From d8ee0cbe1cf93ca521f52ce39aa2a15cb5784e48 Mon Sep 17 00:00:00 2001
From: Diva Canto
Date: Sat, 30 Apr 2011 09:24:15 -0700
Subject: First stab at cleaning up Caps. Compiles. Untested.
---
.../Region/ClientStack/Linden/UDP/LLUDPClient.cs | 697 +++++++++++++++++++++
1 file changed, 697 insertions(+)
create mode 100644 OpenSim/Region/ClientStack/Linden/UDP/LLUDPClient.cs
(limited to 'OpenSim/Region/ClientStack/Linden/UDP/LLUDPClient.cs')
diff --git a/OpenSim/Region/ClientStack/Linden/UDP/LLUDPClient.cs b/OpenSim/Region/ClientStack/Linden/UDP/LLUDPClient.cs
new file mode 100644
index 0000000..ca5501d
--- /dev/null
+++ b/OpenSim/Region/ClientStack/Linden/UDP/LLUDPClient.cs
@@ -0,0 +1,697 @@
+/*
+ * Copyright (c) Contributors, http://opensimulator.org/
+ * See CONTRIBUTORS.TXT for a full list of copyright holders.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ * * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * * Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ * * Neither the name of the OpenSimulator Project nor the
+ * names of its contributors may be used to endorse or promote products
+ * derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE DEVELOPERS ``AS IS'' AND ANY
+ * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+ * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE CONTRIBUTORS BE LIABLE FOR ANY
+ * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+using System;
+using System.Collections.Generic;
+using System.Net;
+using System.Threading;
+using log4net;
+using OpenSim.Framework;
+using OpenMetaverse;
+using OpenMetaverse.Packets;
+
+using TokenBucket = OpenSim.Region.ClientStack.LindenUDP.TokenBucket;
+
+namespace OpenSim.Region.ClientStack.LindenUDP
+{
+ #region Delegates
+
+ ///
+ /// Fired when updated networking stats are produced for this client
+ ///
+ /// Number of incoming packets received since this
+ /// event was last fired
+ /// Number of outgoing packets sent since this
+ /// event was last fired
+ /// Current total number of bytes in packets we
+ /// are waiting on ACKs for
+ public delegate void PacketStats(int inPackets, int outPackets, int unAckedBytes);
+ ///
+ /// Fired when the queue for one or more packet categories is empty. This
+ /// event can be hooked to put more data on the empty queues
+ ///
+ /// Categories of the packet queues that are empty
+ public delegate void QueueEmpty(ThrottleOutPacketTypeFlags categories);
+
+ #endregion Delegates
+
+ ///
+ /// Tracks state for a client UDP connection and provides client-specific methods
+ ///
+ public sealed class LLUDPClient
+ {
+ // TODO: Make this a config setting
+ /// Percentage of the task throttle category that is allocated to avatar and prim
+ /// state updates
+ const float STATE_TASK_PERCENTAGE = 0.8f;
+
+ private static readonly ILog m_log = LogManager.GetLogger(System.Reflection.MethodBase.GetCurrentMethod().DeclaringType);
+
+ /// The number of packet categories to throttle on. If a throttle category is added
+ /// or removed, this number must also change
+ const int THROTTLE_CATEGORY_COUNT = 8;
+
+ /// Fired when updated networking stats are produced for this client
+ public event PacketStats OnPacketStats;
+ /// Fired when the queue for a packet category is empty. This event can be
+ /// hooked to put more data on the empty queue
+ public event QueueEmpty OnQueueEmpty;
+
+ /// AgentID for this client
+ public readonly UUID AgentID;
+ /// The remote address of the connected client
+ public readonly IPEndPoint RemoteEndPoint;
+ /// Circuit code that this client is connected on
+ public readonly uint CircuitCode;
+ /// Sequence numbers of packets we've received (for duplicate checking)
