Make SP.Attachments available as sp.GetAttachments() instead.

The approach here, as in other parts of OpenSim, is to return a copy of the list rather than the attachments list itself
This prevents callers from forgetting to lock the list when they read it, as was happening in various parts of the codebase.
It also improves liveness.
This might improve attachment anomolies when performing region crossings.

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

@@ -136,10 +136,7 @@ namespace OpenSim.Region.CoreModules.Avatar.Attachments
 
         public void SaveChangedAttachments(IScenePresence sp)
         {
-            // Need to copy this list because DetachToInventoryPrep mods it
+            foreach (SceneObjectGroup grp in sp.GetAttachments())
-            List<SceneObjectGroup> attachments = new List<SceneObjectGroup>(sp.Attachments);
-
-            foreach (SceneObjectGroup grp in attachments)
             {
                 if (grp.HasGroupChanged) // Resizer scripts?
                 {
@@ -273,14 +270,12 @@ namespace OpenSim.Region.CoreModules.Avatar.Attachments
 
             // Remove any previous attachments
             UUID itemID = UUID.Zero;
-            foreach (SceneObjectGroup grp in sp.Attachments)
+
-            {
+            List<SceneObjectGroup> attachments = sp.GetAttachments(attachmentPt);
-                if (grp.AttachmentPoint == attachmentPt)
+
-                {
+            // At the moment we can only deal with a single attachment
-                    itemID = grp.GetFromItemID();
+            if (attachments.Count != 0)
-                    break;
+                itemID = attachments[0].GetFromItemID();
-                }
-            }
 
             if (itemID != UUID.Zero)
                 DetachSingleAttachmentToInv(itemID, sp);

OpenSim/Region/CoreModules/Avatar/Attachments/Tests/AttachmentsModuleTests.cs

@@ -106,7 +106,7 @@ namespace OpenSim.Region.CoreModules.Avatar.Attachments.Tests
 
             // Check status on scene presence
             Assert.That(m_presence.HasAttachments(), Is.True);
-            List<SceneObjectGroup> attachments = m_presence.Attachments;
+            List<SceneObjectGroup> attachments = m_presence.GetAttachments();
             Assert.That(attachments.Count, Is.EqualTo(1));
             SceneObjectGroup attSo = attachments[0];
             Assert.That(attSo.Name, Is.EqualTo(attName));
@@ -140,7 +140,7 @@ namespace OpenSim.Region.CoreModules.Avatar.Attachments.Tests
 
             // Check scene presence status
             Assert.That(m_presence.HasAttachments(), Is.True);
-            List<SceneObjectGroup> attachments = m_presence.Attachments;
+            List<SceneObjectGroup> attachments = m_presence.GetAttachments();
             Assert.That(attachments.Count, Is.EqualTo(1));
             SceneObjectGroup attSo = attachments[0];
             Assert.That(attSo.Name, Is.EqualTo(attName));
@@ -174,7 +174,7 @@ namespace OpenSim.Region.CoreModules.Avatar.Attachments.Tests
 
             // Check scene presence status
             Assert.That(m_presence.HasAttachments(), Is.False);
-            List<SceneObjectGroup> attachments = m_presence.Attachments;
+            List<SceneObjectGroup> attachments = m_presence.GetAttachments();
             Assert.That(attachments.Count, Is.EqualTo(0));
 
             // Check appearance status
@@ -208,7 +208,7 @@ namespace OpenSim.Region.CoreModules.Avatar.Attachments.Tests
 
             // Check status on scene presence
             Assert.That(m_presence.HasAttachments(), Is.False);
-            List<SceneObjectGroup> attachments = m_presence.Attachments;
+            List<SceneObjectGroup> attachments = m_presence.GetAttachments();
             Assert.That(attachments.Count, Is.EqualTo(0));
 
             // Check item status
@@ -237,7 +237,7 @@ namespace OpenSim.Region.CoreModules.Avatar.Attachments.Tests
             ScenePresence presence = SceneHelpers.AddScenePresence(scene, acd);
 
             Assert.That(presence.HasAttachments(), Is.True);
-            List<SceneObjectGroup> attachments = presence.Attachments;
+            List<SceneObjectGroup> attachments = presence.GetAttachments();
 
             Assert.That(attachments.Count, Is.EqualTo(1));
             SceneObjectGroup attSo = attachments[0];

OpenSim/Region/CoreModules/Framework/EntityTransfer/EntityTransferModule.cs

@@ -208,7 +208,7 @@ namespace OpenSim.Region.CoreModules.Framework.EntityTransfer
                     sp.ControllingClient.SendLocalTeleport(position, lookAt, teleportFlags);
                     sp.Teleport(position);
 
