* Stop nulling SOG.m_rootPart and parts on object deletion

* This renders RootPart == null checks useless - the replacement is to check SOG.IsDeleted.  However, in many cases this will not be necessary since updates to deleted parts 
will not be sent to the client
* This should remove any remaining race conditions where an object is deleted while another thread is yet to obtain the root part to perform some operation
* Doing this is probably a necessary prerequisite to moving to a model without a separate SOG and SOP
* Unfortunately it's not possible to eliminate all RootPart == null checks since in some contexts it is currently used to check whether an object was created successfully

6 files changed, 27 insertions, 31 deletions

diff --git a/OpenSim/Region/Environment/Scenes/AsyncSceneObjectGroupDeleter.cs b/OpenSim/Region/Environment/Scenes/AsyncSceneObjectGroupDeleter.cs
index 706ba6a..442b40d 100644
--- a/OpenSim/Region/Environment/Scenes/AsyncSceneObjectGroupDeleter.cs
+++ b/OpenSim/Region/Environment/Scenes/AsyncSceneObjectGroupDeleter.cs
@@ -126,7 +126,7 @@ namespace OpenSim.Region.Environment.Scenes
                             "[SCENE]: Sending deleted object to user's inventory, {0} item(s) remaining.", left);
                         
                         x = m_inventoryDeletes.Dequeue();
-                        if (x.objectGroup.RootPart != null)
+                        if (!x.objectGroup.IsDeleted)
                         {
                             try
                             {
diff --git a/OpenSim/Region/Environment/Scenes/Scene.Inventory.cs b/OpenSim/Region/Environment/Scenes/Scene.Inventory.cs
index 9ad8382..cc8501d 100644
--- a/OpenSim/Region/Environment/Scenes/Scene.Inventory.cs
+++ b/OpenSim/Region/Environment/Scenes/Scene.Inventory.cs
@@ -1552,7 +1552,7 @@ namespace OpenSim.Region.Environment.Scenes
             if (part == null)
                 return;
 
-            if (part.ParentGroup == null || part.ParentGroup.RootPart == null)
+            if (part.ParentGroup == null || part.ParentGroup.IsDeleted)
                 return;
 
             // Can't delete child prims
@@ -2379,7 +2379,7 @@ namespace OpenSim.Region.Environment.Scenes
         public UUID RezSingleAttachment(SceneObjectGroup att,
                 IClientAPI remoteClient, UUID itemID, uint AttachmentPt)
         {
-            if (att.RootPart != null)
+            if (!att.IsDeleted)
                 AttachmentPt = att.RootPart.AttachmentPoint;
 
             ScenePresence presence;
diff --git a/OpenSim/Region/Environment/Scenes/Scene.cs b/OpenSim/Region/Environment/Scenes/Scene.cs
index c055160..cf743de 100644
--- a/OpenSim/Region/Environment/Scenes/Scene.cs
+++ b/OpenSim/Region/Environment/Scenes/Scene.cs
@@ -2015,7 +2015,7 @@ namespace OpenSim.Region.Environment.Scenes
         {
             if (grp == null)
                 return;
-            if (grp.RootPart == null)
+            if (grp.IsDeleted)
                 return;
 
             if (grp.RootPart.DIE_AT_EDGE)
@@ -2116,7 +2116,7 @@ namespace OpenSim.Region.Environment.Scenes
                 }
                 else
                 {
-                    if (grp.RootPart != null)
+                    if (!grp.IsDeleted)
                     {
                         if (grp.RootPart.PhysActor != null)
                         {
@@ -2688,7 +2688,7 @@ namespace OpenSim.Region.Environment.Scenes
             SceneObjectPart part = GetSceneObjectPart(localID);
             if (part != null) // It is a prim
             {
-                if (part.ParentGroup != null && part.ParentGroup.RootPart != null) // Valid
+                if (part.ParentGroup != null && !part.ParentGroup.IsDeleted) // Valid
                 {
                     if (part.ParentGroup.RootPart != part) // Child part
                         return;
@@ -4200,7 +4200,7 @@ namespace OpenSim.Region.Environment.Scenes
             if (part == null || part.ParentGroup == null)
                 return;
 