+ public readonly IncomingPacketHistoryCollection PacketArchive = new IncomingPacketHistoryCollection(200);
+ /// Packets we have sent that need to be ACKed by the client
+ public readonly UnackedPacketCollection NeedAcks = new UnackedPacketCollection();
+ /// ACKs that are queued up, waiting to be sent to the client
+ public readonly OpenSim.Framework.LocklessQueue PendingAcks = new OpenSim.Framework.LocklessQueue();
+
+ /// Current packet sequence number
+ public int CurrentSequence;
+ /// Current ping sequence number
+ public byte CurrentPingSequence;
+ /// True when this connection is alive, otherwise false
+ public bool IsConnected = true;
+ /// True when this connection is paused, otherwise false
+ public bool IsPaused;
+ /// Environment.TickCount when the last packet was received for this client
+ public int TickLastPacketReceived;
+
+ /// Smoothed round-trip time. A smoothed average of the round-trip time for sending a
+ /// reliable packet to the client and receiving an ACK
+ public float SRTT;
+ /// Round-trip time variance. Measures the consistency of round-trip times
+ public float RTTVAR;
+ /// Retransmission timeout. Packets that have not been acknowledged in this number of
+ /// milliseconds or longer will be resent
+ /// Calculated from and using the
+ /// guidelines in RFC 2988
+ public int RTO;
+ /// Number of bytes received since the last acknowledgement was sent out. This is used
+ /// to loosely follow the TCP delayed ACK algorithm in RFC 1122 (4.2.3.2)
+ public int BytesSinceLastACK;
+ /// Number of packets received from this client
+ public int PacketsReceived;
+ /// Number of packets sent to this client
+ public int PacketsSent;
+ /// Number of packets resent to this client
+ public int PacketsResent;
+ /// Total byte count of unacked packets sent to this client
+ public int UnackedBytes;
+
+ /// Total number of received packets that we have reported to the OnPacketStats event(s)
+ private int m_packetsReceivedReported;
+ /// Total number of sent packets that we have reported to the OnPacketStats event(s)
+ private int m_packetsSentReported;
+ /// Holds the Environment.TickCount value of when the next OnQueueEmpty can be fired
+ private int m_nextOnQueueEmpty = 1;
+
+ /// Throttle bucket for this agent's connection
+ private readonly AdaptiveTokenBucket m_throttleClient;
+ public AdaptiveTokenBucket FlowThrottle
+ {
+ get { return m_throttleClient; }
+ }
+
+ /// Throttle bucket for this agent's connection
+ private readonly TokenBucket m_throttleCategory;
+ /// Throttle buckets for each packet category
+ private readonly TokenBucket[] m_throttleCategories;
+ /// Outgoing queues for throttled packets
+ private readonly OpenSim.Framework.LocklessQueue[] m_packetOutboxes = new OpenSim.Framework.LocklessQueue[THROTTLE_CATEGORY_COUNT];
+ /// A container that can hold one packet for each outbox, used to store
+ /// dequeued packets that are being held for throttling
+ private readonly OutgoingPacket[] m_nextPackets = new OutgoingPacket[THROTTLE_CATEGORY_COUNT];
+ /// A reference to the LLUDPServer that is managing this client
+ private readonly LLUDPServer m_udpServer;
+
+ /// Caches packed throttle information
+ private byte[] m_packedThrottles;
+
+ private int m_defaultRTO = 1000; // 1sec is the recommendation in the RFC
+ private int m_maxRTO = 60000;
+
+ ///
+ /// Default constructor
+ ///
+ /// Reference to the UDP server this client is connected to
+ /// Default throttling rates and maximum throttle limits
+ /// Parent HTB (hierarchical token bucket)
+ /// that the child throttles will be governed by
+ /// Circuit code for this connection
+ /// AgentID for the connected agent
+ /// Remote endpoint for this connection
