEntities();
+            EntityBase[] EntityList = GetEntities();
 
             SurfaceTouchEventArgs surfaceArg = null;
             if (surfaceArgs != null && surfaceArgs.Count > 0)
@@ -343,7 +341,7 @@ namespace OpenSim.Region.Framework.Scenes
 
         public virtual void ProcessObjectDeGrab(uint localID, IClientAPI remoteClient, List<SurfaceTouchEventArgs> surfaceArgs)
         {
-            List<EntityBase> EntityList = GetEntities();
+            EntityBase[] EntityList = GetEntities();
 
             SurfaceTouchEventArgs surfaceArg = null;
             if (surfaceArgs != null && surfaceArgs.Count > 0)
diff --git a/OpenSim/Region/Framework/Scenes/Scene.cs b/OpenSim/Region/Framework/Scenes/Scene.cs
index 82e7d76..7ce95a7 100644
--- a/OpenSim/Region/Framework/Scenes/Scene.cs
+++ b/OpenSim/Region/Framework/Scenes/Scene.cs
@@ -1029,29 +1029,30 @@ namespace OpenSim.Region.Framework.Scenes
                 if (ScriptEngine)
                 {
                     m_log.Info("Stopping all Scripts in Scene");
-                    foreach (EntityBase ent in Entities)
+                    
+                    EntityBase[] entities = Entities.GetEntities();
+                    foreach (EntityBase ent in entities)
                     {
                         if (ent is SceneObjectGroup)
-                        {
-                            ((SceneObjectGroup) ent).RemoveScriptInstances(false);
-                        }
+                            ((SceneObjectGroup)ent).RemoveScriptInstances(false);
                     }
                 }
                 else
                 {
                     m_log.Info("Starting all Scripts in Scene");
-                    lock (Entities)
+
+                    EntityBase[] entities = Entities.GetEntities();
+                    foreach (EntityBase ent in entities)
                     {
-                        foreach (EntityBase ent in Entities)
+                        if (ent is SceneObjectGroup)
                         {
-                            if (ent is SceneObjectGroup)
-                            {
-                                ((SceneObjectGroup)ent).CreateScriptInstances(0, false, DefaultScriptEngine, 0);
-                                ((SceneObjectGroup)ent).ResumeScripts();
-                            }
+                            SceneObjectGroup sog = (SceneObjectGroup)ent;
+                            sog.CreateScriptInstances(0, false, DefaultScriptEngine, 0);
+                            sog.ResumeScripts();
                         }
                     }
                 }
+
                 m_scripts_enabled = !ScriptEngine;
                 m_log.Info("[TOTEDD]: Here is the method to trigger disabling of the scripting engine");
             }
@@ -1098,7 +1099,7 @@ namespace OpenSim.Region.Framework.Scenes
             shuttingdown = true;
 
             m_log.Debug("[SCENE]: Persisting changed objects");
-            List<EntityBase> entities = GetEntities();
+            EntityBase[] entities = GetEntities();
             foreach (EntityBase entity in entities)
             {
                 if (!entity.IsDeleted && entity is SceneObjectGroup && ((SceneObjectGroup)entity).HasGroupChanged)
@@ -2037,8 +2038,7 @@ namespace OpenSim.Region.Framework.Scenes
         {
             lock (Entities)
             {
-                ICollection<EntityBase> entities = new List<EntityBase>(Entities);
-
+                EntityBase[] entities = Entities.GetEntities();
                 foreach (EntityBase e in entities)
                 {
                     if (e is SceneObjectGroup)
@@ -3977,9 +3977,8 @@ namespace OpenSim.Region.Framework.Scenes
         /// </summary>
         public void ForceClientUpdate()
         {
-            List<EntityBase> EntityList = GetEntities();
-
-            foreach (EntityBase ent in EntityList)
+            EntityBase[] entityList = GetEntities();
+            foreach (EntityBase ent in entityList)
             {
                 if (ent is SceneObjectGroup)
                 {
@@ -3997,9 +3996,8 @@ namespace OpenSim.Region.Framework.Scenes
         {
             m_log.Debug("Searching for Primitive: '" + cmdparams[2] + "'");
 
