On closing child agents, send separate asynchronous requests to each neighbour rather than sending all closes concurrently on a separate thread.

This is to reduce race conditions where neighbours may be responding erratically, thus mixing up create and close agent requests in time.
This mirrors OpenSimulator behaviour on enabling child agents where each region is contacted separately.

3 files changed, 5 insertions, 9 deletions

diff --git a/OpenSim/Region/Framework/Scenes/Scene.cs b/OpenSim/Region/Framework/Scenes/Scene.cs
index 50bea6f..8fe9b66 100644
--- a/OpenSim/Region/Framework/Scenes/Scene.cs
+++ b/OpenSim/Region/Framework/Scenes/Scene.cs
@@ -3440,8 +3440,8 @@ namespace OpenSim.Region.Framework.Scenes
                         List<ulong> regions = avatar.KnownRegionHandles;
                         regions.Remove(RegionInfo.RegionHandle);
 
-                        // We must do this asynchronously so that a logout isn't held up where there are many present but unresponsive neighbours.
-                        Util.FireAndForget(delegate { m_sceneGridService.SendCloseChildAgentConnections(agentID, regions); });
+                        // This ends up being done asynchronously so that a logout isn't held up where there are many present but unresponsive neighbours.
+                        m_sceneGridService.SendCloseChildAgentConnections(agentID, regions);
                     }
     
                     m_eventManager.TriggerClientClosed(agentID, this);
diff --git a/OpenSim/Region/Framework/Scenes/SceneCommunicationService.cs b/OpenSim/Region/Framework/Scenes/SceneCommunicationService.cs
index 305f8a4..8c84c98 100644
--- a/OpenSim/Region/Framework/Scenes/SceneCommunicationService.cs
+++ b/OpenSim/Region/Framework/Scenes/SceneCommunicationService.cs
@@ -222,9 +222,7 @@ namespace OpenSim.Region.Framework.Scenes
         public void SendCloseChildAgentConnections(UUID agentID, List<ulong> regionslst)
         {
             foreach (ulong handle in regionslst)
-            {
-                SendCloseChildAgent(agentID, handle);
-            }
+                Util.FireAndForget(delegate { SendCloseChildAgent(agentID, handle); });
         }
        
         public List<GridRegion> RequestNamedRegions(string name, int maxNumber)
diff --git a/OpenSim/Region/Framework/Scenes/ScenePresence.cs b/OpenSim/Region/Framework/Scenes/ScenePresence.cs
index 2a265db..9e9089b 100644
--- a/OpenSim/Region/Framework/Scenes/ScenePresence.cs
+++ b/OpenSim/Region/Framework/Scenes/ScenePresence.cs
@@ -3135,10 +3135,8 @@ namespace OpenSim.Region.Framework.Scenes
             if (byebyeRegions.Count > 0)
             {
                 m_log.Debug("[SCENE PRESENCE]: Closing " + byebyeRegions.Count + " child agents");
-                Util.FireAndForget(delegate 
-                { 
-                    m_scene.SceneGridService.SendCloseChildAgentConnections(ControllingClient.AgentId, byebyeRegions); 
-                });
+
+                m_scene.SceneGridService.SendCloseChildAgentConnections(ControllingClient.AgentId, byebyeRegions); 
             }
             
             foreach (ulong handle in byebyeRegions)