Rewrote parts of the code that were double-locking different objects. This is about half of the code base reviewed.

OpenSim/Framework/Communications/Cache/UserProfileCacheService.cs

@@ -128,16 +128,12 @@ namespace OpenSim.Framework.Communications.Cache
         /// <returns>null if no user details are found</returns>
         public CachedUserInfo GetUserDetails(string fname, string lname)
         {
+            CachedUserInfo userInfo;
             lock (m_userProfilesByName)
             {    
-                CachedUserInfo userInfo;
-                
                 if (m_userProfilesByName.TryGetValue(string.Format(NAME_FORMAT, fname, lname), out userInfo))
-                {
                     return userInfo;
             }
-                else
-                {
             UserProfileData userProfile = m_commsManager.UserService.GetUserProfile(fname, lname);
         
             if (userProfile != null)
@@ -145,8 +141,6 @@ namespace OpenSim.Framework.Communications.Cache
             else
                 return null;
         }
-            }
-        }
         
         /// <summary>
         /// Get details of the given user.
@@ -160,21 +154,15 @@ namespace OpenSim.Framework.Communications.Cache
                 return null;
 
             lock (m_userProfilesById)
-            {
                 if (m_userProfilesById.ContainsKey(userID))
-                {
                     return m_userProfilesById[userID];
-                }
+
-                else
-                {
             UserProfileData userProfile = m_commsManager.UserService.GetUserProfile(userID);
             if (userProfile != null)
                 return AddToCaches(userProfile);
             else
                 return null;
         }
-            }
-        }
         
         /// <summary>
         /// Update an existing profile
@@ -211,14 +199,10 @@ namespace OpenSim.Framework.Communications.Cache
             CachedUserInfo createdUserInfo = new CachedUserInfo(m_InventoryService, userProfile);
             
             lock (m_userProfilesById)
-            {
                 m_userProfilesById[createdUserInfo.UserProfile.ID] = createdUserInfo;
 
             lock (m_userProfilesByName)
-                {
                 m_userProfilesByName[createdUserInfo.UserProfile.Name] = createdUserInfo;
-                }
-            }
             
             return createdUserInfo;
         }
@@ -230,18 +214,22 @@ namespace OpenSim.Framework.Communications.Cache
         /// <returns>true if there was a profile to remove, false otherwise</returns>
         protected bool RemoveFromCaches(UUID userId)
         {
+            CachedUserInfo userInfo = null;
             lock (m_userProfilesById)
             {
                 if (m_userProfilesById.ContainsKey(userId))
                 {
-                    CachedUserInfo userInfo = m_userProfilesById[userId];
+                    userInfo = m_userProfilesById[userId];
                     m_userProfilesById.Remove(userId);
-                    
+                }
-                    lock (m_userProfilesByName)
-                    {
-                        m_userProfilesByName.Remove(userInfo.UserProfile.Name);
             }
 
+            if (userInfo != null)
+                lock (m_userProfilesByName)
+                {
+                    if (m_userProfilesByName.ContainsKey(userInfo.UserProfile.Name))
+                    {
+                        m_userProfilesByName.Remove(userInfo.UserProfile.Name);
                         return true;
                     }
                 }

OpenSim/Region/ClientStack/LindenUDP/LLClientView.cs

@@ -3122,6 +3122,7 @@ namespace OpenSim.Region.ClientStack.LindenUDP
                 objectData.TextureAnim = textureanim;
             }
 
+            bool doUpdate = false;
             lock (m_primFullUpdates)
             {
                 if (m_primFullUpdates.Count == 0)
@@ -3130,8 +3131,10 @@ namespace OpenSim.Region.ClientStack.LindenUDP
                 m_primFullUpdates.Add(objectData);
 
                 if (m_primFullUpdates.Count >= m_primFullUpdatesPerPacket)
-                    ProcessPrimFullUpdates(this, null);
+                    doUpdate = true;
             }
+            if (doUpdate)
+                ProcessPrimFullUpdates(this, null);
         }
 
         void HandleQueueEmpty(ThrottleOutPacketType queue)
@@ -3152,13 +3155,16 @@ namespace OpenSim.Region.ClientStack.LindenUDP
 
         void ProcessPrimFullUpdates(object sender, ElapsedEventArgs e)
         {
+            bool stopTimer = false;
             lock (m_primFullUpdates)
             {
                 if (m_primFullUpdates.Count == 0 && m_primFullUpdateTimer.Enabled)
+                    stopTimer = true;
+            }
+            if (stopTimer)
             {
                 lock (m_primFullUpdateTimer)
                     m_primFullUpdateTimer.Stop();
-
                 return;
             }
 