-            List<EntityBase> EntityList = GetEntities();
-
-            foreach (EntityBase ent in EntityList)
+            EntityBase[] entityList = GetEntities();
+            foreach (EntityBase ent in entityList)
             {
                 if (ent is SceneObjectGroup)
                 {
@@ -4368,7 +4366,7 @@ namespace OpenSim.Region.Framework.Scenes
         /// will not affect the original list of objects in the scene.
         /// </summary>
         /// <returns></returns>
-        public List<EntityBase> GetEntities()
+        public EntityBase[] GetEntities()
         {
             return m_sceneGraph.GetEntities();
         }
@@ -4402,9 +4400,8 @@ namespace OpenSim.Region.Framework.Scenes
 
         public void CleanTempObjects()
         {
-            List<EntityBase> objs = GetEntities();
-
-            foreach (EntityBase obj in objs)
+            EntityBase[] entities = GetEntities();
+            foreach (EntityBase obj in entities)
             {
                 if (obj is SceneObjectGroup)
                 {
diff --git a/OpenSim/Region/Framework/Scenes/SceneGraph.cs b/OpenSim/Region/Framework/Scenes/SceneGraph.cs
index dfb26b9..3d3e822 100644
--- a/OpenSim/Region/Framework/Scenes/SceneGraph.cs
+++ b/OpenSim/Region/Framework/Scenes/SceneGraph.cs
@@ -348,68 +348,57 @@ namespace OpenSim.Region.Framework.Scenes
             if (sceneObject == null || sceneObject.RootPart == null || sceneObject.RootPart.UUID == UUID.Zero)
                 return false;
 
-            lock (sceneObject)
-            {            
-                if (Entities.ContainsKey(sceneObject.UUID))
-                {
-//                    m_log.WarnFormat(
-//                        "[SCENE GRAPH]: Scene object {0} {1} was already in region {2} on add request", 
-//                        sceneObject.Name, sceneObject.UUID, m_parentScene.RegionInfo.RegionName);                    
-                    return false;
-                }
-                   
-//                    m_log.DebugFormat(
-//                        "[SCENE GRAPH]: Adding object {0} {1} to region {2}", 
-//                        sceneObject.Name, sceneObject.UUID, m_parentScene.RegionInfo.RegionName);                
-            
-                lock (sceneObject.Children)
+            if (Entities.ContainsKey(sceneObject.UUID))
+                return false;
+
+            // Clamp child prim sizes and add child prims to the m_numPrim count
+            lock (sceneObject.Children)
+            {
+                if (m_parentScene.m_clampPrimSize)
                 {
-                    if (m_parentScene.m_clampPrimSize)
+                    foreach (SceneObjectPart part in sceneObject.Children.Values)
                     {
-                        foreach (SceneObjectPart part in sceneObject.Children.Values)
-                        {
-                            Vector3 scale = part.Shape.Scale;
-        
-                            if (scale.X > m_parentScene.m_maxNonphys)
-                                scale.X = m_parentScene.m_maxNonphys;
-                            if (scale.Y > m_parentScene.m_maxNonphys)
-                                scale.Y = m_parentScene.m_maxNonphys;
-                            if (scale.Z > m_parentScene.m_maxNonphys)
-                                scale.Z = m_parentScene.m_maxNonphys;
-        
-                            part.Shape.Scale = scale;
-                        }
+                        Vector3 scale = part.Shape.Scale;
+
+                        if (scale.X > m_parentScene.m_maxNonphys)
+                            scale.X = m_parentScene.m_maxNonphys;
+                        if (scale.Y > m_parentScene.m_maxNonphys)
+                            scale.Y = m_parentScene.m_maxNonphys;
+                        if (scale.Z > m_parentScene.m_maxNonphys)
+                            scale.Z = m_parentScene.m_maxNonphys;
+
+                        part.Shape.Scale = scale;
                     }
-                    
-                    m_numPrim += sceneObject.Children.Count;
                 }
-        
-                sceneObject.AttachToScene(m_parentScene);
 
