1 files changed, 53 insertions, 28 deletions

diff --git a/OpenSim/Region/CoreModules/Avatar/Friends/FriendsModule.cs b/OpenSim/Region/CoreModules/Avatar/Friends/FriendsModule.cs
index 0c81bb2..5d94ff7 100644
--- a/OpenSim/Region/CoreModules/Avatar/Friends/FriendsModule.cs
+++ b/OpenSim/Region/CoreModules/Avatar/Friends/FriendsModule.cs
@@ -29,6 +29,7 @@ using System;
 using System.Collections;
 using System.Collections.Generic;
 using System.Reflection;
+using System.Threading;
 using log4net;
 using Nini.Config;
 using Nwc.XmlRpc;
@@ -79,10 +80,20 @@ namespace OpenSim.Region.CoreModules.Avatar.Friends
         protected IFriendsService m_FriendsService = null;
         protected FriendsSimConnector m_FriendsSimConnector;
 
-        protected Dictionary<UUID, UserFriendData> m_Friends =
-                new Dictionary<UUID, UserFriendData>();
+        /// <summary>
+        /// Cache friends lists for users.
+        /// </summary>
+        /// <remarks>
+        /// This is a complex and error-prone thing to do.  At the moment, we assume that the efficiency gained in
+        /// permissions checks outweighs the disadvantages of that complexity.
+        /// </remarks>
+        protected Dictionary<UUID, UserFriendData> m_Friends = new Dictionary<UUID, UserFriendData>();
 
-        protected HashSet<UUID> m_NeedsListOfFriends = new HashSet<UUID>();
+        /// <summary>
+        /// Maintain a record of viewers that need to be sent notifications for friends that are online.  This only
+        /// needs to be done on login.  Subsequent online/offline friend changes are sent by a different mechanism.
+        /// </summary>
+        protected HashSet<UUID> m_NeedsListOfOnlineFriends = new HashSet<UUID>();
 
         protected IPresenceService PresenceService
         {
@@ -189,6 +200,7 @@ namespace OpenSim.Region.CoreModules.Avatar.Friends
         {
             if (!m_Enabled)
                 return;
+
             m_log.DebugFormat("[FRIENDS MODULE]: AddRegion on {0}", Name);
 
             m_Scenes.Add(scene);
@@ -241,16 +253,25 @@ namespace OpenSim.Region.CoreModules.Avatar.Friends
             client.OnInstantMessage += OnInstantMessage;
             client.OnApproveFriendRequest += OnApproveFriendRequest;
             client.OnDenyFriendRequest += OnDenyFriendRequest;
-            client.OnTerminateFriendship += OnTerminateFriendship;
+            client.OnTerminateFriendship += (thisClient, agentID, exfriendID) => RemoveFriendship(thisClient, exfriendID);
             client.OnGrantUserRights += OnGrantUserRights;
 
-            Util.FireAndForget(delegate { FetchFriendslist(client); });
+            // Do not do this asynchronously.  If we do, then subsequent code can outrace CacheFriends() and
+            // return misleading results from the still empty friends cache.
+            // If we absolutely need to do this asynchronously, then a signalling mechanism is needed so that calls
+            // to GetFriends() will wait until CacheFriends() completes.  Locks are insufficient.
+            CacheFriends(client);
         }
 
-        /// Fetch the friends list or increment the refcount for the existing 
-        /// friends list
+        /// <summary>
+        /// Cache the friends list or increment the refcount for the existing friends list.
+        /// </summary>
+        /// <param name="client">
+        /// </param>
+        /// <returns>
         /// Returns true if the list was fetched, false if it wasn't
-        protected virtual bool FetchFriendslist(IClientAPI client)
+        /// </returns>
+        protected virtual bool CacheFriends(IClientAPI client)
         {
             UUID agentID = client.AgentId;
             lock (m_Friends)
@@ -297,7 +318,7 @@ namespace OpenSim.Region.CoreModules.Avatar.Friends
 
         private void OnMakeRootAgent(ScenePresence sp)
         {
-            RefetchFriends(sp.ControllingClient);
+            RecacheFriends(sp.ControllingClient);
         }
 
         private void OnClientLogin(IClientAPI client)
@@ -309,8 +330,8 @@ namespace OpenSim.Region.CoreModules.Avatar.Friends
             StatusChange(agentID, true);
 
             // Register that we need to send the list of online friends to this user
-            lock (m_NeedsListOfFriends)
-                m_NeedsListOfFriends.Add(agentID);
+            lock (m_NeedsListOfOnlineFriends)
+                m_NeedsListOfOnlineFriends.Add(agentID);
         }
 
         public virtual bool SendFriendsOnlineIfNeeded(IClientAPI client)
@@ -318,9 +339,9 @@ namespace OpenSim.Region.CoreModules.Avatar.Friends
             UUID agentID = client.AgentId;
 
