Improve consistency of locking for SOG.m_parts in order to avoid race conditions in linking and unlinking

OpenSim/Data/MSSQL/MSSQLLegacyRegionData.cs

@@ -232,7 +232,9 @@ namespace OpenSim.Data.MSSQL
         /// <param name="regionUUID"></param>
         public void StoreObject(SceneObjectGroup obj, UUID regionUUID)
         {
-            _Log.InfoFormat("[MSSQL]: Adding/Changing SceneObjectGroup: {0} to region: {1}, object has {2} prims.", obj.UUID, regionUUID, obj.Children.Count);
+            lock (obj.Children)
+            {
+                _Log.DebugFormat("[MSSQL]: Adding/Changing SceneObjectGroup: {0} to region: {1}, object has {2} prims.", obj.UUID, regionUUID, obj.Children.Count);
     
                 using (SqlConnection conn = new SqlConnection(m_connectionString))
                 {
@@ -291,7 +293,7 @@ namespace OpenSim.Data.MSSQL
                         }
                     }
                 }
-
+            }
         }
 
         /// <summary>

OpenSim/Data/MySQL/MySQLLegacyRegionData.cs

@@ -135,6 +135,8 @@ namespace OpenSim.Data.MySQL
                     dbcon.Open();
                     MySqlCommand cmd = dbcon.CreateCommand();
 
+                    lock (obj.Children)
+                    {
                         foreach (SceneObjectPart prim in obj.Children.Values)
                         {
                             cmd.Parameters.Clear();
@@ -239,10 +241,12 @@ namespace OpenSim.Data.MySQL
     
                             ExecuteNonQuery(cmd);
                         }
+                        
                         cmd.Dispose();
                     }
                 }
             }
+        }
 
         public void RemoveObject(UUID obj, UUID regionUUID)
         {

OpenSim/Data/SQLite/SQLiteRegionData.cs

@@ -359,6 +359,8 @@ namespace OpenSim.Data.SQLite
                 return;
 
             lock (ds)
+            {
+                lock (obj.Children)
                 {
                     foreach (SceneObjectPart prim in obj.Children.Values)
                     {
@@ -366,6 +368,7 @@ namespace OpenSim.Data.SQLite
                         addPrim(prim, obj.UUID, regionUUID);
                     }
                 }
+            }
 
             Commit();
             // m_log.Info("[Dump of prims]: " + ds.GetXml());

OpenSim/Data/SQLiteLegacy/SQLiteRegionData.cs

@@ -326,6 +326,8 @@ namespace OpenSim.Data.SQLiteLegacy
                 return;
 
             lock (ds)
+            {
+                lock (obj.Children)
                 {
                     foreach (SceneObjectPart prim in obj.Children.Values)
                     {
@@ -333,6 +335,7 @@ namespace OpenSim.Data.SQLiteLegacy
                         addPrim(prim, obj.UUID, regionUUID);
                     }
                 }
+            }
 
             Commit();
             // m_log.Info("[Dump of prims]: " + ds.GetXml());

OpenSim/Region/CoreModules/Avatar/Attachments/AttachmentsModule.cs

@@ -406,7 +406,7 @@ namespace OpenSim.Region.CoreModules.Avatar.Attachments
             if (m_scene.TryGetScenePresence(remoteClient.AgentId, out presence))
             {
                 if (!m_scene.Permissions.CanRezObject(
-                        part.ParentGroup.Children.Count, remoteClient.AgentId, presence.AbsolutePosition))
+                    part.ParentGroup.PrimCount, remoteClient.AgentId, presence.AbsolutePosition))
                     return;
 
                 presence.Appearance.DetachAttachment(itemID);

OpenSim/Region/CoreModules/Framework/InventoryAccess/InventoryAccessModule.cs

@@ -526,7 +526,7 @@ namespace OpenSim.Region.CoreModules.Framework.InventoryAccess
                         group.RootPart.CreateSelected = true;
 
                     if (!m_Scene.Permissions.CanRezObject(
-                        group.Children.Count, remoteClient.AgentId, pos)
+                        group.PrimCount, remoteClient.AgentId, pos)
                         && !attachment)
                     {
                         // The client operates in no fail mode. It will
@@ -594,7 +594,9 @@ namespace OpenSim.Region.CoreModules.Framework.InventoryAccess
                     rootPart.Name = item.Name;
                     rootPart.Description = item.Description;
 
-                    List<SceneObjectPart> partList = new List<SceneObjectPart>(group.Children.Values);
+                    List<SceneObjectPart> partList = null;                    
+                    lock (group.Children)
+                        partList = new List<SceneObjectPart>(group.Children.Values);
 
                     group.SetGroup(remoteClient.ActiveGroupId, remoteClient);
                     if ((rootPart.OwnerID != item.Owner) || (item.CurrentPermissions & 16) != 0)

OpenSim/Region/CoreModules/World/Archiver/ArchiveReadRequest.cs

@@ -243,6 +243,8 @@ namespace OpenSim.Region.CoreModules.World.Archiver
                 // to the same scene (when this is possible).
                 sceneObject.ResetIDs();
 
