Inconsistent locking of ScenePresence array in SceneGraph. Fixed by eliminating option to return the actual list. Callers can now either request a copy of the array as a new List or ask the SceneGraph to call a delegate function on every ScenePresence. Iteration and locking of the ScenePresences now takes place only within the SceneGraph class.

This patch also applies a fix to Combat/CombatModule.cs which had unlocked iteration of the ScenePresences and inconsistent try/catch around the use of those ScenePresences.

10 files changed, 258 insertions, 233 deletions

diff --git a/OpenSim/Region/CoreModules/Avatar/Combat/CombatModule.cs b/OpenSim/Region/CoreModules/Avatar/Combat/CombatModule.cs
index 3614915..9df6074 100644
--- a/OpenSim/Region/CoreModules/Avatar/Combat/CombatModule.cs
+++ b/OpenSim/Region/CoreModules/Avatar/Combat/CombatModule.cs
@@ -89,60 +89,57 @@ namespace OpenSim.Region.CoreModules.Avatar.Combat.CombatModule
             get { return true; }
         }
 
-        private void KillAvatar(uint killerObjectLocalID, ScenePresence DeadAvatar)
+        private void KillAvatar(uint killerObjectLocalID, ScenePresence deadAvatar)
         {
+            string deadAvatarMessage;
+            ScenePresence killingAvatar = null;
+            string killingAvatarMessage;
+
             if (killerObjectLocalID == 0)
-                DeadAvatar.ControllingClient.SendAgentAlertMessage("You committed suicide!", true);
+                deadAvatarMessage = "You committed suicide!";
             else
             {
-                bool foundResult = false;
-                string resultstring = String.Empty;
-                ScenePresence[] allav = DeadAvatar.Scene.GetScenePresences();
-                try
+                // Try to get the avatar responsible for the killing
+                killingAvatar = deadAvatar.Scene.GetScenePresence(killerObjectLocalID);
+                if (killingAvatar == null)
                 {
-                    for (int i = 0; i < allav.Length; i++)
+                    // Try to get the object which was responsible for the killing
+                    SceneObjectPart part = deadAvatar.Scene.GetSceneObjectPart(killerObjectLocalID);
+                    if (part == null)
                     {
-                        ScenePresence av = allav[i];
-
-                        if (av.LocalId == killerObjectLocalID)
-                        {
-                            av.ControllingClient.SendAlertMessage("You fragged " + DeadAvatar.Firstname + " " + DeadAvatar.Lastname);
-                            resultstring = av.Firstname + " " + av.Lastname;
-                            foundResult = true;
-                        }
+                        // Cause of death: Unknown
+                        deadAvatarMessage = "You died!";
                     }
-                } catch (InvalidOperationException)
-                {
-
-                }
-
-                if (!foundResult)
-                {
-                    SceneObjectPart part = DeadAvatar.Scene.GetSceneObjectPart(killerObjectLocalID);
-                    if (part != null)
+                    else
                     {
-                        ScenePresence av = DeadAvatar.Scene.GetScenePresence(part.OwnerID);
-                        if (av != null)
-                        {
-                            av.ControllingClient.SendAlertMessage("You fragged " + DeadAvatar.Firstname + " " + DeadAvatar.Lastname);
-                            resultstring = av.Firstname + " " + av.Lastname;
-                            DeadAvatar.ControllingClient.SendAgentAlertMessage("You got killed by " + resultstring + "!", true);
-                        }
+                        // Try to find the avatar wielding the killing object
+                        killingAvatar = deadAvatar.Scene.GetScenePresence(part.OwnerID);
+                        if (killingAvatar == null)
+                            deadAvatarMessage = String.Format("You impaled yourself on {0} owned by {1}!", part.Name, deadAvatar.Scene.GetUserName(part.OwnerID));
                         else
                         {
-                            string killer = DeadAvatar.Scene.GetUserName(part.OwnerID);
-                            DeadAvatar.ControllingClient.SendAgentAlertMessage("You impaled yourself on " + part.Name + " owned by " + killer +"!", true);
+                            killingAvatarMessage = String.Format("You fragged {0}!", deadAvatar.Name);
+                            deadAvatarMessage = String.Format("You got killed by {0}!", killingAvatar.Name);
                         }
-                        //DeadAvatar.Scene. part.ObjectOwner
-                    }
-                    else
-                    {
-                        DeadAvatar.ControllingClient.SendAgentAlertMessage("You died!", true);
                     }
                 }
+                else
+                {
+                    killingAvatarMessage = String.Format("You fragged {0}!", deadAvatar.Name);
+                    deadAvatarMessage = String.Format("You got killed by {0}!", killingAvatar.Name);
+                }
             }
-            DeadAvatar.Health = 100;
-            DeadAvatar.Scene.TeleportClientHome(DeadAvatar.UUID, DeadAvatar.ControllingClient);
+            try
+            {
+                deadAvatar.ControllingClient.SendAgentAlertMessage(deadAvatarMessage, true);
+                if(killingAvatar != null)
+                    killingAvatar.ControllingClient.SendAlertMessage("You fragged " + deadAvatar.Firstname + " " + deadAvatar.Lastname);
+            }
+            catch (InvalidOperationException)
+            { }
+
+            deadAvatar.Health = 100;
+            deadAvatar.Scene.TeleportClientHome(deadAvatar.UUID, deadAvatar.ControllingClient);
         }
 