-                    foreach (SceneObjectGroup grp in sp.Attachments)
+                    foreach (SceneObjectGroup grp in sp.GetAttachments())
                         sp.Scene.EventManager.TriggerOnScriptChangedEvent(grp.LocalId, (uint)Changed.TELEPORT);
                 }
                 else // Another region possibly in another simulator
@@ -559,11 +559,11 @@ namespace OpenSim.Region.CoreModules.Framework.EntityTransfer
 
         protected virtual void AgentHasMovedAway(ScenePresence sp, bool logout)
         {
-            foreach (SceneObjectGroup sop in sp.Attachments)
+            foreach (SceneObjectGroup sop in sp.GetAttachments())
             {
                 sop.Scene.DeleteSceneObject(sop, true);
             }
-            sp.Attachments.Clear();
+            sp.ClearAttachments();
         }
 
         protected void KillEntity(Scene scene, uint localID)
@@ -1764,9 +1764,8 @@ namespace OpenSim.Region.CoreModules.Framework.EntityTransfer
 
         protected bool CrossAttachmentsIntoNewRegion(GridRegion destination, ScenePresence sp, bool silent)
         {
-            List<SceneObjectGroup> m_attachments = sp.Attachments;
+            List<SceneObjectGroup> m_attachments = sp.GetAttachments();
-            lock (m_attachments)
+
-            {
             // Validate
             foreach (SceneObjectGroup gobj in m_attachments)
             {
@@ -1788,11 +1787,11 @@ namespace OpenSim.Region.CoreModules.Framework.EntityTransfer
                     CrossPrimGroupIntoNewRegion(destination, gobj, silent);
                 }
             }
-                m_attachments.Clear();
+
+            sp.ClearAttachments();
 
             return true;
         }
-        }
 
         #endregion
 
@@ -1840,7 +1839,9 @@ namespace OpenSim.Region.CoreModules.Framework.EntityTransfer
             int i = 0;
             if (sp.InTransitScriptStates.Count > 0)
             {
-                sp.Attachments.ForEach(delegate(SceneObjectGroup sog)
+                List<SceneObjectGroup> attachments = sp.GetAttachments();
+
+                foreach (SceneObjectGroup sog in attachments)
                 {
                     if (i < sp.InTransitScriptStates.Count)
                     {
@@ -1849,8 +1850,10 @@ namespace OpenSim.Region.CoreModules.Framework.EntityTransfer
                         sog.ResumeScripts();
                     }
                     else
-                        m_log.ErrorFormat("[ENTITY TRANSFER MODULE]: InTransitScriptStates.Count={0} smaller than Attachments.Count={1}", sp.InTransitScriptStates.Count, sp.Attachments.Count);
+                        m_log.ErrorFormat(
-                });
+                            "[ENTITY TRANSFER MODULE]: InTransitScriptStates.Count={0} smaller than Attachments.Count={1}",
+                            sp.InTransitScriptStates.Count, attachments.Count);
+                }
 
                 sp.InTransitScriptStates.Clear();
             }

OpenSim/Region/CoreModules/Scripting/WorldComm/WorldCommModule.cs

@@ -283,7 +283,7 @@ namespace OpenSim.Region.CoreModules.Scripting.WorldComm
         }
 
         /// <summary>
-        /// Delivers the message to.
+        /// Delivers the message to a scene entity.
         /// </summary>
         /// <param name='target'>
         /// Target.
@@ -314,17 +314,19 @@ namespace OpenSim.Region.CoreModules.Scripting.WorldComm
                     m_scene.SimChatBroadcast(Utils.StringToBytes(msg), ChatTypeEnum.Owner, 0, pos, name, id, false);
                 }
 
-                List<SceneObjectGroup> attachments = sp.Attachments;
+                List<SceneObjectGroup> attachments = sp.GetAttachments();
+
                 // Nothing left to do
                 if (attachments == null)
                     return true;
 
                 // Get uuid of attachments
                 List<UUID> targets = new List<UUID>();
-                foreach ( SceneObjectGroup sog in attachments )
+                foreach (SceneObjectGroup sog in attachments)
                 {
                     targets.Add(sog.UUID);
                 }
+
                 // Need to check each attachment
                 foreach (ListenerInfo li in m_listenerManager.GetListeners(UUID.Zero, channel, name, id, msg))
                 {
@@ -334,9 +336,10 @@ namespace OpenSim.Region.CoreModules.Scripting.WorldComm
                     if (m_scene.GetSceneObjectPart(li.GetHostID()) == null)
                         continue;
 