+                lock (sceneObject.Children)
+                {
                     foreach (SceneObjectPart part in sceneObject.Children.Values)
                     {
                         if (!ResolveUserUuid(part.CreatorID))
@@ -277,6 +279,7 @@ namespace OpenSim.Region.CoreModules.World.Archiver
                             }
                         }
                     }
+                }
 
                 if (m_scene.AddRestoredSceneObject(sceneObject, true, false))
                 {

OpenSim/Region/CoreModules/World/Objects/BuySell/BuySellModule.cs

@@ -128,7 +128,10 @@ namespace OpenSim.Region.CoreModules.World.Objects.BuySell
                 group.SetOwnerId(remoteClient.AgentId);
                 group.SetRootPartOwner(part, remoteClient.AgentId, remoteClient.ActiveGroupId);
 
-                List<SceneObjectPart> partList = new List<SceneObjectPart>(group.Children.Values);
+                List<SceneObjectPart> partList = null;
+                
+                lock (group.Children)
+                    partList = new List<SceneObjectPart>(group.Children.Values);
 
                 if (m_scene.Permissions.PropagatePermissions())
                 {

OpenSim/Region/CoreModules/World/WorldMap/MapImageModule.cs

@@ -227,7 +227,10 @@ namespace OpenSim.Region.CoreModules.World.WorldMap
                     {
                         SceneObjectGroup mapdot = (SceneObjectGroup)obj;
                         Color mapdotspot = Color.Gray; // Default color when prim color is white
+                        
                         // Loop over prim in group
+                        lock (mapdot.Children)
+                        {
                             foreach (SceneObjectPart part in mapdot.Children.Values)
                             {
                                 if (part == null)
@@ -498,6 +501,7 @@ namespace OpenSim.Region.CoreModules.World.WorldMap
                                         //}
                                     } // Object is within 256m Z of terrain
                                 } // object is at least a meter wide
+                            } // mapdot.Children lock
                         } // loop over group children
                     } // entitybase is sceneobject group
                 } // foreach loop over entities

OpenSim/Region/Framework/Scenes/Scene.Inventory.cs

@@ -1974,7 +1974,7 @@ namespace OpenSim.Region.Framework.Scenes
             if (null == group)
                 return null;
             
-            if (!Permissions.CanRezObject(group.Children.Count, item.OwnerID, pos))
+            if (!Permissions.CanRezObject(group.PrimCount, item.OwnerID, pos))
                 return null;            
 
             if (!Permissions.BypassPermissions())
@@ -2051,9 +2051,12 @@ namespace OpenSim.Region.Framework.Scenes
                     sog.SetGroup(groupID, remoteClient);
                     sog.ScheduleGroupForFullUpdate();
 
+                    lock (sog.Children)
+                    {
                         foreach (SceneObjectPart child in sog.Children.Values)
                             child.Inventory.ChangeInventoryOwner(ownerID);
                     }
+                }
                 else
                 {
                     if (!Permissions.CanEditObject(sog.UUID, remoteClient.AgentId))
@@ -2062,16 +2065,18 @@ namespace OpenSim.Region.Framework.Scenes
                     if (sog.GroupID != groupID)
                         continue;
 
+                    lock (sog.Children)
+                    {
                         foreach (SceneObjectPart child in sog.Children.Values)
                         {
                             child.LastOwnerID = child.OwnerID;
                             child.Inventory.ChangeInventoryOwner(groupID);
                         }
+                    }
 
                     sog.SetOwnerId(groupID);
                     sog.ApplyNextOwnerPermissions();
                 }                
-                
             }
 
             foreach (uint localID in localIDs)

OpenSim/Region/Framework/Scenes/Scene.PacketHandlers.cs

@@ -161,7 +161,12 @@ namespace OpenSim.Region.Framework.Scenes
                         // We also need to check the children of this prim as they
                         // can be selected as well and send property information
                         bool foundPrim = false;
-                       foreach (KeyValuePair<UUID, SceneObjectPart> child in ((SceneObjectGroup) ent).Children)
+                        
+                        SceneObjectGroup sog = ent as SceneObjectGroup;
+                        
+                        lock (sog.Children)
+                        {
+                            foreach (KeyValuePair<UUID, SceneObjectPart> child in (sog.Children))
                             {
                                 if (child.Value.LocalId == primLocalID) 
                                 {
@@ -170,7 +175,10 @@ namespace OpenSim.Region.Framework.Scenes
                                     break;
                                 }
                             }
-                       if (foundPrim) break;
+                        }
+                            
+                        if (foundPrim) 
+                            break;
                    }
                 }
             }

OpenSim/Region/Framework/Scenes/Scene.cs

@@ -1756,8 +1756,9 @@ namespace OpenSim.Region.Framework.Scenes
                 
                 if (group.RootPart == null)
                 {
-                    m_log.ErrorFormat("[SCENE]: Found a SceneObjectGroup with m_rootPart == null and {0} children",
+                    m_log.ErrorFormat(
-                                      group.Children == null ? 0 : group.Children.Count);
+                        "[SCENE]: Found a SceneObjectGroup with m_rootPart == null and {0} children",
+                        group.Children == null ? 0 : group.PrimCount);
                 }
 