         private void AvatarEnteringParcel(ScenePresence avatar, int localLandID, UUID regionID)
diff --git a/OpenSim/Region/CoreModules/Avatar/Dialog/DialogModule.cs b/OpenSim/Region/CoreModules/Avatar/Dialog/DialogModule.cs
index b8e013c..c31266c 100644
--- a/OpenSim/Region/CoreModules/Avatar/Dialog/DialogModule.cs
+++ b/OpenSim/Region/CoreModules/Avatar/Dialog/DialogModule.cs
@@ -87,31 +87,18 @@ namespace OpenSim.Region.CoreModules.Avatar.Dialog
         
         public void SendAlertToUser(string firstName, string lastName, string message, bool modal)
         {
-            ScenePresence[] presenceList = m_scene.GetScenePresences();
-
-            for (int i = 0; i < presenceList.Length; i++)
-            {
-                ScenePresence presence = presenceList[i];
-
-                if (presence.Firstname == firstName && presence.Lastname == lastName)
-                {
-                    presence.ControllingClient.SendAgentAlertMessage(message, modal);
-                    break;
-                }
-            }
+            ScenePresence presence = m_scene.GetScenePresence(firstName, lastName);
+            if(presence != null)
+                presence.ControllingClient.SendAgentAlertMessage(message, modal);
         }
         
         public void SendGeneralAlert(string message)
         {
-            ScenePresence[] presenceList = m_scene.GetScenePresences();
-
-            for (int i = 0; i < presenceList.Length; i++)
+            m_scene.ForEachScenePresence(delegate(ScenePresence presence)
             {
-                ScenePresence presence = presenceList[i];
-
                 if (!presence.IsChildAgent)
                     presence.ControllingClient.SendAlertMessage(message);
-            }
+            });
         }
 
         public void SendDialogToUser(
@@ -179,14 +166,11 @@ namespace OpenSim.Region.CoreModules.Avatar.Dialog
         public void SendNotificationToUsersInRegion(
             UUID fromAvatarID, string fromAvatarName, string message)
         {
-            ScenePresence[] presences = m_scene.GetScenePresences();
-
-            for (int i = 0; i < presences.Length; i++)
+            m_scene.ForEachScenePresence(delegate(ScenePresence presence)
             {
-                ScenePresence presence = presences[i];
                 if (!presence.IsChildAgent)
                     presence.ControllingClient.SendBlueBoxMessage(fromAvatarID, fromAvatarName, message);
-            }
+            });
         }
         
         /// <summary>
diff --git a/OpenSim/Region/CoreModules/World/Estate/EstateManagementModule.cs b/OpenSim/Region/CoreModules/World/Estate/EstateManagementModule.cs
index e3bab2d..464d922 100644
--- a/OpenSim/Region/CoreModules/World/Estate/EstateManagementModule.cs
+++ b/OpenSim/Region/CoreModules/World/Estate/EstateManagementModule.cs
@@ -469,12 +469,10 @@ namespace OpenSim.Region.CoreModules.World.Estate
         private void handleEstateTeleportAllUsersHomeRequest(IClientAPI remover_client, UUID invoice, UUID senderID)
         {
             // Get a fresh list that will not change as people get teleported away
-            ScenePresence[] presences = m_scene.GetScenePresences();
+            List<ScenePresence> presences = m_scene.GetScenePresences();
 
-            for (int i = 0; i < presences.Length; i++)
+            foreach(ScenePresence p in presences)
             {
-                ScenePresence p = presences[i];
-
                 if (p.UUID != senderID)
                 {
                     // make sure they are still there, we could be working down a long list
diff --git a/OpenSim/Region/Framework/Scenes/Scene.cs b/OpenSim/Region/Framework/Scenes/Scene.cs
index baa8759..a86a33c 100644
--- a/OpenSim/Region/Framework/Scenes/Scene.cs
+++ b/OpenSim/Region/Framework/Scenes/Scene.cs
@@ -3599,9 +3599,7 @@ namespace OpenSim.Region.Framework.Scenes
         public virtual void AgentCrossing(UUID agentID, Vector3 position, bool isFlying)
         {
             ScenePresence presence;
-            m_sceneGraph.TryGetAvatar(agentID, out presence);
-
-            if (presence != null)
+            if(m_sceneGraph.TryGetAvatar(agentID, out presence))
             {
                 try
                 {
@@ -3776,9 +3774,7 @@ namespace OpenSim.Region.Framework.Scenes
                                             Vector3 lookAt, uint teleportFlags)
         {
             ScenePresence sp;
-            m_sceneGraph.TryGetAvatar(remoteClient.AgentId, out sp);
-
-            if (sp != null)
+            if(m_sceneGraph.TryGetAvatar(remoteClient.AgentId, out sp))
             {
                 uint regionX = m_regInfo.RegionLocX;
                 uint regionY = m_regInfo.RegionLocY;
@@ -4134,6 +4130,11 @@ namespace OpenSim.Region.Framework.Scenes
 