-                if (sendClientUpdates)
-                    sceneObject.ScheduleGroupForFullUpdate();
-                                 
-                Entities.Add(sceneObject);                    
+                m_numPrim += sceneObject.Children.Count;
+            }
 
-                if (attachToBackup)
-                    sceneObject.AttachToBackup();
+            sceneObject.AttachToScene(m_parentScene);
 
-                if (OnObjectCreate != null)
-                    OnObjectCreate(sceneObject);
-                
-                lock (SceneObjectGroupsByFullID)
-                {
-                    SceneObjectGroupsByFullID[sceneObject.UUID] = sceneObject;
-                    foreach (SceneObjectPart part in sceneObject.Children.Values)
-                        SceneObjectGroupsByFullID[part.UUID] = sceneObject;
-                }
-                    
-                lock (SceneObjectGroupsByLocalID)
-                {
-                    SceneObjectGroupsByLocalID[sceneObject.LocalId] = sceneObject;
-                    foreach (SceneObjectPart part in sceneObject.Children.Values)
-                        SceneObjectGroupsByLocalID[part.LocalId] = sceneObject;
-                }
+            if (sendClientUpdates)
+                sceneObject.ScheduleGroupForFullUpdate();
+
+            Entities.Add(sceneObject);
+
+            if (attachToBackup)
+                sceneObject.AttachToBackup();
+
+            if (OnObjectCreate != null)
+                OnObjectCreate(sceneObject);
+
+            lock (SceneObjectGroupsByFullID)
+            {
+                SceneObjectGroupsByFullID[sceneObject.UUID] = sceneObject;
+                foreach (SceneObjectPart part in sceneObject.Children.Values)
+                    SceneObjectGroupsByFullID[part.UUID] = sceneObject;
+            }
+
+            lock (SceneObjectGroupsByLocalID)
+            {
+                SceneObjectGroupsByLocalID[sceneObject.LocalId] = sceneObject;
+                foreach (SceneObjectPart part in sceneObject.Children.Values)
+                    SceneObjectGroupsByLocalID[part.LocalId] = sceneObject;
             }
 
             return true;
@@ -421,42 +410,38 @@ namespace OpenSim.Region.Framework.Scenes
         /// <returns>true if the object was deleted, false if there was no object to delete</returns>
         public bool DeleteSceneObject(UUID uuid, bool resultOfObjectLinked)
         {
-            if (Entities.ContainsKey(uuid))
-            {
-                SceneObjectGroup grp = (SceneObjectGroup)Entities[uuid];
+            EntityBase entity;
+            if (!Entities.TryGetValue(uuid, out entity) && entity is SceneObjectGroup)
+                return false;
 
-                if (!resultOfObjectLinked)
-                {
-                    m_numPrim -= grp.PrimCount;
+            SceneObjectGroup grp = (SceneObjectGroup)entity;
 
-                    if ((grp.RootPart.Flags & PrimFlags.Physics) == PrimFlags.Physics)
-                        RemovePhysicalPrim(grp.PrimCount);
-                }
+            if (!resultOfObjectLinked)
+            {
+                m_numPrim -= grp.PrimCount;
 
-                if (OnObjectRemove != null)
-                    OnObjectRemove(Entities[uuid]);
+                if ((grp.RootPart.Flags & PrimFlags.Physics) == PrimFlags.Physics)
+                    RemovePhysicalPrim(grp.PrimCount);
+            }
 
-                lock (SceneObjectGroupsByFullID)
-                {
-                    foreach (SceneObjectPart part in grp.Children.Values)
-                        SceneObjectGroupsByFullID.Remove(part.UUID);
-                    SceneObjectGroupsByFullID.Remove(grp.RootPart.UUID);
-                }
-                lock (SceneObjectGroupsByLocalID)
-                {
-                    foreach (SceneObjectPart part in grp.Children.Values)
-                        SceneObjectGroupsByLocalID.Remove(part.LocalId);
-                    SceneObjectGroupsByLocalID.Remove(grp.RootPart.LocalId);
-                }
+            if (OnObjectRemove != null)
+                OnObjectRemove(Entities[uuid]);
 
