4 files changed, 53 insertions, 19 deletions

diff --git a/OpenSim/Region/ClientStack/Linden/UDP/LLUDPClient.cs b/OpenSim/Region/ClientStack/Linden/UDP/LLUDPClient.cs
index 8f14806..de91856 100644
--- a/OpenSim/Region/ClientStack/Linden/UDP/LLUDPClient.cs
+++ b/OpenSim/Region/ClientStack/Linden/UDP/LLUDPClient.cs
@@ -229,7 +229,7 @@ namespace OpenSim.Region.ClientStack.LindenUDP
             m_throttleClient 
                 = new AdaptiveTokenBucket(
                     string.Format("adaptive throttle for {0} in {1}", AgentID, server.Scene.Name), 
-                    parentThrottle, 0, rates.Total, rates.AdaptiveThrottlesEnabled);
+                    parentThrottle, 0, rates.Total, rates.MinimumAdaptiveThrottleRate, rates.AdaptiveThrottlesEnabled);
 
             // Create an array of token buckets for this clients different throttle categories
             m_throttleCategories = new TokenBucket[THROTTLE_CATEGORY_COUNT];
diff --git a/OpenSim/Region/ClientStack/Linden/UDP/ThrottleRates.cs b/OpenSim/Region/ClientStack/Linden/UDP/ThrottleRates.cs
index dd15cc7..7a2756b 100644
--- a/OpenSim/Region/ClientStack/Linden/UDP/ThrottleRates.cs
+++ b/OpenSim/Region/ClientStack/Linden/UDP/ThrottleRates.cs
@@ -58,7 +58,14 @@ namespace OpenSim.Region.ClientStack.LindenUDP
 
         /// <summary>Flag used to enable adaptive throttles</summary>
         public bool AdaptiveThrottlesEnabled;
-        
+ 
+        /// <summary>
+        /// Set the minimum rate that the adaptive throttles can set. The viewer
+        /// can still throttle lower than this, but the adaptive throttles will
+        /// never decrease rates below this no matter how many packets are dropped
+        /// </summary>
+        public Int64 MinimumAdaptiveThrottleRate;
+ 
         /// <summary>Amount of the texture throttle to steal for the task throttle</summary>
         public double CannibalizeTextureRate;
 
@@ -84,7 +91,8 @@ namespace OpenSim.Region.ClientStack.LindenUDP
                 Total = throttleConfig.GetInt("client_throttle_max_bps", 0);
 
                 AdaptiveThrottlesEnabled = throttleConfig.GetBoolean("enable_adaptive_throttles", false);
-                
+                MinimumAdaptiveThrottleRate = throttleConfig.GetInt("adaptive_throttle_min_bps", 32000);
+
                 CannibalizeTextureRate = (double)throttleConfig.GetFloat("CannibalizeTextureRate", 0.0f);
                 CannibalizeTextureRate = Util.Clamp<double>(CannibalizeTextureRate,0.0, 0.9);
             }
diff --git a/OpenSim/Region/ClientStack/Linden/UDP/TokenBucket.cs b/OpenSim/Region/ClientStack/Linden/UDP/TokenBucket.cs
index d215595..c0cdff6 100644
--- a/OpenSim/Region/ClientStack/Linden/UDP/TokenBucket.cs
+++ b/OpenSim/Region/ClientStack/Linden/UDP/TokenBucket.cs
@@ -392,13 +392,29 @@ namespace OpenSim.Region.ClientStack.LindenUDP
         }
                 
         /// <summary>
-        /// The minimum rate for flow control. Minimum drip rate is one
-        /// packet per second. Open the throttle to 15 packets per second
-        /// or about 160kbps.
+        /// The minimum rate for adaptive flow control. 
         /// </summary>
-        protected const Int64 m_minimumFlow = m_minimumDripRate * 15;
+        protected Int64 m_minimumFlow = 32000;
+        public Int64 MinimumFlow
+        {
+            get { return m_minimumFlow; }
+            set
+            {
+                m_minimumFlow = value;
+                TargetDripRate = Math.Max(m_minimumFlow, TargetDripRate);
+                AdjustedDripRate = Math.Max(m_minimumFlow, AdjustedDripRate);
+            }
+        }
 