         //The idea is to have a group of method that return a list of avatars meeting some requirement
         // ie it could be all m_scenePresences within a certain range of the calling prim/avatar.
+        // 
+        // GetAvatars returns a new list of all root agent presences in the scene
+        // GetScenePresences returns a new list of all presences in the scene or a filter may be passed.
+        // GetScenePresence returns the presence with matching UUID or first/last name.
+        // ForEachScenePresence requests the Scene to run a delegate function against all presences.
 
         /// <summary>
         /// Return a list of all avatars in this region.
@@ -4150,7 +4151,7 @@ namespace OpenSim.Region.Framework.Scenes
         /// This list is a new object, so it can be iterated over without locking.
         /// </summary>
         /// <returns></returns>
-        public ScenePresence[] GetScenePresences()
+        public List<ScenePresence> GetScenePresences()
         {
             return m_sceneGraph.GetScenePresences();
         }
@@ -4176,6 +4177,28 @@ namespace OpenSim.Region.Framework.Scenes
             return m_sceneGraph.GetScenePresence(avatarID);
         }
 
+        /// <summary>
+        /// Request the ScenePresence in this region by first/last name.
+        /// Should normally only be a single match, but first is always returned
+        /// </summary>
+        /// <param name="firstName"></param>
+        /// <param name="lastName"></param>
+        /// <returns></returns>
+        public ScenePresence GetScenePresence(string firstName, string lastName)
+        {
+            return m_sceneGraph.GetScenePresence(firstName, lastName);
+        }
+
+        /// <summary>
+        /// Request the ScenePresence in this region by localID.
+        /// </summary>
+        /// <param name="localID"></param>
+        /// <returns></returns>
+        public ScenePresence GetScenePresence(uint localID)
+        {
+            return m_sceneGraph.GetScenePresence(localID);
+        }
+
         public override bool PresenceChildStatus(UUID avatarID)
         {
             ScenePresence cp = GetScenePresence(avatarID);
@@ -4191,25 +4214,14 @@ namespace OpenSim.Region.Framework.Scenes
         }
 
         /// <summary>
-        ///
+        /// Performs action on all scene presences.
         /// </summary>
         /// <param name="action"></param>
         public void ForEachScenePresence(Action<ScenePresence> action)
         {
-            // We don't want to try to send messages if there are no avatars.
             if (m_sceneGraph != null)
             {
-                try
-                {
-                    ScenePresence[] presences = GetScenePresences();
-                    for (int i = 0; i < presences.Length; i++)
-                        action(presences[i]);
-                }
-                catch (Exception e)
-                {
-                    m_log.Info("[BUG] in " + RegionInfo.RegionName + ": " + e.ToString());
-                    m_log.Info("[BUG] Stack Trace: " + e.StackTrace);
-                }
+                m_sceneGraph.ForEachScenePresence(action);
             }
         }
 
diff --git a/OpenSim/Region/Framework/Scenes/SceneGraph.cs b/OpenSim/Region/Framework/Scenes/SceneGraph.cs
index d944834..d259c42 100644
--- a/OpenSim/Region/Framework/Scenes/SceneGraph.cs
+++ b/OpenSim/Region/Framework/Scenes/SceneGraph.cs
@@ -165,9 +165,10 @@ namespace OpenSim.Region.Framework.Scenes
 
         protected internal void UpdatePresences()
         {
-            ScenePresence[] updateScenePresences = GetScenePresences();
-            for (int i = 0; i < updateScenePresences.Length; i++)
-                updateScenePresences[i].Update();
+            ForEachScenePresence(delegate(ScenePresence presence)
+            {
+                presence.Update();
+            });
         }
 
         protected internal float UpdatePhysics(double elapsed)
@@ -196,9 +197,10 @@ namespace OpenSim.Region.Framework.Scenes
 
         protected internal void UpdateScenePresenceMovement()
         {
-            ScenePresence[] moveEntities = GetScenePresences();
-            for (int i = 0; i < moveEntities.Length; i++)
-                moveEntities[i].UpdateMovement();
+            ForEachScenePresence(delegate(ScenePresence presence)
+            {
+                presence.UpdateMovement();
+            });
         }
 