-                Entities.Remove(uuid);
-                //SceneObjectGroup part;
-                //((part.RootPart.Flags & PrimFlags.Physics) == PrimFlags.Physics)
+            lock (SceneObjectGroupsByFullID)
+            {
+                foreach (SceneObjectPart part in grp.Children.Values)
+                    SceneObjectGroupsByFullID.Remove(part.UUID);
+                SceneObjectGroupsByFullID.Remove(grp.RootPart.UUID);
+            }
 
-                return true;
+            lock (SceneObjectGroupsByLocalID)
+            {
+                foreach (SceneObjectPart part in grp.Children.Values)
+                    SceneObjectGroupsByLocalID.Remove(part.LocalId);
+                SceneObjectGroupsByLocalID.Remove(grp.RootPart.LocalId);
             }
 
-            return false;
+            return Entities.Remove(uuid);
         }
 
         /// <summary>
@@ -468,9 +453,7 @@ namespace OpenSim.Region.Framework.Scenes
         protected internal void AddToUpdateList(SceneObjectGroup obj)
         {
             lock (m_updateList)
-            {
                 m_updateList[obj.UUID] = obj;
-            }
         }
 
         /// <summary>
@@ -480,34 +463,39 @@ namespace OpenSim.Region.Framework.Scenes
         {
             if (!Monitor.TryEnter(m_updateLock))
                 return;
-
-            List<SceneObjectGroup> updates;
-
-            // Some updates add more updates to the updateList. 
-            // Get the current list of updates and clear the list before iterating
-            lock (m_updateList)
-            {
-                updates = new List<SceneObjectGroup>(m_updateList.Values);
-                m_updateList.Clear();
-            }
-
-            // Go through all updates
-            for (int i = 0; i < updates.Count; i++)
+            try
             {
-                SceneObjectGroup sog = updates[i];
+                List<SceneObjectGroup> updates;
 
-                // Don't abort the whole update if one entity happens to give us an exception.
-                try
+                // Some updates add more updates to the updateList. 
+                // Get the current list of updates and clear the list before iterating
+                lock (m_updateList)
                 {
-                    sog.Update();
+                    updates = new List<SceneObjectGroup>(m_updateList.Values);
+                    m_updateList.Clear();
                 }
-                catch (Exception e)
+
+                // Go through all updates
+                for (int i = 0; i < updates.Count; i++)
                 {
-                    m_log.ErrorFormat(
-                        "[INNER SCENE]: Failed to update {0}, {1} - {2}", sog.Name, sog.UUID, e);
+                    SceneObjectGroup sog = updates[i];
+
+                    // Don't abort the whole update if one entity happens to give us an exception.
+                    try
+                    {
+                        sog.Update();
+                    }
+                    catch (Exception e)
+                    {
+                        m_log.ErrorFormat(
+                            "[INNER SCENE]: Failed to update {0}, {1} - {2}", sog.Name, sog.UUID, e);
+                    }
                 }
             }
-            Monitor.Exit(m_updateLock);
+            finally
+            {
+                Monitor.Exit(m_updateLock);
+            }
         }
 
         protected internal void AddPhysicalPrim(int number)
@@ -864,8 +852,9 @@ namespace OpenSim.Region.Framework.Scenes
         /// <returns>null if no scene object group containing that prim is found</returns>
         public SceneObjectGroup GetGroupByPrim(uint localID)
         {
-            if (Entities.ContainsKey(localID))
-                return Entities[localID] as SceneObjectGroup;
+            EntityBase entity;
+            if (Entities.TryGetValue(localID, out entity))
+                return entity as SceneObjectGroup;
 
             //m_log.DebugFormat("Entered GetGroupByPrim with localID {0}", localID);
             SceneObjectGroup sog;
@@ -879,23 +868,22 @@ namespace OpenSim.Region.Framework.Scenes
                 }
             }
 