@@ -3181,6 +3187,8 @@ namespace OpenSim.Region.ClientStack.LindenUDP
             byte[] zerobuffer = new byte[1024];
             byte[] blockbuffer = new byte[1024];
 
+            lock (m_primFullUpdates)
+            {
                 for (count = 0 ; count < max ; count++)
                 {
                     int length = 0;
@@ -3204,10 +3212,13 @@ namespace OpenSim.Region.ClientStack.LindenUDP
                 OutPacket(outPacket, ThrottleOutPacketType.Task | ThrottleOutPacketType.LowPriority);
 
                 if (m_primFullUpdates.Count == 0 && m_primFullUpdateTimer.Enabled)
+                    stopTimer = true;
+            }
+
+            if (stopTimer)
                 lock (m_primFullUpdateTimer)
                     m_primFullUpdateTimer.Stop();
         }
-        }
 
         /// <summary>
         ///
@@ -3225,6 +3236,7 @@ namespace OpenSim.Region.ClientStack.LindenUDP
                     CreatePrimImprovedBlock(localID, position, rotation,
                     velocity, rotationalvelocity, state);
 
+            bool doUpdate = false;
             lock (m_primTerseUpdates)
             {
                 if (m_primTerseUpdates.Count == 0)
@@ -3233,15 +3245,21 @@ namespace OpenSim.Region.ClientStack.LindenUDP
                 m_primTerseUpdates.Add(objectData);
 
                 if (m_primTerseUpdates.Count >= m_primTerseUpdatesPerPacket)
-                    ProcessPrimTerseUpdates(this, null);
+                    doUpdate = true;
             }
+            if (doUpdate)
+                ProcessPrimTerseUpdates(this, null);
         }
 
         void ProcessPrimTerseUpdates(object sender, ElapsedEventArgs e)
         {
+            bool stopTimer = false;
             lock (m_primTerseUpdates)
             {
                 if (m_primTerseUpdates.Count == 0)
+                    stopTimer = true;
+            }
+            if (stopTimer)
             {
                 lock (m_primTerseUpdateTimer)
                     m_primTerseUpdateTimer.Stop();
@@ -3269,7 +3287,9 @@ namespace OpenSim.Region.ClientStack.LindenUDP
             byte[] zerobuffer = new byte[1024];
             byte[] blockbuffer = new byte[1024];
 
-                for (count = 0 ; count < max ; count++)
+            lock (m_primTerseUpdates)
+            {
+                for (count = 0; count < max; count++)
                 {
                     int length = 0;
                     m_primTerseUpdates[count].ToBytes(blockbuffer, ref length);
@@ -3294,10 +3314,12 @@ namespace OpenSim.Region.ClientStack.LindenUDP
                 OutPacket(outPacket, ThrottleOutPacketType.Task | ThrottleOutPacketType.LowPriority);
 
                 if (m_primTerseUpdates.Count == 0)
+                    stopTimer = true;
+            }
+            if (stopTimer)
                 lock (m_primTerseUpdateTimer)
                     m_primTerseUpdateTimer.Stop();
         }
-        }
 
         public void FlushPrimUpdates()
         {

OpenSim/Region/CoreModules/Avatar/Friends/FriendsModule.cs

@@ -442,11 +442,13 @@ namespace OpenSim.Region.CoreModules.Avatar.Friends
 
         private ScenePresence GetRootPresenceFromAgentID(UUID AgentID)
         {
-            ScenePresence returnAgent = null;
+            List<Scene> scenes = null;
             lock (m_scenes)
-            {
+                scenes = new List<Scene>(m_scenes.Values);
+
+            ScenePresence returnAgent = null;
             ScenePresence queryagent = null;
-                foreach (Scene scene in m_scenes.Values)
+            foreach (Scene scene in scenes)
             {
                 queryagent = scene.GetScenePresence(AgentID);
                 if (queryagent != null)
@@ -458,15 +460,17 @@ namespace OpenSim.Region.CoreModules.Avatar.Friends
                     }
                 }
             }
-            }
+
             return returnAgent;
         }
 
         private ScenePresence GetAnyPresenceFromAgentID(UUID AgentID)
         {
-            ScenePresence returnAgent = null;
+            List<Scene> scenes = null;
             lock (m_scenes)
-            {
+                scenes = new List<Scene>(m_scenes.Values);
+
+            ScenePresence returnAgent = null;
             ScenePresence queryagent = null;
             foreach (Scene scene in m_scenes.Values)
             {
@@ -477,7 +481,7 @@ namespace OpenSim.Region.CoreModules.Avatar.Friends
                     break;
                 }
             }
-            }
+ 
             return returnAgent;
         }
         