+ public LLUDPClient(LLUDPServer server, ThrottleRates rates, TokenBucket parentThrottle, uint circuitCode, UUID agentID, IPEndPoint remoteEndPoint, int defaultRTO, int maxRTO)
+ {
+ AgentID = agentID;
+ RemoteEndPoint = remoteEndPoint;
+ CircuitCode = circuitCode;
+ m_udpServer = server;
+ if (defaultRTO != 0)
+ m_defaultRTO = defaultRTO;
+ if (maxRTO != 0)
+ m_maxRTO = maxRTO;
+
+ // Create a token bucket throttle for this client that has the scene token bucket as a parent
+ m_throttleClient = new AdaptiveTokenBucket(parentThrottle, rates.Total, rates.AdaptiveThrottlesEnabled);
+ // Create a token bucket throttle for the total categary with the client bucket as a throttle
+ m_throttleCategory = new TokenBucket(m_throttleClient, 0);
+ // Create an array of token buckets for this clients different throttle categories
+ m_throttleCategories = new TokenBucket[THROTTLE_CATEGORY_COUNT];
+
+ for (int i = 0; i < THROTTLE_CATEGORY_COUNT; i++)
+ {
+ ThrottleOutPacketType type = (ThrottleOutPacketType)i;
+
+ // Initialize the packet outboxes, where packets sit while they are waiting for tokens
+ m_packetOutboxes[i] = new OpenSim.Framework.LocklessQueue();
+ // Initialize the token buckets that control the throttling for each category
+ m_throttleCategories[i] = new TokenBucket(m_throttleCategory, rates.GetRate(type));
+ }
+
+ // Default the retransmission timeout to three seconds
+ RTO = m_defaultRTO;
+
+ // Initialize this to a sane value to prevent early disconnects
+ TickLastPacketReceived = Environment.TickCount & Int32.MaxValue;
+ }
+
+ ///
+ /// Shuts down this client connection
+ ///
+ public void Shutdown()
+ {
+ IsConnected = false;
+ for (int i = 0; i < THROTTLE_CATEGORY_COUNT; i++)
+ {
+ m_packetOutboxes[i].Clear();
+ m_nextPackets[i] = null;
+ }
+
+ // pull the throttle out of the scene throttle
+ m_throttleClient.Parent.UnregisterRequest(m_throttleClient);
+ OnPacketStats = null;
+ OnQueueEmpty = null;
+ }
+
+ ///
+ /// Gets information about this client connection
+ ///
+ /// Information about the client connection
+ public ClientInfo GetClientInfo()
+ {
+ // TODO: This data structure is wrong in so many ways. Locking and copying the entire lists
+ // of pending and needed ACKs for every client every time some method wants information about
+ // this connection is a recipe for poor performance
+ ClientInfo info = new ClientInfo();
+ info.pendingAcks = new Dictionary();
+ info.needAck = new Dictionary();
+
+ info.resendThrottle = (int)m_throttleCategories[(int)ThrottleOutPacketType.Resend].DripRate;
+ info.landThrottle = (int)m_throttleCategories[(int)ThrottleOutPacketType.Land].DripRate;
+ info.windThrottle = (int)m_throttleCategories[(int)ThrottleOutPacketType.Wind].DripRate;
+ info.cloudThrottle = (int)m_throttleCategories[(int)ThrottleOutPacketType.Cloud].DripRate;
+ info.taskThrottle = (int)m_throttleCategories[(int)ThrottleOutPacketType.Task].DripRate;
+ info.assetThrottle = (int)m_throttleCategories[(int)ThrottleOutPacketType.Asset].DripRate;
+ info.textureThrottle = (int)m_throttleCategories[(int)ThrottleOutPacketType.Texture].DripRate;
+ info.totalThrottle = (int)m_throttleCategory.DripRate;
+
+ return info;
+ }
+
+ ///
+ /// Modifies the UDP throttles
+ ///
+ /// New throttling values
+ public void SetClientInfo(ClientInfo info)
+ {
+ // TODO: Allowing throttles to be manually set from this function seems like a reasonable
+ // idea. On the other hand, letting external code manipulate our ACK accounting is not
+ // going to happen
+ throw new NotImplementedException();
+ }
+
+ ///
+ /// Return statistics information about client packet queues.
+ ///
+ ///
+ /// FIXME: This should really be done in a more sensible manner rather than sending back a formatted string.