         #endregion
@@ -616,18 +618,16 @@ namespace OpenSim.Region.Framework.Scenes
 
         public void RecalculateStats()
         {
-            ScenePresence[] presences = GetScenePresences();
             int rootcount = 0;
             int childcount = 0;
 
-            for (int i = 0; i < presences.Length; i++)
+            ForEachScenePresence(delegate(ScenePresence presence)
             {
-                ScenePresence user = presences[i];
-                if (user.IsChildAgent)
+                if (presence.IsChildAgent)
                     ++childcount;
                 else
                     ++rootcount;
-            }
+            });
 
             m_numRootAgents = rootcount;
             m_numChildAgents = childcount;
@@ -674,25 +674,6 @@ namespace OpenSim.Region.Framework.Scenes
         #endregion
 
         #region Get Methods
-
-        /// <summary>
-        /// Request a List of all scene presences in this scene.  This is a new list, so no
-        /// locking is required to iterate over it.
-        /// </summary>
-        /// <returns></returns>
-        protected internal ScenePresence[] GetScenePresences()
-        {
-            return m_scenePresenceArray;
-        }
-
-        protected internal List<ScenePresence> GetAvatars()
-        {
-            List<ScenePresence> result =
-                GetScenePresences(delegate(ScenePresence scenePresence) { return !scenePresence.IsChildAgent; });
-
-            return result;
-        }
-
         /// <summary>
         /// Get the controlling client for the given avatar, if there is one.
         ///
@@ -718,45 +699,119 @@ namespace OpenSim.Region.Framework.Scenes
             return null;
         }
 
+        // The idea is to have a group of method that return a list of avatars meeting some requirement
+        // ie it could be all m_scenePresences within a certain range of the calling prim/avatar.
+        // 
+        // GetAvatars returns a new list of all root agent presences in the scene
+        // GetScenePresences returns a new list of all presences in the scene or a filter may be passed.
+        // GetScenePresence returns the presence with matching UUID or the first presence matching the passed filter.
+        // ForEachScenePresence requests the Scene to run a delegate function against all presences.
+
+        /// <summary>
+        /// Request a list of all avatars in this region (no child agents)
+        /// This list is a new object, so it can be iterated over without locking.
+        /// </summary>
+        /// <returns></returns>
+        public List<ScenePresence> GetAvatars()
+        {
+            return GetScenePresences(delegate(ScenePresence scenePresence)
+            {
+                return !scenePresence.IsChildAgent;
+            });
+        }
+
+        /// <summary>
+        /// Request a list of m_scenePresences in this World
+        /// Returns a copy so it can be iterated without a lock.
+        /// There is no guarantee that presences will remain in the scene after the list is returned.
+        /// </summary>
+        /// <returns></returns>
+        protected internal List<ScenePresence> GetScenePresences()
+        {
+            List<ScenePresence> result;
+            lock (m_scenePresences)
+            {
+                result = new List<ScenePresence>(m_scenePresenceArray.Length);
+                result.AddRange(m_scenePresenceArray);
+            }
+            return result;
+        }
+
         /// <summary>
         /// Request a filtered list of m_scenePresences in this World
+        /// Returns a copy so it can be iterated without a lock.
+        /// There is no guarantee that presences will remain in the scene after the list is returned.
         /// </summary>
         /// <returns></returns>
         protected internal List<ScenePresence> GetScenePresences(FilterAvatarList filter)
         {
-            // No locking of scene presences here since we're passing back a list...
-
             List<ScenePresence> result = new List<ScenePresence>();
-            ScenePresence[] scenePresences = GetScenePresences();
+            // Check each ScenePresence against the filter
+            ForEachScenePresence(delegate(ScenePresence presence)
+            {
+                if (filter(presence))
+                    result.Add(presence);
+            });
+            return result;
+        }
 
-            for (int i = 0; i < scenePresences.Length; i++)
+        /// <summary>
+        /// Request the ScenePresence in this region matching filter. 
+        /// Only the first match is returned. 
+        /// 
+        /// </summary>
+        /// <param name="filter"></param>
+        /// <returns></returns>
+        protected internal ScenePresence GetScenePresence(FilterAvatarList filter)
+        {
+            ScenePresence result = null;
+            // Get all of the ScenePresences
+            List<ScenePresence> presences = GetScenePresences();
+            foreach (ScenePresence presence in presences)
             {
-                ScenePresence avatar = scenePresences[i];
-                if (filter(avatar))
-                    result.Add(avatar);
+                if (filter(presence))
+                {
+                    result = presence;
+                    break;
+                }
             }
-
             return result;
         }
 