OpenSim/Region/CoreModules/Avatar/InstantMessage/PresenceModule.cs

@@ -290,14 +290,15 @@ namespace OpenSim.Region.CoreModules.Avatar.InstantMessage
 
             // get the agent. This should work every time, as we just got a packet from it
             ScenePresence agent = null;
+            List<Scene> scenes = null;
             lock (m_Scenes)
-            {
+                scenes = new List<Scene>(m_Scenes);
-                foreach (Scene scene in m_Scenes)
+
+            foreach (Scene scene in scenes)
             {
                 agent = scene.GetScenePresence(agentID);
                 if (agent != null) break;
             }
-            }
 
             // just to be paranoid...
             if (agent == null)

OpenSim/Region/CoreModules/Avatar/Inventory/Transfer/InventoryTransferModule.cs

@@ -111,9 +111,11 @@ namespace OpenSim.Region.CoreModules.Avatar.Inventory.Transfer
 
         private Scene FindClientScene(UUID agentId)
         {
+            List<Scene> scenes = null;
             lock (m_Scenelist)
-            {
+                scenes = new List<Scene>(m_Scenelist);
-                foreach (Scene scene in m_Scenelist)
+
+            foreach (Scene scene in scenes)
             {
                 ScenePresence presence = scene.GetScenePresence(agentId);
                 if (presence != null)
@@ -122,7 +124,6 @@ namespace OpenSim.Region.CoreModules.Avatar.Inventory.Transfer
                         return scene;
                 }
             }
-            }
             return null;
         }
 

OpenSim/Region/CoreModules/Scripting/EMailModules/EmailModule.cs

@@ -198,9 +198,11 @@ namespace OpenSim.Region.CoreModules.Scripting.EmailModules
 
         private SceneObjectPart findPrim(UUID objectID, out string ObjectRegionName)
         {
+            List<Scene> scenes = null;
             lock (m_Scenes)
-            {
+                scenes = new List<Scene>(m_Scenes.Values);
-                foreach (Scene s in m_Scenes.Values)
+
+            foreach (Scene s in scenes)
             {
                 SceneObjectPart part = s.GetSceneObjectPart(objectID);
                 if (part != null)
@@ -212,7 +214,6 @@ namespace OpenSim.Region.CoreModules.Scripting.EmailModules
                     return part;
                 }
             }
-            }
             ObjectRegionName = string.Empty;
             return null;
         }
@@ -363,6 +364,7 @@ namespace OpenSim.Region.CoreModules.Scripting.EmailModules
         public Email GetNextEmail(UUID objectID, string sender, string subject)
         {
             List<Email> queue = null;
+            List<UUID> removal = new List<UUID>();
 
             lock (m_LastGetEmailCall)
             {
@@ -375,7 +377,6 @@ namespace OpenSim.Region.CoreModules.Scripting.EmailModules
 
                 // Hopefully this isn't too time consuming.  If it is, we can always push it into a worker thread.
                 DateTime now = DateTime.Now;
-                List<UUID> removal = new List<UUID>();
                 foreach (UUID uuid in m_LastGetEmailCall.Keys)
                 {
                     if ((now - m_LastGetEmailCall[uuid]) > m_QueueTimeout)
@@ -383,16 +384,16 @@ namespace OpenSim.Region.CoreModules.Scripting.EmailModules
                         removal.Add(uuid);
                     }
                 }
+            }
 
             foreach (UUID remove in removal)
             {
+                lock (m_LastGetEmailCall)
                     m_LastGetEmailCall.Remove(remove);
+    
                 lock (m_MailQueues)
-                    {
                     m_MailQueues.Remove(remove);
             }
-                }
-            }
 
             lock (m_MailQueues)
             {

OpenSim/Region/CoreModules/World/Land/LandManagementModule.cs

@@ -187,14 +187,16 @@ namespace OpenSim.Region.CoreModules.World.Land
             LandData newData = data.Copy();
             newData.LocalID = local_id;
 