                 AddRestoredSceneObject(group, true, true);
@@ -2064,6 +2065,8 @@ namespace OpenSim.Region.Framework.Scenes
                 group.RemoveScriptInstances(true);
             }
 
+            lock (group.Children)
+            {
                 foreach (SceneObjectPart part in group.Children.Values)
                 {
                     if (part.IsJoint() && ((part.Flags & PrimFlags.Physics) != 0))
@@ -2076,6 +2079,8 @@ namespace OpenSim.Region.Framework.Scenes
                         part.PhysActor = null;
                     }
                 }
+            }
+            
 //            if (rootPart.PhysActor != null)
 //            {
 //                PhysicsScene.RemovePrim(rootPart.PhysActor);
@@ -2426,15 +2431,17 @@ namespace OpenSim.Region.Framework.Scenes
 
             // Force allocation of new LocalId
             //
+            lock (sceneObject.Children)
+            {
                 foreach (SceneObjectPart p in sceneObject.Children.Values)
                     p.LocalId = 0;
+            }
 
             if (sceneObject.IsAttachmentCheckFull()) // Attachment
             {
                 sceneObject.RootPart.AddFlag(PrimFlags.TemporaryOnRez);
                 sceneObject.RootPart.AddFlag(PrimFlags.Phantom);
                       
-                      
                 // Don't sent a full update here because this will cause full updates to be sent twice for 
                 // attachments on region crossings, resulting in viewer glitches.                
                 AddRestoredSceneObject(sceneObject, false, false, false);
@@ -2447,7 +2454,6 @@ namespace OpenSim.Region.Framework.Scenes
 
                 if (sp != null)
                 {
-
                     SceneObjectGroup grp = sceneObject;
 
                     m_log.DebugFormat(
@@ -2459,7 +2465,6 @@ namespace OpenSim.Region.Framework.Scenes
                     
                     if (AttachmentsModule != null)
                         AttachmentsModule.AttachObject(sp.ControllingClient, grp, 0, false);
-
                 }
                 else
                 {

OpenSim/Region/Framework/Scenes/SceneGraph.cs

@@ -364,6 +364,8 @@ namespace OpenSim.Region.Framework.Scenes
 //                        "[SCENE GRAPH]: Adding object {0} {1} to region {2}", 
 //                        sceneObject.Name, sceneObject.UUID, m_parentScene.RegionInfo.RegionName);                
             
+                lock (sceneObject.Children)
+                {
                     if (m_parentScene.m_clampPrimSize)
                     {
                         foreach (SceneObjectPart part in sceneObject.Children.Values)
@@ -406,6 +408,7 @@ namespace OpenSim.Region.Framework.Scenes
                         }
                     }
                 }
+            }
 
             return true;
         }
@@ -420,11 +423,16 @@ namespace OpenSim.Region.Framework.Scenes
             {
                 if (!resultOfObjectLinked)
                 {
-                    m_numPrim -= ((SceneObjectGroup) Entities[uuid]).Children.Count;
+                    SceneObjectGroup sog = Entities[uuid] as SceneObjectGroup;
+                    
+                    lock (sog.Children)
+                    {
+                        m_numPrim -= sog.PrimCount;
     
                         if ((((SceneObjectGroup)Entities[uuid]).RootPart.Flags & PrimFlags.Physics) == PrimFlags.Physics)
                         {
-                        RemovePhysicalPrim(((SceneObjectGroup)Entities[uuid]).Children.Count);
+                            RemovePhysicalPrim(sog.PrimCount);
+                        }
                     }
                 }
 
@@ -1603,7 +1611,7 @@ namespace OpenSim.Region.Framework.Scenes
                 {
                     if (part != null)
                     {
-                        if (part.ParentGroup.Children.Count != 1) // Skip single
+                        if (part.ParentGroup.PrimCount != 1) // Skip single
                         {
                             if (part.LinkNum < 2) // Root
                                 rootParts.Add(part);
@@ -1631,8 +1639,15 @@ namespace OpenSim.Region.Framework.Scenes
                     // However, editing linked parts and unlinking may be different
                     //
                     SceneObjectGroup group = root.ParentGroup;
-                    List<SceneObjectPart> newSet = new List<SceneObjectPart>(group.Children.Values);
+                    
-                    int numChildren = group.Children.Count;
+                    List<SceneObjectPart> newSet = null;
+                    int numChildren = -1;
+                    
+                    lock (group.Children)
+                    {
+                        newSet = new List<SceneObjectPart>(group.Children.Values);
+                        numChildren = group.PrimCount;
+                    }
 