+ ///
+ ///
+ public string GetStats()
+ {
+ return string.Format(
+ "{0,7} {1,7} {2,7} {3,9} {4,7} {5,7} {6,7} {7,7} {8,7} {9,8} {10,7} {11,7}",
+ PacketsReceived,
+ PacketsSent,
+ PacketsResent,
+ UnackedBytes,
+ m_packetOutboxes[(int)ThrottleOutPacketType.Resend].Count,
+ m_packetOutboxes[(int)ThrottleOutPacketType.Land].Count,
+ m_packetOutboxes[(int)ThrottleOutPacketType.Wind].Count,
+ m_packetOutboxes[(int)ThrottleOutPacketType.Cloud].Count,
+ m_packetOutboxes[(int)ThrottleOutPacketType.Task].Count,
+ m_packetOutboxes[(int)ThrottleOutPacketType.Texture].Count,
+ m_packetOutboxes[(int)ThrottleOutPacketType.Asset].Count,
+ m_packetOutboxes[(int)ThrottleOutPacketType.State].Count);
+ }
+
+ public void SendPacketStats()
+ {
+ PacketStats callback = OnPacketStats;
+ if (callback != null)
+ {
+ int newPacketsReceived = PacketsReceived - m_packetsReceivedReported;
+ int newPacketsSent = PacketsSent - m_packetsSentReported;
+
+ callback(newPacketsReceived, newPacketsSent, UnackedBytes);
+
+ m_packetsReceivedReported += newPacketsReceived;
+ m_packetsSentReported += newPacketsSent;
+ }
+ }
+
+ public void SetThrottles(byte[] throttleData)
+ {
+ byte[] adjData;
+ int pos = 0;
+
+ if (!BitConverter.IsLittleEndian)
+ {
+ byte[] newData = new byte[7 * 4];
+ Buffer.BlockCopy(throttleData, 0, newData, 0, 7 * 4);
+
+ for (int i = 0; i < 7; i++)
+ Array.Reverse(newData, i * 4, 4);
+
+ adjData = newData;
+ }
+ else
+ {
+ adjData = throttleData;
+ }
+
+ // 0.125f converts from bits to bytes
+ int resend = (int)(BitConverter.ToSingle(adjData, pos) * 0.125f); pos += 4;
+ int land = (int)(BitConverter.ToSingle(adjData, pos) * 0.125f); pos += 4;
+ int wind = (int)(BitConverter.ToSingle(adjData, pos) * 0.125f); pos += 4;
+ int cloud = (int)(BitConverter.ToSingle(adjData, pos) * 0.125f); pos += 4;
+ int task = (int)(BitConverter.ToSingle(adjData, pos) * 0.125f); pos += 4;
+ int texture = (int)(BitConverter.ToSingle(adjData, pos) * 0.125f); pos += 4;
+ int asset = (int)(BitConverter.ToSingle(adjData, pos) * 0.125f);
+ // State is a subcategory of task that we allocate a percentage to
+ int state = 0;
+
+ // Make sure none of the throttles are set below our packet MTU,
+ // otherwise a throttle could become permanently clogged
+ resend = Math.Max(resend, LLUDPServer.MTU);
+ land = Math.Max(land, LLUDPServer.MTU);
+ wind = Math.Max(wind, LLUDPServer.MTU);
+ cloud = Math.Max(cloud, LLUDPServer.MTU);
+ task = Math.Max(task, LLUDPServer.MTU);
+ texture = Math.Max(texture, LLUDPServer.MTU);
+ asset = Math.Max(asset, LLUDPServer.MTU);
+
+ //int total = resend + land + wind + cloud + task + texture + asset;
+ //m_log.DebugFormat("[LLUDPCLIENT]: {0} is setting throttles. Resend={1}, Land={2}, Wind={3}, Cloud={4}, Task={5}, Texture={6}, Asset={7}, Total={8}",
+ // AgentID, resend, land, wind, cloud, task, texture, asset, total);
+
+ // Update the token buckets with new throttle values
+ TokenBucket bucket;
+
+ bucket = m_throttleCategories[(int)ThrottleOutPacketType.Resend];
+ bucket.RequestedDripRate = resend;
+
+ bucket = m_throttleCategories[(int)ThrottleOutPacketType.Land];
+ bucket.RequestedDripRate = land;
+
+ bucket = m_throttleCategories[(int)ThrottleOutPacketType.Wind];
+ bucket.RequestedDripRate = wind;
+
+ bucket = m_throttleCategories[(int)ThrottleOutPacketType.Cloud];
+ bucket.RequestedDripRate = cloud;
+
+ bucket = m_throttleCategories[(int)ThrottleOutPacketType.Asset];
+ bucket.RequestedDripRate = asset;
+
+ bucket = m_throttleCategories[(int)ThrottleOutPacketType.Task];
+ bucket.RequestedDripRate = task;
+