-            if (part.ParentGroup.RootPart == null)
+            if (part.ParentGroup.IsDeleted)
                 return;
 
             part = part.ParentGroup.RootPart;
@@ -4366,7 +4366,7 @@ namespace OpenSim.Region.Environment.Scenes
                 {
                     SceneObjectGroup grp = (SceneObjectGroup)obj;
 
-                    if (grp.RootPart != null)
+                    if (!grp.IsDeleted)
                     {
                         if ((grp.RootPart.Flags & PrimFlags.TemporaryOnRez) != 0)
                         {
diff --git a/OpenSim/Region/Environment/Scenes/SceneObjectGroup.cs b/OpenSim/Region/Environment/Scenes/SceneObjectGroup.cs
index 0af2ad2..36b4e10 100644
--- a/OpenSim/Region/Environment/Scenes/SceneObjectGroup.cs
+++ b/OpenSim/Region/Environment/Scenes/SceneObjectGroup.cs
@@ -1035,9 +1035,6 @@ namespace OpenSim.Region.Environment.Scenes
         public void DeleteGroup(bool silent)
         {
             // We need to keep track of this state in case this group is still queued for backup.
-            // FIXME: This is a poor temporary solution, since it still leaves plenty of scope for race
-            // conditions where a user deletes an entity while it is being stored.  Really, the update
-            // code needs a redesign.
             m_isDeleted = true;
 
             DetachFromBackup();
@@ -1063,9 +1060,6 @@ namespace OpenSim.Region.Environment.Scenes
                         }
                     }
                 }
-
-                m_rootPart = null;
-                m_parts.Clear();
             }
         }
 
@@ -1228,7 +1222,7 @@ namespace OpenSim.Region.Environment.Scenes
             // Since this is the top of the section of call stack for backing up a particular scene object, don't let
             // any exception propogate upwards.
 
-            if (RootPart == null || UUID == UUID.Zero)
+            if (IsDeleted || UUID == UUID.Zero)
             {
 //                DetachFromBackup();
                 return;
@@ -1932,8 +1926,8 @@ namespace OpenSim.Region.Environment.Scenes
             }
 
             m_scene.UnlinkSceneObject(objectGroup.UUID, true);
-            objectGroup.Children.Clear();
-            objectGroup.m_rootPart = null;
+//            objectGroup.Children.Clear();
+//            objectGroup.m_rootPart = null;
 
             // TODO Deleting the original group object may cause problems later on if they have already
             // made it into the update queue.  However, sending out updates for those parts is now
@@ -2803,6 +2797,7 @@ namespace OpenSim.Region.Environment.Scenes
                 }
             }
         }
+        
         public float GetMass()
         {
             float retmass = 0f;
@@ -2815,11 +2810,12 @@ namespace OpenSim.Region.Environment.Scenes
             }
             return retmass;
         }
+        
         public void CheckSculptAndLoad()
         {
             lock (m_parts)
             {
-                if (RootPart != null)
+                if (!IsDeleted)
                 {
                     if ((RootPart.GetEffectiveObjectFlags() & (uint)PrimFlags.Phantom) == 0)
                     {
diff --git a/OpenSim/Region/Environment/Scenes/SceneObjectPart.cs b/OpenSim/Region/Environment/Scenes/SceneObjectPart.cs
index a02840c..74fa725 100644
--- a/OpenSim/Region/Environment/Scenes/SceneObjectPart.cs
+++ b/OpenSim/Region/Environment/Scenes/SceneObjectPart.cs
@@ -492,7 +492,7 @@ namespace OpenSim.Region.Environment.Scenes
                 StoreUndoState();
                 m_offsetPosition = value;
 