                     // If there are prims left in a link set, but the root is
                     // slated for unlink, we need to do this
@@ -1711,7 +1726,11 @@ namespace OpenSim.Region.Framework.Scenes
             {
                 if (ent is SceneObjectGroup)
                 {
-                    foreach (KeyValuePair<UUID, SceneObjectPart> subent in ((SceneObjectGroup)ent).Children)
+                    SceneObjectGroup sog = ent as SceneObjectGroup;
+                    
+                    lock (sog.Children)
+                    {
+                        foreach (KeyValuePair<UUID, SceneObjectPart> subent in sog.Children)
                         {
                             if (subent.Value.LocalId == localID)
                             {
@@ -1721,6 +1740,7 @@ namespace OpenSim.Region.Framework.Scenes
                         }
                     }
                 }
+            }
 
             //Protip: In my day, we didn't call them searchable objects, we called them limited point-to-point joints
             //aka ObjectFlags.JointWheel = IncludeInSearch
@@ -1781,7 +1801,8 @@ namespace OpenSim.Region.Framework.Scenes
             SceneObjectGroup original = GetGroupByPrim(originalPrimID);
             if (original != null)
             {
-                if (m_parentScene.Permissions.CanDuplicateObject(original.Children.Count, original.UUID, AgentID, original.AbsolutePosition))
+                if (m_parentScene.Permissions.CanDuplicateObject(
+                    original.PrimCount, original.UUID, AgentID, original.AbsolutePosition))
                 {
                     SceneObjectGroup copy = original.Copy(true);
                     copy.AbsolutePosition = copy.AbsolutePosition + offset;

OpenSim/Region/Framework/Scenes/SceneObjectGroup.cs

@@ -213,7 +213,7 @@ namespace OpenSim.Region.Framework.Scenes
         /// </summary>
         public int PrimCount
         {
-            get { return m_parts.Count; }
+            get { lock (m_parts) { return m_parts.Count; } }
         }
 
         protected Quaternion m_rotation = Quaternion.Identity;
@@ -237,6 +237,7 @@ namespace OpenSim.Region.Framework.Scenes
 
         /// <value>
         /// The parts of this scene object group.  You must lock this property before using it.
+        /// If you want to know the number of children, consider using the PrimCount property instead
         /// </value>
         public Dictionary<UUID, SceneObjectPart> Children
         {
@@ -298,6 +299,7 @@ namespace OpenSim.Region.Framework.Scenes
                 {
                     m_scene.CrossPrimGroupIntoNewRegion(val, this, true);
                 }
+                
                 if (RootPart.GetStatusSandbox())
                 {
                     if (Util.GetDistanceTo(RootPart.StatusSandboxPos, value) > 10)
@@ -308,6 +310,7 @@ namespace OpenSim.Region.Framework.Scenes
                         return;
                     }
                 }
+                
                 lock (m_parts)
                 {
                     foreach (SceneObjectPart part in m_parts.Values)
@@ -558,7 +561,8 @@ namespace OpenSim.Region.Framework.Scenes
             if (m_rootPart.LocalId == 0)
                 m_rootPart.LocalId = m_scene.AllocateLocalId();
 
-            // No need to lock here since the object isn't yet in a scene
+            lock (m_parts)
+            {
                 foreach (SceneObjectPart part in m_parts.Values)
                 {
                     if (Object.ReferenceEquals(part, m_rootPart))
@@ -574,6 +578,7 @@ namespace OpenSim.Region.Framework.Scenes
                     part.ParentID = m_rootPart.LocalId;
                     //m_log.DebugFormat("[SCENE]: Given local id {0} to part {1}, linknum {2}, parent {3} {4}", part.LocalId, part.UUID, part.LinkNum, part.ParentID, part.ParentUUID);
                 }
+            }
             
             ApplyPhysics(m_scene.m_physicalPrim);
 
@@ -670,7 +675,7 @@ namespace OpenSim.Region.Framework.Scenes
             minY = 256f;
             minZ = 8192f;
 
-            lock(m_parts);
+            lock(m_parts)
             {
                 foreach (SceneObjectPart part in m_parts.Values)
                 {
@@ -995,10 +1000,13 @@ namespace OpenSim.Region.Framework.Scenes
                 m_rootPart.AttachedAvatar = agentID;
 
                 //Anakin Lohner bug #3839 
+                lock (m_parts)
+                {
                     foreach (SceneObjectPart p in m_parts.Values)
                     {
                         p.AttachedAvatar = agentID;
                     }
+                }
 
                 if (m_rootPart.PhysActor != null)
                 {
@@ -1065,11 +1073,15 @@ namespace OpenSim.Region.Framework.Scenes
 