+ bucket = m_throttleCategories[(int)ThrottleOutPacketType.State];
+ bucket.RequestedDripRate = state;
+
+ bucket = m_throttleCategories[(int)ThrottleOutPacketType.Texture];
+ bucket.RequestedDripRate = texture;
+
+ // Reset the packed throttles cached data
+ m_packedThrottles = null;
+ }
+
+ public byte[] GetThrottlesPacked(float multiplier)
+ {
+ byte[] data = m_packedThrottles;
+
+ if (data == null)
+ {
+ float rate;
+
+ data = new byte[7 * 4];
+ int i = 0;
+
+ // multiply by 8 to convert bytes back to bits
+ rate = (float)m_throttleCategories[(int)ThrottleOutPacketType.Resend].RequestedDripRate * 8 * multiplier;
+ Buffer.BlockCopy(Utils.FloatToBytes(rate), 0, data, i, 4); i += 4;
+
+ rate = (float)m_throttleCategories[(int)ThrottleOutPacketType.Land].RequestedDripRate * 8 * multiplier;
+ Buffer.BlockCopy(Utils.FloatToBytes(rate), 0, data, i, 4); i += 4;
+
+ rate = (float)m_throttleCategories[(int)ThrottleOutPacketType.Wind].RequestedDripRate * 8 * multiplier;
+ Buffer.BlockCopy(Utils.FloatToBytes(rate), 0, data, i, 4); i += 4;
+
+ rate = (float)m_throttleCategories[(int)ThrottleOutPacketType.Cloud].RequestedDripRate * 8 * multiplier;
+ Buffer.BlockCopy(Utils.FloatToBytes(rate), 0, data, i, 4); i += 4;
+
+ rate = (float)m_throttleCategories[(int)ThrottleOutPacketType.Task].RequestedDripRate * 8 * multiplier;
+ Buffer.BlockCopy(Utils.FloatToBytes(rate), 0, data, i, 4); i += 4;
+
+ rate = (float)m_throttleCategories[(int)ThrottleOutPacketType.Texture].RequestedDripRate * 8 * multiplier;
+ Buffer.BlockCopy(Utils.FloatToBytes(rate), 0, data, i, 4); i += 4;
+
+ rate = (float)m_throttleCategories[(int)ThrottleOutPacketType.Asset].RequestedDripRate * 8 * multiplier;
+ Buffer.BlockCopy(Utils.FloatToBytes(rate), 0, data, i, 4); i += 4;
+
+ m_packedThrottles = data;
+ }
+
+ return data;
+ }
+
+ ///
+ /// Queue an outgoing packet if appropriate.
+ ///
+ ///
+ /// Always queue the packet if at all possible.
+ ///
+ /// true if the packet has been queued,
+ /// false if the packet has not been queued and should be sent immediately.
+ ///
+ public bool EnqueueOutgoing(OutgoingPacket packet, bool forceQueue)
+ {
+ int category = (int)packet.Category;
+
+ if (category >= 0 && category < m_packetOutboxes.Length)
+ {
+ OpenSim.Framework.LocklessQueue queue = m_packetOutboxes[category];
+ TokenBucket bucket = m_throttleCategories[category];
+
+ // Don't send this packet if there is already a packet waiting in the queue
+ // even if we have the tokens to send it, tokens should go to the already
+ // queued packets
+ if (queue.Count > 0)
+ {
+ queue.Enqueue(packet);
+ return true;
+ }
+
+
+ if (!forceQueue && bucket.RemoveTokens(packet.Buffer.DataLength))
+ {
+ // Enough tokens were removed from the bucket, the packet will not be queued
+ return false;
+ }
+ else
+ {
+ // Force queue specified or not enough tokens in the bucket, queue this packet
+ queue.Enqueue(packet);
+ return true;
+ }
+ }
+ else
+ {
+ // We don't have a token bucket for this category, so it will not be queued
+ return false;
+ }
+ }
+
+ ///
+ /// Loops through all of the packet queues for this client and tries to send
+ /// an outgoing packet from each, obeying the throttling bucket limits
+ ///
+ ///
+ ///
+ /// Packet queues are inspected in ascending numerical order starting from 0. Therefore, queues with a lower
+ /// ThrottleOutPacketType number will see their packet get sent first (e.g. if both Land and Wind queues have
+ /// packets, then the packet at the front of the Land queue will be sent before the packet at the front of the
+ /// wind queue).