+        protected internal ScenePresence GetScenePresence(string firstName, string lastName)
+        {
+            return GetScenePresence(delegate(ScenePresence presence)
+            {
+                return(presence.Firstname == firstName && presence.Lastname == lastName);
+            });
+        }
+
         /// <summary>
         /// Request a scene presence by UUID
         /// </summary>
-        /// <param name="avatarID"></param>
+        /// <param name="agentID"></param>
         /// <returns>null if the agent was not found</returns>
         protected internal ScenePresence GetScenePresence(UUID agentID)
         {
             ScenePresence sp;
-            
-            lock (m_scenePresences)
-            {
-                m_scenePresences.TryGetValue(agentID, out sp);
-            }
-
+            TryGetAvatar(agentID, out sp);
             return sp;
         }
 
         /// <summary>
+        /// Request the ScenePresence in this region by localID.
+        /// </summary>
+        /// <param name="localID"></param>
+        /// <returns></returns>
+        protected internal ScenePresence GetScenePresence(uint localID)
+        {
+            return GetScenePresence(delegate(ScenePresence presence)
+            {
+                return (presence.LocalId == localID);
+            });
+        }
+
+        /// <summary>
         /// Get a scene object group that contains the prim with the given local id
         /// </summary>
         /// <param name="localID"></param>
@@ -910,29 +965,19 @@ namespace OpenSim.Region.Framework.Scenes
         protected internal bool TryGetAvatar(UUID avatarId, out ScenePresence avatar)
         {
             lock (m_scenePresences)
-                return m_scenePresences.TryGetValue(avatarId, out avatar);
+            {
+                m_scenePresences.TryGetValue(avatarId, out avatar);
+            }
+            return (avatar != null);
         }
 
         protected internal bool TryGetAvatarByName(string avatarName, out ScenePresence avatar)
         {
-            ScenePresence[] presences = GetScenePresences();
-
-            for (int i = 0; i < presences.Length; i++)
+            avatar = GetScenePresence(delegate(ScenePresence presence)
             {
-                ScenePresence presence = presences[i];
-
-                if (!presence.IsChildAgent)
-                {
-                    if (String.Compare(avatarName, presence.ControllingClient.Name, true) == 0)
-                    {
-                        avatar = presence;
-                        return true;
-                    }
-                }
-            }
-
-            avatar = null;
-            return false;
+                return (String.Compare(avatarName, presence.ControllingClient.Name, true) == 0);
+            });
+            return (avatar != null);
         }
 
         /// <summary>
@@ -1013,6 +1058,28 @@ namespace OpenSim.Region.Framework.Scenes
                 }
             }
         }
+
+        
+        /// <summary>
+        /// Performs action on all scene presences.
+        /// </summary>
+        /// <param name="action"></param>
+        public void ForEachScenePresence(Action<ScenePresence> action)
+        {
+            List<ScenePresence> presences = GetScenePresences();
+            try
+            {
+                foreach(ScenePresence presence in presences)
+                {
+                    action(presence);
+                }
+            }
+            catch (Exception e)
+            {
+                m_log.Info("[BUG] in " + m_parentScene.RegionInfo.RegionName + ": " + e.ToString());
+                m_log.Info("[BUG] Stack Trace: " + e.StackTrace);
+            }
+        }
         
         #endregion
 
diff --git a/OpenSim/Region/Framework/Scenes/SceneManager.cs b/OpenSim/Region/Framework/Scenes/SceneManager.cs
index 680c39a..a955532 100644
--- a/OpenSim/Region/Framework/Scenes/SceneManager.cs
+++ b/OpenSim/Region/Framework/Scenes/SceneManager.cs
@@ -414,12 +414,8 @@ namespace OpenSim.Region.Framework.Scenes
             ForEachCurrentScene(
                 delegate(Scene scene)
                 {
-                    ScenePresence[] scenePresences = scene.GetScenePresences();
-
-                    for (int i = 0; i < scenePresences.Length; i++)
+                    scene.ForEachScenePresence(delegate(ScenePresence scenePresence)
                     {
-                        ScenePresence scenePresence = scenePresences[i];
-
                         if (!scenePresence.IsChildAgent)
                         {
                             m_log.DebugFormat("Packet debug for {0} {1} set to {2}",
@@ -429,7 +425,7 @@ namespace OpenSim.Region.Framework.Scenes
 
                             scenePresence.ControllingClient.SetDebugPacketLevel(newDebug);
                         }
-                    }
+                    });
                 }
             );
         }
@@ -441,14 +437,11 @@ namespace OpenSim.Region.Framework.Scenes
             ForEachCurrentScene(
                 delegate(Scene scene)
                 {
-                    ScenePresence[] scenePresences = scene.GetScenePresences();
-
-                    for (int i = 0; i < scenePresences.Length; i++)
+                    scene.ForEachScenePresence(delegate(ScenePresence scenePresence)
                     {
-                        ScenePresence scenePresence = scenePresences[i];
                         if (!scenePresence.IsChildAgent)
                             avatars.Add(scenePresence);
-                    }
+                    });
                 }
             );
 