-            List<EntityBase> EntityList = GetEntities();
-            foreach (EntityBase ent in EntityList)
+            EntityBase[] entityList = GetEntities();
+            foreach (EntityBase ent in entityList)
             {
                 //m_log.DebugFormat("Looking at entity {0}", ent.UUID);
                 if (ent is SceneObjectGroup)
                 {
-                    if (((SceneObjectGroup)ent).HasChildPrim(localID))
+                    sog = (SceneObjectGroup)ent;
+                    if (sog.HasChildPrim(localID))
                     {
-                        sog = (SceneObjectGroup)ent;
                         lock (SceneObjectGroupsByLocalID)
-                        {
                             SceneObjectGroupsByLocalID[localID] = sog;
-                        }
                         return sog;
                     }
                 }
             }
+
             return null;
         }
 
@@ -921,23 +909,21 @@ namespace OpenSim.Region.Framework.Scenes
                 }
             }
 
-            List<EntityBase> EntityList = GetEntities();
-
-            foreach (EntityBase ent in EntityList)
+            EntityBase[] entityList = GetEntities();
+            foreach (EntityBase ent in entityList)
             {
                 if (ent is SceneObjectGroup)
                 {
-                    if (((SceneObjectGroup)ent).HasChildPrim(fullID))
+                    sog = (SceneObjectGroup)ent;
+                    if (sog.HasChildPrim(fullID))
                     {
-                        sog = (SceneObjectGroup)ent;
                         lock (SceneObjectGroupsByFullID)
-                        {
                             SceneObjectGroupsByFullID[fullID] = sog;
-                        }
                         return sog;
                     }
                 }
             }
+
             return null;
         }
 
@@ -946,7 +932,7 @@ namespace OpenSim.Region.Framework.Scenes
             // Primitive Ray Tracing
             float closestDistance = 280f;
             EntityIntersection result = new EntityIntersection();
-            List<EntityBase> EntityList = GetEntities();
+            EntityBase[] EntityList = GetEntities();
             foreach (EntityBase ent in EntityList)
             {
                 if (ent is SceneObjectGroup)
@@ -984,23 +970,28 @@ namespace OpenSim.Region.Framework.Scenes
         /// <returns>null if the part was not found</returns>
         protected internal SceneObjectPart GetSceneObjectPart(string name)
         {
-            List<EntityBase> EntityList = GetEntities();
+            SceneObjectPart sop = null;
 
-            // FIXME: use a dictionary here
-            foreach (EntityBase ent in EntityList)
-            {
-                if (ent is SceneObjectGroup)
+            Entities.Find(
+                delegate(EntityBase entity)
                 {
-                    foreach (SceneObjectPart p in ((SceneObjectGroup) ent).GetParts())
+                    if (entity is SceneObjectGroup)
                     {
-                        if (p.Name == name)
+                        foreach (SceneObjectPart p in ((SceneObjectGroup)entity).GetParts())
                         {
-                            return p;
+                            if (p.Name == name)
+                            {
+                                sop = p;
+                                return true;
+                            }
                         }
                     }
+
+                    return false;
                 }
-            }
-            return null;
+            );
+
+            return sop;
         }
 
         /// <summary>
@@ -1021,7 +1012,7 @@ namespace OpenSim.Region.Framework.Scenes
         /// it
         /// </summary>
         /// <returns></returns>
-        protected internal List<EntityBase> GetEntities()
+        protected internal EntityBase[] GetEntities()
         {
             return Entities.GetEntities();
         }
@@ -1030,7 +1021,7 @@ namespace OpenSim.Region.Framework.Scenes
         {
             Dictionary<uint, float> topScripts = new Dictionary<uint, float>();
 
-            List<EntityBase> EntityList = GetEntities();
+            EntityBase[] EntityList = GetEntities();
             int limit = 0;
             foreach (EntityBase ent in EntityList)
             {
@@ -1726,8 +1717,8 @@ namespace OpenSim.Region.Framework.Scenes
             UUID objid = UUID.Zero;
             SceneObjectPart obj = null;
 