+ ///
+ /// This function is only called from a synchronous loop in the
+ /// UDPServer so we don't need to bother making this thread safe
+ ///
+ ///
+ /// True if any packets were sent, otherwise false
+ public bool DequeueOutgoing()
+ {
+ OutgoingPacket packet;
+ OpenSim.Framework.LocklessQueue queue;
+ TokenBucket bucket;
+ bool packetSent = false;
+ ThrottleOutPacketTypeFlags emptyCategories = 0;
+
+ //string queueDebugOutput = String.Empty; // Serious debug business
+
+ for (int i = 0; i < THROTTLE_CATEGORY_COUNT; i++)
+ {
+ bucket = m_throttleCategories[i];
+ //queueDebugOutput += m_packetOutboxes[i].Count + " "; // Serious debug business
+
+ if (m_nextPackets[i] != null)
+ {
+ // This bucket was empty the last time we tried to send a packet,
+ // leaving a dequeued packet still waiting to be sent out. Try to
+ // send it again
+ OutgoingPacket nextPacket = m_nextPackets[i];
+ if (bucket.RemoveTokens(nextPacket.Buffer.DataLength))
+ {
+ // Send the packet
+ m_udpServer.SendPacketFinal(nextPacket);
+ m_nextPackets[i] = null;
+ packetSent = true;
+ }
+ }
+ else
+ {
+ // No dequeued packet waiting to be sent, try to pull one off
+ // this queue
+ queue = m_packetOutboxes[i];
+ if (queue.Dequeue(out packet))
+ {
+ // A packet was pulled off the queue. See if we have
+ // enough tokens in the bucket to send it out
+ if (bucket.RemoveTokens(packet.Buffer.DataLength))
+ {
+ // Send the packet
+ m_udpServer.SendPacketFinal(packet);
+ packetSent = true;
+ }
+ else
+ {
+ // Save the dequeued packet for the next iteration
+ m_nextPackets[i] = packet;
+ }
+
+ // If the queue is empty after this dequeue, fire the queue
+ // empty callback now so it has a chance to fill before we
+ // get back here
+ if (queue.Count == 0)
+ emptyCategories |= CategoryToFlag(i);
+ }
+ else
+ {
+ // No packets in this queue. Fire the queue empty callback
+ // if it has not been called recently
+ emptyCategories |= CategoryToFlag(i);
+ }
+ }
+ }
+
+ if (emptyCategories != 0)
+ BeginFireQueueEmpty(emptyCategories);
+
+ //m_log.Info("[LLUDPCLIENT]: Queues: " + queueDebugOutput); // Serious debug business
+ return packetSent;
+ }
+
+ ///
+ /// Called when an ACK packet is received and a round-trip time for a
+ /// packet is calculated. This is used to calculate the smoothed
+ /// round-trip time, round trip time variance, and finally the
+ /// retransmission timeout
+ ///
+ /// Round-trip time of a single packet and its
+ /// acknowledgement
+ public void UpdateRoundTrip(float r)
+ {
+ const float ALPHA = 0.125f;
+ const float BETA = 0.25f;
+ const float K = 4.0f;
+
+ if (RTTVAR == 0.0f)
+ {
+ // First RTT measurement
+ SRTT = r;
+ RTTVAR = r * 0.5f;
+ }
+ else
+ {
+ // Subsequence RTT measurement
+ RTTVAR = (1.0f - BETA) * RTTVAR + BETA * Math.Abs(SRTT - r);
+ SRTT = (1.0f - ALPHA) * SRTT + ALPHA * r;
+ }
+
+ int rto = (int)(SRTT + Math.Max(m_udpServer.TickCountResolution, K * RTTVAR));
+
+ // Clamp the retransmission timeout to manageable values