-                if (ParentGroup != null && ParentGroup.RootPart != null)
+                if (ParentGroup != null && !ParentGroup.IsDeleted)
                 {
                      if (_parentID != 0 && PhysActor != null)
                     {
@@ -1326,7 +1326,7 @@ if (m_shape != null) {
         {
             if (m_parentGroup == null)
                 return false;
-            if (m_parentGroup.RootPart == null)
+            if (m_parentGroup.IsDeleted)
                 return false;
 
             return m_parentGroup.RootPart.DIE_AT_EDGE;
@@ -1604,7 +1604,7 @@ if (m_shape != null) {
             }
             if (m_parentGroup == null)
                 return;
-            if (m_parentGroup.RootPart == null)
+            if (m_parentGroup.IsDeleted)
                 return;
 
             if ((m_parentGroup.RootPart.ScriptEvents & scriptEvents.collision_start) != 0)
@@ -2251,7 +2251,7 @@ if (m_shape != null) {
         {
             if (m_parentGroup == null)
                 return;
-            if (m_parentGroup.RootPart == null)
+            if (m_parentGroup.IsDeleted)
                 return;
 
             m_parentGroup.RootPart.DIE_AT_EDGE = p;
@@ -3022,7 +3022,7 @@ if (m_shape != null) {
                     DoPhysicsPropertyUpdate(UsePhysics, false);
                     if (m_parentGroup != null)
                     {
-                        if (m_parentGroup.RootPart != null)
+                        if (!m_parentGroup.IsDeleted)
                         {
                             if (LocalId == m_parentGroup.RootPart.LocalId)
                             {
@@ -3070,7 +3070,7 @@ if (m_shape != null) {
                         DoPhysicsPropertyUpdate(UsePhysics, true);
                         if (m_parentGroup != null)
                         {
-                            if (m_parentGroup.RootPart != null)
+                            if (!m_parentGroup.IsDeleted)
                             {
                                 if (LocalId == m_parentGroup.RootPart.LocalId)
                                 {
@@ -3086,7 +3086,7 @@ if (m_shape != null) {
                     DoPhysicsPropertyUpdate(UsePhysics, false);
                     if (m_parentGroup != null)
                     {
-                        if (m_parentGroup.RootPart != null)
+                        if (!m_parentGroup.IsDeleted)
                         {
                             if (LocalId == m_parentGroup.RootPart.LocalId)
                             {
@@ -3341,7 +3341,7 @@ if (m_shape != null) {
 
         public void SendTerseUpdateToClient(IClientAPI remoteClient)
         {
-            if (ParentGroup == null || ParentGroup.RootPart == null)
+            if (ParentGroup == null || ParentGroup.IsDeleted)
                 return;
 
             Vector3 lPos = OffsetPosition;
diff --git a/OpenSim/Region/Environment/Scenes/ScenePresence.cs b/OpenSim/Region/Environment/Scenes/ScenePresence.cs
index c91027c..935c51b 100644
--- a/OpenSim/Region/Environment/Scenes/ScenePresence.cs
+++ b/OpenSim/Region/Environment/Scenes/ScenePresence.cs
@@ -637,8 +637,10 @@ namespace OpenSim.Region.Environment.Scenes
             while (m_partsUpdateQueue.Count > 0)
             {
                 SceneObjectPart part = m_partsUpdateQueue.Dequeue();
-                if (part.ParentGroup == null || part.ParentGroup.RootPart == null)
+                
+                if (part.ParentGroup == null || part.ParentGroup.IsDeleted)
                     continue;
+                
                 if (m_updateTimes.ContainsKey(part.UUID))
                 {
                     ScenePartUpdate update = m_updateTimes[part.UUID];
@@ -2582,10 +2584,8 @@ namespace OpenSim.Region.Environment.Scenes
                     if (gobj == null)
                         return false;
 
-                    if (gobj.RootPart == null)
-                    {
+                    if (gobj.IsDeleted)
                         return false;
-                    }
                 }
             }
             return true;
@@ -2598,7 +2598,7 @@ namespace OpenSim.Region.Environment.Scenes
                 // Validate
                 foreach (SceneObjectGroup gobj in m_attachments)
                 {
-                    if (gobj == null || gobj.RootPart == null)
+                    if (gobj == null || gobj.IsDeleted)
                         return false;
                 }