Improvements to the ServiceThrottleModule: added a category and an itemid to the interface, so that duplicate requests aren't enqueued more than once.

OpenSim/Region/CoreModules/Framework/ServiceThrottle/ServiceThrottleModule.cs

@@ -50,17 +50,15 @@ namespace OpenSim.Region.CoreModules.Framework
         private readonly List<Scene> m_scenes = new List<Scene>();
         private System.Timers.Timer m_timer = new System.Timers.Timer();
 
-        //private OpenSim.Framework.BlockingQueue<GridRegionRequest> m_RequestQueue = new OpenSim.Framework.BlockingQueue<GridRegionRequest>();
-        // private OpenSim.Framework.DoubleQueue<GridRegionRequest> m_RequestQueue = new OpenSim.Framework.DoubleQueue<GridRegionRequest>();
-        //private Queue<GridRegionRequest> m_RequestQueue = new Queue<GridRegionRequest>();
         private Queue<Action> m_RequestQueue = new Queue<Action>();
+        private Dictionary<string, List<string>> m_Pending = new Dictionary<string, List<string>>();
         private int m_Interval;
 
         #region ISharedRegionModule
 
         public void Initialise(IConfigSource config)
         {
-            m_Interval = Util.GetConfigVarFromSections<int>(config, "Interval", new string[] { "ServiceThrottle" }, 2000);
+            m_Interval = Util.GetConfigVarFromSections<int>(config, "Interval", new string[] { "ServiceThrottle" }, 5000);
 
             m_timer = new System.Timers.Timer();
             m_timer.AutoReset = false;
@@ -159,18 +157,37 @@ namespace OpenSim.Region.CoreModules.Framework
                     client.SendRegionHandle(regionID, r.RegionHandle);
             };
 
-            lock (m_RequestQueue)
-                m_RequestQueue.Enqueue(action);
-
+            Enqueue("region", regionID.ToString(), action);
         }
 
         #endregion Events
 
         #region IServiceThrottleModule
 
-        public void Enqueue(Action continuation)
+        public void Enqueue(string category, string itemid, Action continuation)
         {
-            m_RequestQueue.Enqueue(continuation);
+            lock (m_RequestQueue)
+            {
+                if (m_Pending.ContainsKey(category))
+                {
+                    if (m_Pending[category].Contains(itemid))
+                        // Don't enqueue, it's already pending
+                        return;
+                }
+                else
+                    m_Pending.Add(category, new List<string>());
+
+                m_Pending[category].Add(itemid);
+
+                m_RequestQueue.Enqueue(delegate
+                {
+                    continuation();
+                    lock (m_RequestQueue)
+                    {
+                        m_Pending[category].Remove(itemid);
+                    }
+                });
+            }
         }
 
         #endregion IServiceThrottleModule

OpenSim/Region/CoreModules/Framework/UserManagement/UserManagementModule.cs

@@ -173,7 +173,7 @@ namespace OpenSim.Region.CoreModules.Framework.UserManagement
                 }
 
                 // Not found in cache, queue continuation
-                m_ServiceThrottle.Enqueue(delegate
+                m_ServiceThrottle.Enqueue("name", uuid.ToString(),  delegate
                 {
                     //m_log.DebugFormat("[YYY]: Name request {0}", uuid);
                     bool foundRealName = TryGetUserNames(uuid, names);

OpenSim/Region/Framework/Interfaces/IServiceThrottleModule.cs

@@ -5,7 +5,15 @@ namespace OpenSim.Region.Framework.Interfaces
 {
     public interface IServiceThrottleModule
     {
-        void Enqueue(Action continuation);
+        /// <summary>
+        /// Enqueue a continuation meant to get a resource from elsewhere.
+        /// As usual with CPS, caller beware: if that continuation is a never-ending computation,
+        /// the whole thread will be blocked, and no requests are processed
+        /// </summary>
+        /// <param name="category">Category of the resource (e.g. name, region)</param>
+        /// <param name="itemid">The resource identifier</param>
+        /// <param name="continuation">The continuation to be executed</param>
+        void Enqueue(string category, string itemid, Action continuation);
     }
 
 }

bin/OpenSimDefaults.ini

@@ -1727,5 +1727,9 @@ MaxStringSpace = 0
 	;; {MaxDistance} {} {Cut-off distance at which sounds will not be sent to users} {100.0}
 	MaxDistance = 100.0
 
+[ServiceThrottle]
+    ;; Default time interval (in ms) for the throttle service thread to wake up
+    Interval = 5000
+
 [Modules]
     Include-modules = "addon-modules/*/config/*.ini"