@@ -461,7 +454,7 @@ namespace OpenSim.Region.Framework.Scenes
 
             ForEachCurrentScene(delegate(Scene scene)
             {
-                ScenePresence[] scenePresences = scene.GetScenePresences();
+                List<ScenePresence> scenePresences = scene.GetScenePresences();
                 presences.AddRange(scenePresences);
             });
 
diff --git a/OpenSim/Region/Framework/Scenes/SceneObjectGroup.cs b/OpenSim/Region/Framework/Scenes/SceneObjectGroup.cs
index 88deedf..8aefd50 100644
--- a/OpenSim/Region/Framework/Scenes/SceneObjectGroup.cs
+++ b/OpenSim/Region/Framework/Scenes/SceneObjectGroup.cs
@@ -1268,22 +1268,20 @@ namespace OpenSim.Region.Framework.Scenes
                 foreach (SceneObjectPart part in m_parts.Values)
                 {
 //                    part.Inventory.RemoveScriptInstances();
-
-                    ScenePresence[] avatars = Scene.GetScenePresences();
-                    for (int i = 0; i < avatars.Length; i++)
+                    Scene.ForEachScenePresence(delegate(ScenePresence avatar)
                     {
-                        if (avatars[i].ParentID == LocalId)
+                        if (avatar.ParentID == LocalId)
                         {
-                            avatars[i].StandUp();
+                            avatar.StandUp();
                         }
 
                         if (!silent)
                         {
                             part.UpdateFlag = 0;
                             if (part == m_rootPart)
-                                avatars[i].ControllingClient.SendKillObject(m_regionHandle, part.LocalId);
+                                avatar.ControllingClient.SendKillObject(m_regionHandle, part.LocalId);
                         }
-                    }
+                    });
                 }
             }
         }
diff --git a/OpenSim/Region/Framework/Scenes/SceneObjectPart.cs b/OpenSim/Region/Framework/Scenes/SceneObjectPart.cs
index a2b98b9..0e21487 100644
--- a/OpenSim/Region/Framework/Scenes/SceneObjectPart.cs
+++ b/OpenSim/Region/Framework/Scenes/SceneObjectPart.cs
@@ -1197,15 +1197,14 @@ namespace OpenSim.Region.Framework.Scenes
 
         private void SendObjectPropertiesToClient(UUID AgentID)
         {
-            ScenePresence[] avatars = m_parentGroup.Scene.GetScenePresences();
-            for (int i = 0; i < avatars.Length; i++)
+            m_parentGroup.Scene.ForEachScenePresence(delegate(ScenePresence avatar)
             {
                 // Ugly reference :(
-                if (avatars[i].UUID == AgentID)
+                if (avatar.UUID == AgentID)
                 {
-                    m_parentGroup.GetProperties(avatars[i].ControllingClient);
+                    m_parentGroup.GetProperties(avatar.ControllingClient);
                 }
-            }
+            });
         }
 
         // TODO: unused:
@@ -1260,11 +1259,10 @@ namespace OpenSim.Region.Framework.Scenes
         /// </summary>
         public void AddFullUpdateToAllAvatars()
         {
-            ScenePresence[] avatars = m_parentGroup.Scene.GetScenePresences();
-            for (int i = 0; i < avatars.Length; i++)
+            m_parentGroup.Scene.ForEachScenePresence(delegate(ScenePresence avatar)
             {
-                avatars[i].SceneViewer.QueuePartForUpdate(this);
-            }
+                avatar.SceneViewer.QueuePartForUpdate(this);
+            });
         }
 
         public void AddFullUpdateToAvatar(ScenePresence presence)
@@ -1285,11 +1283,10 @@ namespace OpenSim.Region.Framework.Scenes
         /// Terse updates
         public void AddTerseUpdateToAllAvatars()
         {
-            ScenePresence[] avatars = m_parentGroup.Scene.GetScenePresences();
-            for (int i = 0; i < avatars.Length; i++)
+            m_parentGroup.Scene.ForEachScenePresence(delegate(ScenePresence avatar)
             {
-                avatars[i].SceneViewer.QueuePartForUpdate(this);
-            }
+                avatar.SceneViewer.QueuePartForUpdate(this);
+            });
         }
 