             // Check if the online friends list is needed
-            lock (m_NeedsListOfFriends)
+            lock (m_NeedsListOfOnlineFriends)
             {
-                if (!m_NeedsListOfFriends.Remove(agentID))
+                if (!m_NeedsListOfOnlineFriends.Remove(agentID))
                     return false;
             }
 
@@ -328,7 +349,10 @@ namespace OpenSim.Region.CoreModules.Avatar.Friends
             List<UUID> online = GetOnlineFriends(agentID);
             if (online.Count > 0)
             {
-                m_log.DebugFormat("[FRIENDS MODULE]: User {0} in region {1} has {2} friends online", client.AgentId, client.Scene.RegionInfo.RegionName, online.Count);
+                m_log.DebugFormat(
+                    "[FRIENDS MODULE]: User {0} in region {1} has {2} friends online",
+                    client.Name, client.Scene.RegionInfo.RegionName, online.Count);
+
                 client.SendAgentOnline(online.ToArray());
             }
 
@@ -586,7 +610,7 @@ namespace OpenSim.Region.CoreModules.Avatar.Friends
             }
 
             // Update the local cache
-            RefetchFriends(client);
+            RecacheFriends(client);
 
             //
             // Notify the friend
@@ -641,14 +665,14 @@ namespace OpenSim.Region.CoreModules.Avatar.Friends
                 }
             }
         }
-
-        private void OnTerminateFriendship(IClientAPI client, UUID agentID, UUID exfriendID)
+        
+        public void RemoveFriendship(IClientAPI client, UUID exfriendID)
         {
-            if (!DeleteFriendship(agentID, exfriendID))
+            if (!DeleteFriendship(client.AgentId, exfriendID))
                 client.SendAlertMessage("Unable to terminate friendship on this sim.");
 
             // Update local cache
-            RefetchFriends(client);
+            RecacheFriends(client);
 
             client.SendTerminateFriend(exfriendID);
 
@@ -667,9 +691,9 @@ namespace OpenSim.Region.CoreModules.Avatar.Friends
                 if (friendSession != null)
                 {
                     GridRegion region = GridService.GetRegionByUUID(m_Scenes[0].RegionInfo.ScopeID, friendSession.RegionID);
-                    m_FriendsSimConnector.FriendshipTerminated(region, agentID, exfriendID);
+                    m_FriendsSimConnector.FriendshipTerminated(region, client.AgentId, exfriendID);
                 }
-            }
+            }            
         }
 
         private void OnGrantUserRights(IClientAPI remoteClient, UUID requester, UUID target, int rights)
@@ -769,7 +793,7 @@ namespace OpenSim.Region.CoreModules.Avatar.Friends
 
 
                 // Update the local cache
-                RefetchFriends(friendClient);
+                RecacheFriends(friendClient);
 
                 // we're done
                 return true;
@@ -802,7 +826,7 @@ namespace OpenSim.Region.CoreModules.Avatar.Friends
                 // the friend in this sim as root agent
                 friendClient.SendTerminateFriend(exfriendID);
                 // update local cache
-                RefetchFriends(friendClient);
+                RecacheFriends(friendClient);
                 // we're done
                 return true;
             }
@@ -819,16 +843,15 @@ namespace OpenSim.Region.CoreModules.Avatar.Friends
                 if (onlineBitChanged)
                 {
                     if ((rights & (int)FriendRights.CanSeeOnline) == 1)
-                        friendClient.SendAgentOnline(new UUID[] { new UUID(userID) });
+                        friendClient.SendAgentOnline(new UUID[] { userID });
                     else
-                        friendClient.SendAgentOffline(new UUID[] { new UUID(userID) });
+                        friendClient.SendAgentOffline(new UUID[] { userID });
                 }
                 else
                 {
                     bool canEditObjectsChanged = ((rights ^ userFlags) & (int)FriendRights.CanModifyObjects) != 0;
                     if (canEditObjectsChanged)
                         friendClient.SendChangeUserRights(userID, friendID, rights);
-
                 }
 
                 // Update local cache
@@ -847,7 +870,7 @@ namespace OpenSim.Region.CoreModules.Avatar.Friends
             IClientAPI friendClient = LocateClientObject(friendID);
             if (friendClient != null)
             {
-                // the  friend in this sim as root agent
+                // the friend in this sim as root agent
                 if (online)
                     friendClient.SendAgentOnline(new UUID[] { userID });
                 else
@@ -902,8 +925,10 @@ namespace OpenSim.Region.CoreModules.Avatar.Friends
             return FriendsService.GetFriends(client.AgentId);
         }
 
-        private void RefetchFriends(IClientAPI client)
+        private void RecacheFriends(IClientAPI client)
         {
+            // FIXME: Ideally, we want to avoid doing this here since it sits the EventManager.OnMakeRootAgent event
+            // is on the critical path for transferring an avatar from one region to another.
             UUID agentID = client.AgentId;
             lock (m_Friends)
             {