-                    if ( targets.Contains(li.GetHostID()))
+                    if (targets.Contains(li.GetHostID()))
                         QueueMessage(new ListenerInfo(li, name, id, msg));
                 }
+
                 return true;
             }
 
@@ -363,6 +366,7 @@ namespace OpenSim.Region.CoreModules.Scripting.WorldComm
                     break;
                 }
             }
+            
             return true;
         }
 

OpenSim/Region/Framework/Interfaces/IScenePresence.cs

@@ -58,10 +58,13 @@ namespace OpenSim.Region.Framework.Interfaces
         /// <summary>
         /// The scene objects attached to this avatar.
         /// </summary>
+        /// <returns>
+        /// A copy of the list.
+        /// </returns>
         /// <remarks>
         ///  Do not change this list directly - use methods such as
-        /// AddAttachment() and RemoveAttachment().  Lock this list when performing any read operations upon it.
+        /// AddAttachment() and RemoveAttachment().
         /// </remarks>
-        List<SceneObjectGroup> Attachments { get; }
+        List<SceneObjectGroup> GetAttachments();
     }
 }

OpenSim/Region/Framework/Scenes/ScenePresence.cs

@@ -114,10 +114,13 @@ namespace OpenSim.Region.Framework.Scenes
         }
         protected ScenePresenceAnimator m_animator;
 
-        public List<SceneObjectGroup> Attachments
+        /// <summary>
-        {
+        /// Attachments recorded on this avatar.
-            get { return m_attachments; }
+        /// </summary>
-        }
+        /// <remarks>
+        /// TODO: For some reason, we effectively have a list both here and in Appearance.  Need to work out if this is
+        /// necessary.
+        /// </remarks>
         protected List<SceneObjectGroup> m_attachments = new List<SceneObjectGroup>();
 
         private Dictionary<UUID, ScriptControllers> scriptedcontrols = new Dictionary<UUID, ScriptControllers>();
@@ -940,15 +943,18 @@ namespace OpenSim.Region.Framework.Scenes
             // and it has already rezzed the attachments and started their scripts.
             // We do the following only for non-login agents, because their scripts
             // haven't started yet.
-            if (wasChild && Attachments != null && Attachments.Count > 0)
+            lock (m_attachments)
+            {
+                if (wasChild && m_attachments != null && m_attachments.Count > 0)
                 {
                     m_log.DebugFormat("[SCENE PRESENCE]: Restarting scripts in attachments...");
                     // Resume scripts
-                Attachments.ForEach(delegate(SceneObjectGroup sog)
+                    foreach (SceneObjectGroup sog in m_attachments)
                     {
                         sog.RootPart.ParentGroup.CreateScriptInstances(0, false, m_scene.DefaultScriptEngine, GetStateSource());
                         sog.ResumeScripts();
-                });
+                    }
+                }
             }
 
             // send the animations of the other presences to me
@@ -3474,7 +3480,17 @@ namespace OpenSim.Region.Framework.Scenes
         }
 
         /// <summary>
-        /// Get the scene object attached to the given point.
+        /// Get all the presence's attachments.
+        /// </summary>
+        /// <returns>A copy of the list which contains the attachments.</returns>
+        public List<SceneObjectGroup> GetAttachments()
+        {
+            lock (m_attachments)
+                return new List<SceneObjectGroup>(m_attachments);
+        }
+
+        /// <summary>
+        /// Get the scene objects attached to the given point.
         /// </summary>
         /// <param name="attachmentPoint"></param>
         /// <returns>Returns an empty list if there were no attachments at the point.</returns>
@@ -3521,6 +3537,15 @@ namespace OpenSim.Region.Framework.Scenes
                 m_attachments.Remove(gobj);
         }
 
+        /// <summary>
+        /// Clear all attachments
+        /// </summary>
+        public void ClearAttachments()
+        {
+            lock (m_attachments)
+                m_attachments.Clear();
+        }
+
         public bool ValidateAttachments()
         {
             lock (m_attachments)

OpenSim/Region/OptionalModules/World/NPC/NPCModule.cs

@@ -144,14 +144,10 @@ namespace OpenSim.Region.OptionalModules.World.NPC
                     return false;
 
             // FIXME: An extremely bad bit of code that reaches directly into the attachments list and manipulates it
-            List<SceneObjectGroup> attachments = sp.Attachments;
+            foreach (SceneObjectGroup att in sp.GetAttachments())
-            lock (attachments)
-            {
-                foreach (SceneObjectGroup att in attachments)
                 scene.DeleteSceneObject(att, false);
 
-                attachments.Clear();
+            sp.ClearAttachments();
-            }
 
             AvatarAppearance npcAppearance = new AvatarAppearance(appearance, true);
             sp.Appearance = npcAppearance;