-        public AdaptiveTokenBucket(string identifier, TokenBucket parent, Int64 requestedDripRate, Int64 maxDripRate, bool enabled) 
+        /// <summary>
+        /// Constructor for the AdaptiveTokenBucket class
+        /// <param name="identifier">Unique identifier for the client</param>
+        /// <param name="parent">Parent bucket in the hierarchy</param>
+        /// <param name="requestedDripRate"></param>
+        /// <param name="maxDripRate">The ceiling rate for adaptation</param>
+        /// <param name="minDripRate">The floor rate for adaptation</param>
+        /// </summary>
+        public AdaptiveTokenBucket(string identifier, TokenBucket parent, Int64 requestedDripRate, Int64 maxDripRate, Int64 minDripRate, bool enabled) 
             : base(identifier, parent, requestedDripRate, maxDripRate)
         {
             AdaptiveEnabled = enabled;
@@ -406,34 +422,37 @@ namespace OpenSim.Region.ClientStack.LindenUDP
             if (AdaptiveEnabled)
             {
 //                m_log.DebugFormat("[TOKENBUCKET]: Adaptive throttle enabled");
+                m_minimumFlow = minDripRate;
                 TargetDripRate = m_minimumFlow;
                 AdjustedDripRate = m_minimumFlow;
             }
         }
                 
-        // <summary>
-        // Reliable packets sent to the client for which we never received an ack adjust the drip rate down.
-        // </summary>
-        public void ExpirePackets(Int32 count)
+        /// <summary>
+        /// Reliable packets sent to the client for which we never received an ack adjust the drip rate down.
+        /// <param name="packets">Number of packets that expired without successful delivery</param>
+        /// </summary>
+        public void ExpirePackets(Int32 packets)
         {
             if (AdaptiveEnabled)
             {
                 if (DebugLevel > 0)
                     m_log.WarnFormat(
                         "[ADAPTIVEBUCKET] drop {0} by {1} expired packets for {2}", 
-                        AdjustedDripRate, count, Identifier);
+                        AdjustedDripRate, packets, Identifier);
 
-                AdjustedDripRate = (Int64) (AdjustedDripRate / Math.Pow(2,count));
+                AdjustedDripRate = (Int64) (AdjustedDripRate / Math.Pow(2,packets));
             }
         }
 
-        // <summary>
-        // Reliable packets acked by the client adjust the drip rate up.
-        // </summary>
-        public void AcknowledgePackets(Int32 count)
+        /// <summary>
+        /// Reliable packets acked by the client adjust the drip rate up.
+        /// <param name="bytes">Number of bytes acknowledged</param>
+        /// </summary>
+        public void AcknowledgePackets(Int32 bytes)
         {
             if (AdaptiveEnabled)
-                AdjustedDripRate = AdjustedDripRate + count;
+                AdjustedDripRate = AdjustedDripRate + bytes;
         }
     }
 }
\ No newline at end of file
diff --git a/bin/OpenSimDefaults.ini b/bin/OpenSimDefaults.ini
index 3e9514e..212baab 100644
--- a/bin/OpenSimDefaults.ini
+++ b/bin/OpenSimDefaults.ini
@@ -544,6 +544,13 @@
     ;
     ;client_throttle_max_bps = 187500
 
+    ; Minimum bytes per second to send to any single client as a result of
+    ; adaptive throttling. Viewer preferences set to a lower number will 
+    ; override the settin. The example given here ensures that adaptive
+    ; throttling will never decrease per client bandwidth below 256 kbps.
+    ;
+    ;adaptive_throttle_min_bps = 32000
+
     ; Adaptive throttling attempts to limit network overload when multiple
     ; clients login by starting each connection more slowly. Disabled by
     ; default