+            ILandObject land = null;
             lock (m_landList)
             {
                 if (m_landList.ContainsKey(local_id))
                 {
                     m_landList[local_id].LandData = newData;
-                    m_scene.EventManager.TriggerLandObjectUpdated((uint)local_id, m_landList[local_id]);
+                    land = m_landList[local_id];
                 }
             }
+            m_scene.EventManager.TriggerLandObjectUpdated((uint)local_id, land);
         }
 
         public bool AllowedForcefulBans
@@ -504,6 +506,7 @@ namespace OpenSim.Region.CoreModules.World.Land
         /// <param name="local_id">Land.localID of the peice of land to remove.</param>
         public void removeLandObject(int local_id)
         {
+            UUID id = UUID.Zero;
             lock (m_landList)
             {
                 for (int x = 0; x < 64; x++)
@@ -520,9 +523,10 @@ namespace OpenSim.Region.CoreModules.World.Land
                     }
                 }
 
-                m_scene.EventManager.TriggerLandObjectRemoved(m_landList[local_id].LandData.GlobalID);
+                id = m_landList[local_id].LandData.GlobalID;
                 m_landList.Remove(local_id);
             }
+            m_scene.EventManager.TriggerLandObjectRemoved(id);
         }
 
         private void performFinalLandJoin(ILandObject master, ILandObject slave)

OpenSim/Region/Framework/Scenes/AsyncSceneObjectGroupDeleter.cs

@@ -122,12 +122,13 @@ namespace OpenSim.Region.Framework.Scenes
         public bool InventoryDeQueueAndDelete()
         {
             DeleteToInventoryHolder x = null;
+            int left = 0;
  
             try
             {
                 lock (m_inventoryDeletes)
                 {
-                    int left = m_inventoryDeletes.Count;
+                    left = m_inventoryDeletes.Count;
                     if (left > 0)
                     {
                         x = m_inventoryDeletes.Dequeue();
@@ -136,7 +137,11 @@ namespace OpenSim.Region.Framework.Scenes
                             m_inventoryDeletes.Enqueue(x);
                             return true;
                         }
+                    }
+                }
 
+                if (left > 0)
+                {
                     m_log.DebugFormat(
                         "[SCENE]: Sending object to user's inventory, {0} item(s) remaining.", left);
                     
@@ -154,7 +159,6 @@ namespace OpenSim.Region.Framework.Scenes
                     return true;
                 }
             }
-            }
             catch (Exception e)
             {
                 // We can't put the object group details in here since the root part may have disappeared (which is where these sit).

OpenSim/Region/Framework/Scenes/SceneGraph.cs

@@ -297,33 +297,43 @@ namespace OpenSim.Region.Framework.Scenes
 
             sceneObject.AttachToScene(m_parentScene);
 
+            List<SceneObjectPart> parts = null;
+            bool found = false;
             lock (sceneObject)
             {
                 if (!Entities.ContainsKey(sceneObject.UUID))
                 {
+                    found = true;
                     Entities.Add(sceneObject);
                     m_numPrim += sceneObject.Children.Count;
 
                     if (attachToBackup)
                         sceneObject.AttachToBackup();
 
-                    if (OnObjectCreate != null)
+                    parts = new List<SceneObjectPart>(sceneObject.Children.Values);
-                        OnObjectCreate(sceneObject);
 
+                }
+            }
+
+            if (found)
+            {
                 lock (m_dictionary_lock)
                 {
                     SceneObjectGroupsByFullID[sceneObject.UUID] = sceneObject;
                     SceneObjectGroupsByLocalID[sceneObject.LocalId] = sceneObject;
-                        foreach (SceneObjectPart part in sceneObject.Children.Values)
+                    foreach (SceneObjectPart part in parts)
                     {
                         SceneObjectGroupsByFullID[part.UUID] = sceneObject;
                         SceneObjectGroupsByLocalID[part.LocalId] = sceneObject;
                     }
                 }
 
+                if (OnObjectCreate != null)
+                    OnObjectCreate(sceneObject);
+
                 return true;
             }
-            }
+
 
             return false;
         }