             AbsolutePosition = detachedpos;
             m_rootPart.AttachedAvatar = UUID.Zero;
+            
             //Anakin Lohner bug #3839            
+            lock (m_parts)
+            {
                 foreach (SceneObjectPart p in m_parts.Values)
                 {
                     p.AttachedAvatar = UUID.Zero;
                 }
+            }
 
             m_rootPart.SetParentLocalId(0);
             SetAttachmentPoint((byte)0);
@@ -1094,11 +1106,15 @@ namespace OpenSim.Region.Framework.Scenes
             }
 
             m_rootPart.AttachedAvatar = UUID.Zero;
+            
             //Anakin Lohner bug #3839 
+            lock (m_parts)
+            {
                 foreach (SceneObjectPart p in m_parts.Values)
                 {
                     p.AttachedAvatar = UUID.Zero;
                 }
+            }
 
             m_rootPart.SetParentLocalId(0);
             //m_rootPart.SetAttachmentPoint((byte)0);
@@ -1160,8 +1176,7 @@ namespace OpenSim.Region.Framework.Scenes
                 part.ParentID = 0;
             part.LinkNum = 0;
             
-            // No locking required since the SOG should not be in the scene yet - one can't change root parts after
+            lock (m_parts)
-            // the scene object has been attached to the scene
                 m_parts.Add(m_rootPart.UUID, m_rootPart);
         }
 
@@ -1625,7 +1640,7 @@ namespace OpenSim.Region.Framework.Scenes
         }
 
         /// <summary>
-        ///
+        /// Copy the given part as the root part of this scene object.
         /// </summary>
         /// <param name="part"></param>
         /// <param name="cAgentID"></param>
@@ -1882,11 +1897,12 @@ namespace OpenSim.Region.Framework.Scenes
         /// <param name="cGroupID"></param>
         public SceneObjectPart CopyPart(SceneObjectPart part, UUID cAgentID, UUID cGroupID, bool userExposed)
         {
-            SceneObjectPart newPart = part.Copy(m_scene.AllocateLocalId(), OwnerID, GroupID, m_parts.Count, userExposed);
+            SceneObjectPart newPart = null;
-            newPart.SetParent(this);
             
             lock (m_parts)
             {            
+                newPart = part.Copy(m_scene.AllocateLocalId(), OwnerID, GroupID, m_parts.Count, userExposed);
+                newPart.SetParent(this);
                 m_parts.Add(newPart.UUID, newPart);
             }
 
@@ -1903,8 +1919,8 @@ namespace OpenSim.Region.Framework.Scenes
         /// </summary>
         public void ResetIDs()
         {
-            // As this is only ever called for prims which are not currently part of the scene (and hence
+            lock (m_parts)
-            // not accessible by clients), there should be no need to lock
+            {
                 List<SceneObjectPart> partsList = new List<SceneObjectPart>(m_parts.Values);
                 m_parts.Clear();
                 foreach (SceneObjectPart part in partsList)
@@ -1913,6 +1929,7 @@ namespace OpenSim.Region.Framework.Scenes
                     m_parts.Add(part.UUID, part);
                 }
             }
+        }
 
         /// <summary>
         ///
@@ -2136,10 +2153,15 @@ namespace OpenSim.Region.Framework.Scenes
         public SceneObjectPart GetChildPart(UUID primID)
         {
             SceneObjectPart childPart = null;
+            
+            lock (m_parts)
+            {
                 if (m_parts.ContainsKey(primID))
                 {
                     childPart = m_parts[primID];
                 }
+            }
+            
             return childPart;
         }
 
@@ -2174,8 +2196,9 @@ namespace OpenSim.Region.Framework.Scenes
         /// <returns></returns>
         public bool HasChildPrim(UUID primID)
         {
-            if (m_parts.ContainsKey(primID))
+            lock (m_parts)
             {
+                if (m_parts.ContainsKey(primID))
                     return true;
             }
 
@@ -2370,10 +2393,11 @@ namespace OpenSim.Region.Framework.Scenes
             lock (m_parts)
             {
                 m_parts.Remove(linkPart.UUID);
-            }
                 
                 if (m_parts.Count == 1 && RootPart != null) //Single prim is left
+                {
                     RootPart.LinkNum = 0;
+                }
                 else
                 {
                     foreach (SceneObjectPart p in m_parts.Values)
@@ -2382,6 +2406,7 @@ namespace OpenSim.Region.Framework.Scenes
                             p.LinkNum--;
                     }
                 }                
+            }
 
             linkPart.ParentID = 0;
             linkPart.LinkNum = 0;
@@ -2761,10 +2786,12 @@ namespace OpenSim.Region.Framework.Scenes
 
         public void UpdatePermissions(UUID AgentID, byte field, uint localID,
                 uint mask, byte addRemTF)
+        {
+            lock (m_parts)
             {
                 foreach (SceneObjectPart part in m_parts.Values)
-                part.UpdatePermissions(AgentID, field, localID, mask,
+                    part.UpdatePermissions(AgentID, field, localID, mask, addRemTF);
-                        addRemTF);
+            }
 
             HasGroupChanged = true;
         }

OpenSim/Region/Framework/Scenes/SceneObjectPartInventory.cs

@@ -601,7 +601,10 @@ namespace OpenSim.Region.Framework.Scenes
             rootPart.Name = item.Name;
             rootPart.Description = item.Description;
 
-            List<SceneObjectPart> partList = new List<SceneObjectPart>(group.Children.Values);
+            List<SceneObjectPart> partList = null;
+            
+            lock (group.Children)
+                partList = new List<SceneObjectPart>(group.Children.Values);
 
             group.SetGroup(m_part.GroupID, null);
 

