Changed locks to prevent deadlocks (especially during multi-region Load OAR)

3 files changed, 61 insertions, 39 deletions

diff --git a/OpenSim/Region/CoreModules/World/Archiver/ArchiveReadRequest.cs b/OpenSim/Region/CoreModules/World/Archiver/ArchiveReadRequest.cs
index c810242..32d245f 100644
--- a/OpenSim/Region/CoreModules/World/Archiver/ArchiveReadRequest.cs
+++ b/OpenSim/Region/CoreModules/World/Archiver/ArchiveReadRequest.cs
@@ -604,13 +604,18 @@ namespace OpenSim.Region.CoreModules.World.Archiver
         /// <returns></returns>
         private bool ResolveUserUuid(Scene scene, UUID uuid)
         {
-            if (!m_validUserUuids.ContainsKey(uuid))
+            lock (m_validUserUuids)
             {
-                UserAccount account = scene.UserAccountService.GetUserAccount(scene.RegionInfo.ScopeID, uuid);
-                m_validUserUuids.Add(uuid, account != null);
-            }
+                if (!m_validUserUuids.ContainsKey(uuid))
+                {
+                    // Note: we call GetUserAccount() inside the lock because this UserID is likely
+                    // to occur many times, and we only want to query the users service once.
+                    UserAccount account = scene.UserAccountService.GetUserAccount(scene.RegionInfo.ScopeID, uuid);
+                    m_validUserUuids.Add(uuid, account != null);
+                }
 
-            return m_validUserUuids[uuid];
+                return m_validUserUuids[uuid];
+            }
         }
 
         /// <summary>
@@ -623,19 +628,26 @@ namespace OpenSim.Region.CoreModules.World.Archiver
             if (uuid == UUID.Zero)
                 return true;    // this means the object has no group
 
-            if (!m_validGroupUuids.ContainsKey(uuid))
+            lock (m_validGroupUuids)
             {
-                bool exists;
-                
-                if (m_groupsModule == null)
-                    exists = false;
-                else
-                    exists = (m_groupsModule.GetGroupRecord(uuid) != null);
+                if (!m_validGroupUuids.ContainsKey(uuid))
+                {
+                    bool exists;
+                    if (m_groupsModule == null)
+                    {
+                        exists = false;
+                    }
+                    else
+                    {
+                        // Note: we call GetGroupRecord() inside the lock because this GroupID is likely
+                        // to occur many times, and we only want to query the groups service once.
+                        exists = (m_groupsModule.GetGroupRecord(uuid) != null);
+                    }
+                    m_validGroupUuids.Add(uuid, exists);
+                }
 
-                m_validGroupUuids.Add(uuid, exists);
+                return m_validGroupUuids[uuid];
             }
-
-            return m_validGroupUuids[uuid];
         }
 
         /// Load an asset
diff --git a/OpenSim/Region/CoreModules/World/Land/LandManagementModule.cs b/OpenSim/Region/CoreModules/World/Land/LandManagementModule.cs
index e85b7a2..4b1e6b9 100644
--- a/OpenSim/Region/CoreModules/World/Land/LandManagementModule.cs
+++ b/OpenSim/Region/CoreModules/World/Land/LandManagementModule.cs
@@ -287,14 +287,15 @@ namespace OpenSim.Region.CoreModules.World.Land
             LandData newData = data.Copy();
             newData.LocalID = local_id;
 
+            ILandObject land;
             lock (m_landList)
             {
-                if (m_landList.ContainsKey(local_id))
-                {
-                    m_landList[local_id].LandData = newData;
-                    m_scene.EventManager.TriggerLandObjectUpdated((uint)local_id, m_landList[local_id]);
-                }
+                if (m_landList.TryGetValue(local_id, out land))
+                    land.LandData = newData;
             }
+
+            if (land != null)
+                m_scene.EventManager.TriggerLandObjectUpdated((uint)local_id, land);
         }
 