         public void AddTerseUpdateToAvatar(ScenePresence presence)
@@ -2121,17 +2118,13 @@ namespace OpenSim.Region.Framework.Scenes
                         }
                         else
                         {
-                            ScenePresence[] avlist = m_parentGroup.Scene.GetScenePresences();
-
-                            for (int i = 0; i < avlist.Length; i++)
+                            m_parentGroup.Scene.ForEachScenePresence(delegate(ScenePresence av)
                             {
-                                ScenePresence av = avlist[i];
-
                                 if (av.LocalId == localId)
                                 {
                                     if (m_parentGroup.RootPart.CollisionFilter.ContainsValue(av.UUID.ToString()) || m_parentGroup.RootPart.CollisionFilter.ContainsValue(av.Name))
                                     {
-                                        bool found = m_parentGroup.RootPart.CollisionFilter.TryGetValue(1,out data);
+                                        bool found = m_parentGroup.RootPart.CollisionFilter.TryGetValue(1, out data);
                                         //If it is 1, it is to accept ONLY collisions from this avatar
                                         if (found)
                                         {
@@ -2153,7 +2146,7 @@ namespace OpenSim.Region.Framework.Scenes
                                     }
                                     else
                                     {
-                                        bool found = m_parentGroup.RootPart.CollisionFilter.TryGetValue(1,out data);
+                                        bool found = m_parentGroup.RootPart.CollisionFilter.TryGetValue(1, out data);
                                         //If it is 1, it is to accept ONLY collisions from this avatar, so this other avatar will not work
                                         if (!found)
                                         {
@@ -2171,7 +2164,7 @@ namespace OpenSim.Region.Framework.Scenes
                                     }
 
                                 }
-                            }
+                            });
                         }
                     }
                     if (colliding.Count > 0)
@@ -2257,17 +2250,13 @@ namespace OpenSim.Region.Framework.Scenes
                         }
                         else
                         {
-                            ScenePresence[] avlist = m_parentGroup.Scene.GetScenePresences();
-
-                            for (int i = 0; i < avlist.Length; i++)
+                            m_parentGroup.Scene.ForEachScenePresence(delegate(ScenePresence av)
                             {
-                                ScenePresence av = avlist[i];
-
                                 if (av.LocalId == localId)
                                 {
                                     if (m_parentGroup.RootPart.CollisionFilter.ContainsValue(av.UUID.ToString()) || m_parentGroup.RootPart.CollisionFilter.ContainsValue(av.Name))
                                     {
-                                        bool found = m_parentGroup.RootPart.CollisionFilter.TryGetValue(1,out data);
+                                        bool found = m_parentGroup.RootPart.CollisionFilter.TryGetValue(1, out data);
                                         //If it is 1, it is to accept ONLY collisions from this avatar
                                         if (found)
                                         {
@@ -2289,7 +2278,7 @@ namespace OpenSim.Region.Framework.Scenes
                                     }
                                     else
                                     {
-                                        bool found = m_parentGroup.RootPart.CollisionFilter.TryGetValue(1,out data);
+                                        bool found = m_parentGroup.RootPart.CollisionFilter.TryGetValue(1, out data);
                                         //If it is 1, it is to accept ONLY collisions from this avatar, so this other avatar will not work
                                         if (!found)
                                         {
@@ -2307,7 +2296,7 @@ namespace OpenSim.Region.Framework.Scenes
                                     }
 
                                 }
-                            }
+                            });
                         }
                     }
                     if (colliding.Count > 0)
@@ -2388,17 +2377,13 @@ namespace OpenSim.Region.Framework.Scenes
                         }
                         else
                         {
-                            ScenePresence[] avlist = m_parentGroup.Scene.GetScenePresences();
-
-                            for (int i = 0; i < avlist.Length; i++)
+                            m_parentGroup.Scene.ForEachScenePresence(delegate(ScenePresence av)
                             {
-                                ScenePresence av = avlist[i];
-
                                 if (av.LocalId == localId)
                                 {
                                     if (m_parentGroup.RootPart.CollisionFilter.ContainsValue(av.UUID.ToString()) || m_parentGroup.RootPart.CollisionFilter.ContainsValue(av.Name))
                                     {
-                                        bool found = m_parentGroup.RootPart.CollisionFilter.TryGetValue(1,out data);
+                                        bool found = m_parentGroup.RootPart.CollisionFilter.TryGetValue(1, out data);
                                         //If it is 1, it is to accept ONLY collisions from this avatar
                                         if (found)
                                         {
@@ -2420,7 +2405,7 @@ namespace OpenSim.Region.Framework.Scenes
                                     }
                                     else
                                     {
-                                        bool found = m_parentGroup.RootPart.CollisionFilter.TryGetValue(1,out data);
+                                        bool found = m_parentGroup.RootPart.CollisionFilter.TryGetValue(1, out data);
                                         //If it is 1, it is to accept ONLY collisions from this avatar, so this other avatar will not work
                                         if (!found)
                                         {
@@ -2438,7 +2423,7 @@ namespace OpenSim.Region.Framework.Scenes
                                     }
 
                                 }
-                            }
+                            });
                         }
                     }
                     
@@ -2877,11 +2862,10 @@ namespace OpenSim.Region.Framework.Scenes
         /// </summary>
         public void SendFullUpdateToAllClients()
         {
-            ScenePresence[] avatars = m_parentGroup.Scene.GetScenePresences();
-            for (int i = 0; i < avatars.Length; i++)
+            m_parentGroup.Scene.ForEachScenePresence(delegate(ScenePresence avatar)
             {
-                SendFullUpdate(avatars[i].ControllingClient, avatars[i].GenerateClientFlags(UUID));
-            }
+                SendFullUpdate(avatar.ControllingClient, avatar.GenerateClientFlags(UUID));
+            });
         }
 