OpenSim/Region/OptionalModules/ContentManagementSystem/CMEntityCollection.cs

@@ -121,6 +121,8 @@ namespace OpenSim.Region.OptionalModules.ContentManagement
                     continue;
                 temp = (SceneObjectGroup) currObj;
 
+                lock (temp.Children)
+                {
                     if (m_CMEntityHash.ContainsKey(temp.UUID))
                     {
                         foreach (SceneObjectPart part in temp.Children.Values)
@@ -133,6 +135,7 @@ namespace OpenSim.Region.OptionalModules.ContentManagement
                             missingList.Add(part);
                     }
                 }
+            }
             return missingList;
         }
 

OpenSim/Region/OptionalModules/ContentManagementSystem/CMModel.cs

@@ -1,4 +1,4 @@
-/*
+/*
  * Copyright (c) Contributors, http://opensimulator.org/
  * See CONTRIBUTORS.TXT for a full list of copyright holders.
  *
@@ -167,10 +167,13 @@ namespace OpenSim.Region.OptionalModules.ContentManagement
         public void RemoveOrUpdateDeletedEntity(SceneObjectGroup group)
         {
             // Deal with new parts not revisioned that have been deleted.
+            lock (group.Children)
+            {
                 foreach (SceneObjectPart part in group.Children.Values)
                     if (m_MetaEntityCollection.Auras.ContainsKey(part.UUID))
                         m_MetaEntityCollection.RemoveNewlyCreatedEntityAura(part.UUID);
             }
+        }
 
         /// <summary>
         /// Retrieves the latest revision of a region in xml form,
@@ -207,8 +210,13 @@ namespace OpenSim.Region.OptionalModules.ContentManagement
                 {
                     temp = SceneObjectSerializer.FromXml2Format(xml);
                     temp.SetScene(scene);
+                    
+                    lock (temp.Children)
+                    {
                         foreach (SceneObjectPart part in temp.Children.Values)
                             part.RegionHandle = scene.RegionInfo.RegionHandle;
+                    }
+                    
                     ReplacementList.Add(temp.UUID, (EntityBase)temp);
                 }
                 catch (Exception e)
@@ -338,6 +346,9 @@ namespace OpenSim.Region.OptionalModules.ContentManagement
             System.Collections.ArrayList auraList = new System.Collections.ArrayList();
             if (group == null)
                 return null;
+            
+            lock (group.Children)
+            {
                 foreach (SceneObjectPart part in group.Children.Values)
                 {
                     if (m_MetaEntityCollection.Auras.ContainsKey(part.UUID))
@@ -347,6 +358,8 @@ namespace OpenSim.Region.OptionalModules.ContentManagement
                         auraList.Add((AuraMetaEntity)m_MetaEntityCollection.Auras[part.UUID]);
                     }
                 }
+            }
+            
             return auraList;
         }
 

OpenSim/Region/OptionalModules/ContentManagementSystem/CMView.cs

@@ -186,10 +186,13 @@ namespace OpenSim.Region.OptionalModules.ContentManagement
                 ((ContentManagementEntity)m_model.MetaEntityCollection.Entities[group.UUID]).SendFullDiffUpdateToAll();
 
             // Deal with new parts not revisioned that have been deleted.
+            lock (group.Children)
+            {
                 foreach (SceneObjectPart part in group.Children.Values)
                     if (m_model.MetaEntityCollection.Auras.ContainsKey(part.UUID))
                         ((AuraMetaEntity)m_model.MetaEntityCollection.Auras[part.UUID]).HideFromAll();
             }
+        }
 
         public void SendMetaEntitiesToNewClient(IClientAPI client)
         {

OpenSim/Region/OptionalModules/ContentManagementSystem/ContentManagementEntity.cs

@@ -1,4 +1,4 @@
-/*
+/*
  * Copyright (c) Contributors, http://opensimulator.org/
  * See CONTRIBUTORS.TXT for a full list of copyright holders.
  *
@@ -131,6 +131,8 @@ namespace OpenSim.Region.OptionalModules.ContentManagement
             DiffersFromSceneGroup = false;
             // if group is not contained in scene's list
             if (!ContainsKey(sceneEntityList, m_UnchangedEntity.UUID))
+            {
+                lock (m_UnchangedEntity.Children)
                 {
                     foreach (SceneObjectPart part in m_UnchangedEntity.Children.Values)
                     {
@@ -157,6 +159,7 @@ namespace OpenSim.Region.OptionalModules.ContentManagement
                         }
                         // otherwise, scene will not contain the part. note: a group can not remove a part without changing group id
                     }
+                }
 
                 // a deleted part has no where to point a beam particle system,
                 // if a metapart had a particle system (maybe it represented a moved part) remove it
@@ -180,8 +183,10 @@ namespace OpenSim.Region.OptionalModules.ContentManagement
         /// </summary>
         public bool HasChildPrim(UUID uuid)
         {
+            lock (m_UnchangedEntity.Children)
                 if (m_UnchangedEntity.Children.ContainsKey(uuid))
                     return true;
+            
             return false;
         }
 