-            List<EntityBase> EntityList = GetEntities();
-            foreach (EntityBase ent in EntityList)
+            EntityBase[] entityList = GetEntities();
+            foreach (EntityBase ent in entityList)
             {
                 if (ent is SceneObjectGroup)
                 {
diff --git a/OpenSim/Region/Framework/Scenes/SceneViewer.cs b/OpenSim/Region/Framework/Scenes/SceneViewer.cs
index f478a4a..7aa5a93 100644
--- a/OpenSim/Region/Framework/Scenes/SceneViewer.cs
+++ b/OpenSim/Region/Framework/Scenes/SceneViewer.cs
@@ -75,7 +75,8 @@ namespace OpenSim.Region.Framework.Scenes
 
                     lock(m_pendingObjects)
                     {
-                        foreach (EntityBase e in m_presence.Scene.Entities)
+                        EntityBase[] entities = m_presence.Scene.Entities.GetEntities();
+                        foreach (EntityBase e in entities)
                         {
                             if (e != null && e is SceneObjectGroup)
                                 m_pendingObjects.Enqueue((SceneObjectGroup)e);
diff --git a/OpenSim/Region/Framework/Scenes/Serialization/SceneXmlLoader.cs b/OpenSim/Region/Framework/Scenes/Serialization/SceneXmlLoader.cs
index b6677f0..5494549 100644
--- a/OpenSim/Region/Framework/Scenes/Serialization/SceneXmlLoader.cs
+++ b/OpenSim/Region/Framework/Scenes/Serialization/SceneXmlLoader.cs
@@ -84,9 +84,8 @@ namespace OpenSim.Region.Framework.Scenes.Serialization
             int primCount = 0;
             stream.WriteLine("<scene>\n");
 
-            List<EntityBase> EntityList = scene.GetEntities();
-
-            foreach (EntityBase ent in EntityList)
+            EntityBase[] entityList = scene.GetEntities();
+            foreach (EntityBase ent in entityList)
             {
                 if (ent is SceneObjectGroup)
                 {
@@ -204,16 +203,14 @@ namespace OpenSim.Region.Framework.Scenes.Serialization
 
         public static void SavePrimsToXml2(Scene scene, string fileName)
         {
-            List<EntityBase> EntityList = scene.GetEntities();
-
-            SavePrimListToXml2(EntityList, fileName);
+            EntityBase[] entityList = scene.GetEntities();
+            SavePrimListToXml2(entityList, fileName);
         }
 
         public static void SavePrimsToXml2(Scene scene, TextWriter stream, Vector3 min, Vector3 max)
         {
-            List<EntityBase> EntityList = scene.GetEntities();
-
-            SavePrimListToXml2(EntityList, stream, min, max);
+            EntityBase[] entityList = scene.GetEntities();
+            SavePrimListToXml2(entityList, stream, min, max);
         }
         
         public static void SaveNamedPrimsToXml2(Scene scene, string primName, string fileName)
@@ -222,7 +219,7 @@ namespace OpenSim.Region.Framework.Scenes.Serialization
                 "[SERIALISER]: Saving prims with name {0} in xml2 format for region {1} to {2}", 
                 primName, scene.RegionInfo.RegionName, fileName);
 
-            List<EntityBase> entityList = scene.GetEntities();
+            EntityBase[] entityList = scene.GetEntities();
             List<EntityBase> primList = new List<EntityBase>();
 
             foreach (EntityBase ent in entityList)
@@ -236,10 +233,10 @@ namespace OpenSim.Region.Framework.Scenes.Serialization
                 }
             }
 
-            SavePrimListToXml2(primList, fileName);
+            SavePrimListToXml2(primList.ToArray(), fileName);
         }
 
-        public static void SavePrimListToXml2(List<EntityBase> entityList, string fileName)
+        public static void SavePrimListToXml2(EntityBase[] entityList, string fileName)
         {
             FileStream file = new FileStream(fileName, FileMode.Create);
             try
@@ -260,7 +257,7 @@ namespace OpenSim.Region.Framework.Scenes.Serialization
             }
         }
 