         /// <summary>
@@ -2890,13 +2874,12 @@ namespace OpenSim.Region.Framework.Scenes
         /// <param name="agentID"></param>
         public void SendFullUpdateToAllClientsExcept(UUID agentID)
         {
-            ScenePresence[] avatars = m_parentGroup.Scene.GetScenePresences();
-            for (int i = 0; i < avatars.Length; i++)
+            m_parentGroup.Scene.ForEachScenePresence(delegate(ScenePresence avatar)
             {
                 // Ugly reference :(
-                if (avatars[i].UUID != agentID)
-                    SendFullUpdate(avatars[i].ControllingClient, avatars[i].GenerateClientFlags(UUID));
-            }
+                if (avatar.UUID != agentID)
+                    SendFullUpdate(avatar.ControllingClient, avatar.GenerateClientFlags(UUID));
+            });
         }
 
         /// <summary>
@@ -3096,11 +3079,10 @@ namespace OpenSim.Region.Framework.Scenes
         /// </summary>
         public void SendTerseUpdateToAllClients()
         {
-            ScenePresence[] avatars = m_parentGroup.Scene.GetScenePresences();
-            for (int i = 0; i < avatars.Length; i++)
+            m_parentGroup.Scene.ForEachScenePresence(delegate(ScenePresence avatar)
             {
-                SendTerseUpdateToClient(avatars[i].ControllingClient);
-            }
+                SendTerseUpdateToClient(avatar.ControllingClient);
+            });
         }
 
         public void SetAttachmentPoint(uint AttachmentPoint)
diff --git a/OpenSim/Region/Framework/Scenes/ScenePresence.cs b/OpenSim/Region/Framework/Scenes/ScenePresence.cs
index 6f16ff3..766f6d3 100644
--- a/OpenSim/Region/Framework/Scenes/ScenePresence.cs
+++ b/OpenSim/Region/Framework/Scenes/ScenePresence.cs
@@ -912,14 +912,11 @@ namespace OpenSim.Region.Framework.Scenes
 
             m_isChildAgent = false;
 
-            ScenePresence[] animAgents = m_scene.GetScenePresences();
-            for (int i = 0; i < animAgents.Length; i++)
+            m_scene.ForEachScenePresence(delegate(ScenePresence presence)
             {
-                ScenePresence presence = animAgents[i];
-
                 if (presence != this)
                     presence.Animator.SendAnimPackToClient(ControllingClient);
-            }
+            });
 
             m_scene.EventManager.TriggerOnMakeRootAgent(this);
         }
@@ -2469,13 +2466,10 @@ namespace OpenSim.Region.Framework.Scenes
         public void SendInitialFullUpdateToAllClients()
         {
             m_perfMonMS = Util.EnvironmentTickCount();
-
-            ScenePresence[] avatars = m_scene.GetScenePresences();
-
-            for (int i = 0; i < avatars.Length; i++)
+            int avUpdates = 0;
+            m_scene.ForEachScenePresence(delegate(ScenePresence avatar)
             {
-                ScenePresence avatar = avatars[i];
-
+                ++avUpdates;
                 // only send if this is the root (children are only "listening posts" in a foreign region)
                 if (!IsChildAgent)
                 {
@@ -2491,9 +2485,9 @@ namespace OpenSim.Region.Framework.Scenes
                         avatar.Animator.SendAnimPackToClient(ControllingClient);
                     }
                 }
-            }
+            });
 
-            m_scene.StatsReporter.AddAgentUpdates(avatars.Length);
+            m_scene.StatsReporter.AddAgentUpdates(avUpdates);
             m_scene.StatsReporter.AddAgentTime(Util.EnvironmentTickCountSubtract(m_perfMonMS));
 
             //Animator.SendAnimPack();
diff --git a/OpenSim/Region/UserStatistics/ActiveConnectionsAJAX.cs b/OpenSim/Region/UserStatistics/ActiveConnectionsAJAX.cs
index 704b74f..a567413 100644
--- a/OpenSim/Region/UserStatistics/ActiveConnectionsAJAX.cs
+++ b/OpenSim/Region/UserStatistics/ActiveConnectionsAJAX.cs
@@ -68,7 +68,7 @@ namespace OpenSim.Region.UserStatistics
             HTMLUtil.OL_O(ref output, "");
             foreach (Scene scene in all_scenes)
             {
-                ScenePresence[] avatarInScene = scene.GetScenePresences();
+                List<ScenePresence> avatarInScene = scene.GetScenePresences();
 
                 HTMLUtil.LI_O(ref output, String.Empty);
                 output.Append(scene.RegionInfo.RegionName);