         public bool AllowedForcefulBans
@@ -613,7 +614,7 @@ namespace OpenSim.Region.CoreModules.World.Land
             // Only now can we add the prim counts to the land object - we rely on the global ID which is generated
             // as a random UUID inside LandData initialization
             if (m_primCountModule != null)
-                new_land.PrimCounts = m_primCountModule.GetPrimCounts(new_land.LandData.GlobalID);            
+                new_land.PrimCounts = m_primCountModule.GetPrimCounts(new_land.LandData.GlobalID);
 
             lock (m_landList)
             {
@@ -650,6 +651,7 @@ namespace OpenSim.Region.CoreModules.World.Land
         /// <param name="local_id">Land.localID of the peice of land to remove.</param>
         public void removeLandObject(int local_id)
         {
+            ILandObject land;
             lock (m_landList)
             {
                 for (int x = 0; x < 64; x++)
@@ -666,9 +668,11 @@ namespace OpenSim.Region.CoreModules.World.Land
                     }
                 }
 
-                m_scene.EventManager.TriggerLandObjectRemoved(m_landList[local_id].LandData.GlobalID);
+                land = m_landList[local_id];
                 m_landList.Remove(local_id);
             }
+
+            m_scene.EventManager.TriggerLandObjectRemoved(land.LandData.GlobalID);
         }
         
         /// <summary>
@@ -676,21 +680,27 @@ namespace OpenSim.Region.CoreModules.World.Land
         /// </summary>        
         public void Clear(bool setupDefaultParcel)
         {
+            List<ILandObject> parcels;
             lock (m_landList)
             {
-                foreach (ILandObject lo in m_landList.Values)
-                {
-                    //m_scene.SimulationDataService.RemoveLandObject(lo.LandData.GlobalID);
-                    m_scene.EventManager.TriggerLandObjectRemoved(lo.LandData.GlobalID);
-                }
+                parcels = new List<ILandObject>(m_landList.Values);
+            }
+
+            foreach (ILandObject lo in parcels)
+            {
+                //m_scene.SimulationDataService.RemoveLandObject(lo.LandData.GlobalID);
+                m_scene.EventManager.TriggerLandObjectRemoved(lo.LandData.GlobalID);
+            }
 
+            lock (m_landList)
+            {
                 m_landList.Clear();
 
                 ResetSimLandObjects();
-
-                if (setupDefaultParcel)
-                    CreateDefaultParcel();
             }
+            
+            if (setupDefaultParcel)
+                CreateDefaultParcel();
         }
 
         private void performFinalLandJoin(ILandObject master, ILandObject slave)
@@ -1458,11 +1468,8 @@ namespace OpenSim.Region.CoreModules.World.Land
 
         public void EventManagerOnNoLandDataFromStorage()
         {
-            lock (m_landList)
-            {
-                ResetSimLandObjects();
-                CreateDefaultParcel();
-            }
+            ResetSimLandObjects();
+            CreateDefaultParcel();
         }
 
         #endregion
diff --git a/OpenSim/Region/CoreModules/World/Land/PrimCountModule.cs b/OpenSim/Region/CoreModules/World/Land/PrimCountModule.cs
index f9cc0cf..9b51cc8 100644
--- a/OpenSim/Region/CoreModules/World/Land/PrimCountModule.cs
+++ b/OpenSim/Region/CoreModules/World/Land/PrimCountModule.cs
@@ -490,11 +490,14 @@ namespace OpenSim.Region.CoreModules.World.Land
 
             m_Scene.ForEachSOG(AddObject);
 
-            List<UUID> primcountKeys = new List<UUID>(m_PrimCounts.Keys);
-            foreach (UUID k in primcountKeys)
+            lock (m_PrimCounts)
             {
-                if (!m_OwnerMap.ContainsKey(k))
-                    m_PrimCounts.Remove(k);
+                List<UUID> primcountKeys = new List<UUID>(m_PrimCounts.Keys);
+                foreach (UUID k in primcountKeys)
+                {
+                    if (!m_OwnerMap.ContainsKey(k))
+                        m_PrimCounts.Remove(k);
+                }
             }
             
             m_Tainted = false;