-        public static void SavePrimListToXml2(List<EntityBase> entityList, TextWriter stream, Vector3 min, Vector3 max)
+        public static void SavePrimListToXml2(EntityBase[] entityList, TextWriter stream, Vector3 min, Vector3 max)
         {
             int primCount = 0;
             stream.WriteLine("<scene>\n");
diff --git a/OpenSim/Region/OptionalModules/Agent/InternetRelayClientView/Server/IRCClientView.cs b/OpenSim/Region/OptionalModules/Agent/InternetRelayClientView/Server/IRCClientView.cs
index 6793ef6..159af79 100644
--- a/OpenSim/Region/OptionalModules/Agent/InternetRelayClientView/Server/IRCClientView.cs
+++ b/OpenSim/Region/OptionalModules/Agent/InternetRelayClientView/Server/IRCClientView.cs
@@ -375,8 +375,7 @@ namespace OpenSim.Region.OptionalModules.Agent.InternetRelayClientView.Server
 
         private void IRC_SendNamesReply()
         {
-            List<EntityBase> users = m_scene.Entities.GetAllByType<ScenePresence>();
-
+            EntityBase[] users = m_scene.Entities.GetAllByType<ScenePresence>();
             foreach (EntityBase user in users)
             {
                 SendServerCommand("353 " + m_nick + " = " + IrcRegionName + " :" + user.Name.Replace(" ", ""));
@@ -386,8 +385,7 @@ namespace OpenSim.Region.OptionalModules.Agent.InternetRelayClientView.Server
 
         private void IRC_SendWhoReply()
         {
-            List<EntityBase> users = m_scene.Entities.GetAllByType<ScenePresence>();
-
+            EntityBase[] users = m_scene.Entities.GetAllByType<ScenePresence>();
             foreach (EntityBase user in users)
             {
                 /*SendServerCommand(String.Format("352 {0} {1} {2} {3} {4} {5} :0 {6}", IrcRegionName,
@@ -415,11 +413,11 @@ namespace OpenSim.Region.OptionalModules.Agent.InternetRelayClientView.Server
 
         private void IRC_SendReplyUsers()
         {
-            List<EntityBase> users = m_scene.Entities.GetAllByType<ScenePresence>();
+            EntityBase[] users = m_scene.Entities.GetAllByType<ScenePresence>();
 
             SendServerCommand("392 :UserID   Terminal  Host");
 
-            if (users.Count == 0)
+            if (users.Length == 0)
             {
                 SendServerCommand("395 :Nobody logged in");
                 return;
diff --git a/OpenSim/Region/OptionalModules/ContentManagementSystem/CMEntityCollection.cs b/OpenSim/Region/OptionalModules/ContentManagementSystem/CMEntityCollection.cs
index de1e01c..d21b652 100644
--- a/OpenSim/Region/OptionalModules/ContentManagementSystem/CMEntityCollection.cs
+++ b/OpenSim/Region/OptionalModules/ContentManagementSystem/CMEntityCollection.cs
@@ -111,7 +111,7 @@ namespace OpenSim.Region.OptionalModules.ContentManagement
         }
 
         // Check if there are SceneObjectGroups in the list that do not have corresponding ContentManagementGroups in the CMEntityHash
-        public System.Collections.ArrayList CheckForMissingEntities(System.Collections.Generic.List<EntityBase> currList)
+        public System.Collections.ArrayList CheckForMissingEntities(EntityBase[] currList)
         {
             System.Collections.ArrayList missingList = new System.Collections.ArrayList();
             SceneObjectGroup temp = null;
diff --git a/OpenSim/Region/OptionalModules/ContentManagementSystem/ContentManagementEntity.cs b/OpenSim/Region/OptionalModules/ContentManagementSystem/ContentManagementEntity.cs
index 2730eee..49d20e1 100644
--- a/OpenSim/Region/OptionalModules/ContentManagementSystem/ContentManagementEntity.cs
+++ b/OpenSim/Region/OptionalModules/ContentManagementSystem/ContentManagementEntity.cs
@@ -127,7 +127,7 @@ namespace OpenSim.Region.OptionalModules.ContentManagement
         /// </summary>
         public void FindDifferences()
         {
-            System.Collections.Generic.List<EntityBase> sceneEntityList = m_Entity.Scene.GetEntities();
+            List<EntityBase> sceneEntityList = new List<EntityBase>(m_Entity.Scene.GetEntities());
             DiffersFromSceneGroup = false;
             // if group is not contained in scene's list
             if (!ContainsKey(sceneEntityList, m_UnchangedEntity.UUID))
diff --git a/OpenSim/Region/OptionalModules/Scripting/Minimodule/ObjectAccessor.cs b/OpenSim/Region/OptionalModules/Scripting/Minimodule/ObjectAccessor.cs
index 6ba5ccf..140264b 100644
--- a/OpenSim/Region/OptionalModules/Scripting/Minimodule/ObjectAccessor.cs
+++ b/OpenSim/Region/OptionalModules/Scripting/Minimodule/ObjectAccessor.cs
@@ -41,12 +41,14 @@ namespace OpenSim.Region.OptionalModules.Scripting.Minimodule
         private readonly Scene m_scene;
         private readonly IEnumerator<EntityBase> m_sogEnum;
         private readonly ISecurityCredential m_security;
+        private readonly List<EntityBase> m_entities;
 