@@ -189,10 +194,14 @@ namespace OpenSim.Region.OptionalModules.ContentManagement
         /// Check if the revisioned scene object group that this CMEntity is based off of contains a child with the given LocalId.
         /// </summary>
         public bool HasChildPrim(uint localID)
+        {
+            lock (m_UnchangedEntity.Children)
             {
                 foreach (SceneObjectPart part in m_UnchangedEntity.Children.Values)
                     if (part.LocalId == localID)
                         return true;
+            }
+            
             return false;
         }
 
@@ -228,6 +237,8 @@ namespace OpenSim.Region.OptionalModules.ContentManagement
             // Use "UnchangedEntity" to do comparisons because its text, transparency, and other attributes will be just as the user
             // had originally saved.
             // m_Entity will NOT necessarily be the same entity as the user had saved.
+            lock (m_UnchangedEntity.Children)
+            {
                 foreach (SceneObjectPart UnchangedPart in m_UnchangedEntity.Children.Values)
                 {
                     //This is the part that we use to show changes.
@@ -309,6 +320,8 @@ namespace OpenSim.Region.OptionalModules.ContentManagement
                         DiffersFromSceneGroup = true;
                     }
                 }
+            }
+            
             return changed;
         }
 

OpenSim/Region/OptionalModules/ContentManagementSystem/MetaEntity.cs

@@ -150,6 +150,9 @@ namespace OpenSim.Region.OptionalModules.ContentManagement
         {
             //make new uuids
             Dictionary<UUID, SceneObjectPart> parts = new Dictionary<UUID, SceneObjectPart>();
+            
+            lock (m_Entity.Children)
+            {
                 foreach (SceneObjectPart part in m_Entity.Children.Values)
                 {
                     part.ResetIDs(part.LinkNum);
@@ -160,6 +163,7 @@ namespace OpenSim.Region.OptionalModules.ContentManagement
                 m_Entity.RootPart.PhysActor = null;
                 m_Entity.Children = parts;                
             }
+        }
 
         #endregion Protected Methods
 
@@ -173,14 +177,19 @@ namespace OpenSim.Region.OptionalModules.ContentManagement
             //This deletes the group without removing from any databases.
             //This is important because we are not IN any database.
             //m_Entity.FakeDeleteGroup();
+            lock (m_Entity.Children)
+            {
                 foreach (SceneObjectPart part in m_Entity.Children.Values)
                     client.SendKillObject(m_Entity.RegionHandle, part.LocalId);
             }
+        }
 
         /// <summary>
         /// Sends a kill object message to all clients, effectively "hiding" the metaentity even though it's still on the server.
         /// </summary>
         public virtual void HideFromAll()
+        {
+            lock (m_Entity.Children)
             {
                 foreach (SceneObjectPart part in m_Entity.Children.Values)
                 {
@@ -190,6 +199,7 @@ namespace OpenSim.Region.OptionalModules.ContentManagement
                     );
                 }
             }
+        }
 
         public void SendFullUpdate(IClientAPI client)
         {

OpenSim/Region/OptionalModules/Scripting/Minimodule/SOPObject.cs

@@ -185,15 +185,20 @@ namespace OpenSim.Region.OptionalModules.Scripting.Minimodule
             get
             {
                 SceneObjectPart my = GetSOP();
+                IObject[] rets = null;
+                
+                lock (my.ParentGroup.Children)
+                {
                     int total = my.ParentGroup.Children.Count;
     
-                IObject[] rets = new IObject[total];
+                    rets = new IObject[total];
     
                     int i = 0;
                     foreach (KeyValuePair<UUID, SceneObjectPart> pair in my.ParentGroup.Children)
                     {
                         rets[i++] = new SOPObject(m_rootScene, pair.Value.LocalId, m_security);
                     }
+                }
 
                 return rets;
             }

OpenSim/Region/ScriptEngine/Shared/Api/Implementation/LSL_Api.cs

@@ -235,7 +235,10 @@ namespace OpenSim.Region.ScriptEngine.Shared.Api
             {
             case ScriptBaseClass.LINK_SET:
                 if (m_host.ParentGroup != null)
+                {
+                    lock (m_host.ParentGroup.Children)
                         return new List<SceneObjectPart>(m_host.ParentGroup.Children.Values);
+                }
                 return ret;
 
             case ScriptBaseClass.LINK_ROOT:
@@ -250,7 +253,10 @@ namespace OpenSim.Region.ScriptEngine.Shared.Api
             case ScriptBaseClass.LINK_ALL_OTHERS:
                 if (m_host.ParentGroup ==  null)
                     return new List<SceneObjectPart>();
+                
+                lock (m_host.ParentGroup.Children)
                     ret = new List<SceneObjectPart>(m_host.ParentGroup.Children.Values);
+                
                 if (ret.Contains(m_host))
                     ret.Remove(m_host);
                 return ret;
@@ -258,7 +264,10 @@ namespace OpenSim.Region.ScriptEngine.Shared.Api
             case ScriptBaseClass.LINK_ALL_CHILDREN:
                 if (m_host.ParentGroup ==  null)
                     return new List<SceneObjectPart>();
+                
+                lock (m_host.ParentGroup.Children)
                     ret = new List<SceneObjectPart>(m_host.ParentGroup.Children.Values);
+                
                 if (ret.Contains(m_host.ParentGroup.RootPart))
                     ret.Remove(m_host.ParentGroup.RootPart);
                 return ret;
@@ -1178,6 +1187,9 @@ namespace OpenSim.Region.ScriptEngine.Shared.Api
                     if (group == null)
                         return;
                     bool allow = true;
+                    
+                    lock (group.Children)
+                    {
                         foreach (SceneObjectPart part in group.Children.Values)
                         {
                             if (part.Scale.X > World.m_maxPhys || part.Scale.Y > World.m_maxPhys || part.Scale.Z > World.m_maxPhys)
@@ -1186,6 +1198,7 @@ namespace OpenSim.Region.ScriptEngine.Shared.Api
                                 break;
                             }
                         }
+                    }
 
                     if (!allow)
                         return;
@@ -3492,7 +3505,7 @@ namespace OpenSim.Region.ScriptEngine.Shared.Api
         {
             m_host.AddScriptLPS(1);
 
-            if (m_host.ParentGroup.Children.Count > 1)
+            if (m_host.ParentGroup.PrimCount > 1)
             {
                 return m_host.LinkNum;
             }
@@ -3604,6 +3617,8 @@ namespace OpenSim.Region.ScriptEngine.Shared.Api
                 case ScriptBaseClass.LINK_ALL_OTHERS:
                 case ScriptBaseClass.LINK_ALL_CHILDREN:
                 case ScriptBaseClass.LINK_THIS:
+                    lock (parentPrim.Children)
+                    {
                         foreach (SceneObjectPart part in parentPrim.Children.Values)
                         {
                             if (part.UUID != m_host.UUID)
@@ -3613,6 +3628,7 @@ namespace OpenSim.Region.ScriptEngine.Shared.Api
                             }
                         }
                         break;
+                    }
                 default:
                     childPrim = parentPrim.GetLinkNumPart(linknum);
                     if (childPrim.UUID == m_host.UUID)
@@ -3623,6 +3639,8 @@ namespace OpenSim.Region.ScriptEngine.Shared.Api
             if (linknum == ScriptBaseClass.LINK_ROOT)
             {
                 // Restructuring Multiple Prims.
+                lock (parentPrim.Children)
+                {
                     List<SceneObjectPart> parts = new List<SceneObjectPart>(parentPrim.Children.Values);
                     parts.Remove(parentPrim.RootPart);
                     foreach (SceneObjectPart part in parts)
@@ -3646,6 +3664,7 @@ namespace OpenSim.Region.ScriptEngine.Shared.Api
                         newRoot.ParentGroup.ScheduleGroupForFullUpdate();
                     }
                 }
+            }
             else
             {
                 if (childPrim == null)
@@ -3665,6 +3684,8 @@ namespace OpenSim.Region.ScriptEngine.Shared.Api
             if (parentPrim.RootPart.AttachmentPoint != 0)
                 return; // Fail silently if attached
 
+            lock (parentPrim.Children)
+            {
                 List<SceneObjectPart> parts = new List<SceneObjectPart>(parentPrim.Children.Values);
                 parts.Remove(parentPrim.RootPart);
     
@@ -3676,6 +3697,7 @@ namespace OpenSim.Region.ScriptEngine.Shared.Api
                 parentPrim.HasGroupChanged = true;
                 parentPrim.ScheduleGroupForFullUpdate();
             }
+        }
 
         public LSL_String llGetLinkKey(int linknum)
         {
@@ -4200,7 +4222,7 @@ namespace OpenSim.Region.ScriptEngine.Shared.Api
                     {
                         partItemID = item.ItemID;
                         int linkNumber = m_host.LinkNum;
-                        if (m_host.ParentGroup.Children.Count == 1)
+                        if (m_host.ParentGroup.PrimCount == 1)
                             linkNumber = 0;
 
                         object[] resobj = new object[]

OpenSim/Region/ScriptEngine/Shared/Helpers.cs

@@ -209,6 +209,8 @@ namespace OpenSim.Region.ScriptEngine.Shared
             else
                 Type = 0x02; // Passive
 
+            lock (part.ParentGroup.Children)
+            {
                 foreach (SceneObjectPart p in part.ParentGroup.Children.Values)
                 {
                     if (p.Inventory.ContainsScripts())
@@ -217,6 +219,7 @@ namespace OpenSim.Region.ScriptEngine.Shared
                         break;
                     }
                 }
+            }
 
             Position = new LSL_Types.Vector3(part.AbsolutePosition.X,
                                              part.AbsolutePosition.Y,