         public IObjEnum(Scene scene, ISecurityCredential security)
         {
             m_scene = scene;
             m_security = security;
-            m_sogEnum = m_scene.Entities.GetAllByType<SceneObjectGroup>().GetEnumerator();
+            m_entities = new List<EntityBase>(m_scene.Entities.GetEntities());
+            m_sogEnum = m_entities.GetEnumerator();
         }
 
         public void Dispose()
diff --git a/OpenSim/Region/OptionalModules/Scripting/Minimodule/World.cs b/OpenSim/Region/OptionalModules/Scripting/Minimodule/World.cs
index 45bb005..f2324d2 100644
--- a/OpenSim/Region/OptionalModules/Scripting/Minimodule/World.cs
+++ b/OpenSim/Region/OptionalModules/Scripting/Minimodule/World.cs
@@ -205,10 +205,10 @@ namespace OpenSim.Region.OptionalModules.Scripting.Minimodule
         {
             get
             {
-                List<EntityBase> ents = m_internalScene.Entities.GetAllByType<ScenePresence>();
-                IAvatar[] rets = new IAvatar[ents.Count];
+                EntityBase[] ents = m_internalScene.Entities.GetAllByType<ScenePresence>();
+                IAvatar[] rets = new IAvatar[ents.Length];
 
-                for (int i = 0; i < ents.Count; i++)
+                for (int i = 0; i < ents.Length; i++)
                 {
                     EntityBase ent = ents[i];
                     rets[i] = new SPAvatar(m_internalScene, ent.UUID, m_security);
diff --git a/OpenSim/Region/OptionalModules/World/TreePopulator/TreePopulatorModule.cs b/OpenSim/Region/OptionalModules/World/TreePopulator/TreePopulatorModule.cs
index 3ed338b..421da36 100644
--- a/OpenSim/Region/OptionalModules/World/TreePopulator/TreePopulatorModule.cs
+++ b/OpenSim/Region/OptionalModules/World/TreePopulator/TreePopulatorModule.cs
@@ -568,8 +568,7 @@ namespace OpenSim.Region.OptionalModules.World.TreePopulator
         {
             m_copse = new List<Copse>();
 
-            List<EntityBase> objs = m_scene.GetEntities();
-
+            EntityBase[] objs = m_scene.GetEntities();
             foreach (EntityBase obj in objs)
             {
                 if (obj is SceneObjectGroup)
diff --git a/OpenSim/Region/ScriptEngine/Shared/Api/Implementation/Plugins/SensorRepeat.cs b/OpenSim/Region/ScriptEngine/Shared/Api/Implementation/Plugins/SensorRepeat.cs
index 5c2abd5..2b67e84 100644
--- a/OpenSim/Region/ScriptEngine/Shared/Api/Implementation/Plugins/SensorRepeat.cs
+++ b/OpenSim/Region/ScriptEngine/Shared/Api/Implementation/Plugins/SensorRepeat.cs
@@ -286,7 +286,7 @@ namespace OpenSim.Region.ScriptEngine.Shared.Api.Plugins
             }
             else
             {
-                Entities = m_CmdManager.m_ScriptEngine.World.GetEntities();
+                Entities = new List<EntityBase>(m_CmdManager.m_ScriptEngine.World.GetEntities());
             }
             SceneObjectPart SensePoint = ts.host;