+ rto = Utils.Clamp(rto, m_defaultRTO, m_maxRTO);
+
+ RTO = rto;
+
+ //m_log.Debug("[LLUDPCLIENT]: Setting agent " + this.Agent.FullName + "'s RTO to " + RTO + "ms with an RTTVAR of " +
+ // RTTVAR + " based on new RTT of " + r + "ms");
+ }
+
+ ///
+ /// Exponential backoff of the retransmission timeout, per section 5.5
+ /// of RFC 2988
+ ///
+ public void BackoffRTO()
+ {
+ // Reset SRTT and RTTVAR, we assume they are bogus since things
+ // didn't work out and we're backing off the timeout
+ SRTT = 0.0f;
+ RTTVAR = 0.0f;
+
+ // Double the retransmission timeout
+ RTO = Math.Min(RTO * 2, m_maxRTO);
+ }
+
+ ///
+ /// Does an early check to see if this queue empty callback is already
+ /// running, then asynchronously firing the event
+ ///
+ /// Throttle category to fire the callback
+ /// for
+ private void BeginFireQueueEmpty(ThrottleOutPacketTypeFlags categories)
+ {
+ if (m_nextOnQueueEmpty != 0 && (Environment.TickCount & Int32.MaxValue) >= m_nextOnQueueEmpty)
+ {
+ // Use a value of 0 to signal that FireQueueEmpty is running
+ m_nextOnQueueEmpty = 0;
+ // Asynchronously run the callback
+ Util.FireAndForget(FireQueueEmpty, categories);
+ }
+ }
+
+ ///
+ /// Fires the OnQueueEmpty callback and sets the minimum time that it
+ /// can be called again
+ ///
+ /// Throttle categories to fire the callback for,
+ /// stored as an object to match the WaitCallback delegate
+ /// signature
+ private void FireQueueEmpty(object o)
+ {
+ const int MIN_CALLBACK_MS = 30;
+
+ ThrottleOutPacketTypeFlags categories = (ThrottleOutPacketTypeFlags)o;
+ QueueEmpty callback = OnQueueEmpty;
+
+ int start = Environment.TickCount & Int32.MaxValue;
+
+ if (callback != null)
+ {
+ try { callback(categories); }
+ catch (Exception e) { m_log.Error("[LLUDPCLIENT]: OnQueueEmpty(" + categories + ") threw an exception: " + e.Message, e); }
+ }
+
+ m_nextOnQueueEmpty = start + MIN_CALLBACK_MS;
+ if (m_nextOnQueueEmpty == 0)
+ m_nextOnQueueEmpty = 1;
+ }
+
+ ///
+ /// Converts a integer to a
+ /// flag value
+ ///
+ /// Throttle category to convert
+ /// Flag representation of the throttle category
+ private static ThrottleOutPacketTypeFlags CategoryToFlag(int i)
+ {
+ ThrottleOutPacketType category = (ThrottleOutPacketType)i;
+
+ /*
+ * Land = 1,
+ /// Wind data
+ Wind = 2,
+ /// Cloud data
+ Cloud = 3,
+ /// Any packets that do not fit into the other throttles
+ Task = 4,
+ /// Texture assets
+ Texture = 5,
+ /// Non-texture assets
+ Asset = 6,
+ /// Avatar and primitive data
+ /// This is a sub-category of Task
+ State = 7,
+ */
+
+ switch (category)
+ {
+ case ThrottleOutPacketType.Land:
+ return ThrottleOutPacketTypeFlags.Land;
+ case ThrottleOutPacketType.Wind:
+ return ThrottleOutPacketTypeFlags.Wind;
+ case ThrottleOutPacketType.Cloud:
+ return ThrottleOutPacketTypeFlags.Cloud;
+ case ThrottleOutPacketType.Task:
+ return ThrottleOutPacketTypeFlags.Task;
+ case ThrottleOutPacketType.Texture:
+ return ThrottleOutPacketTypeFlags.Texture;
+ case ThrottleOutPacketType.Asset:
+ return ThrottleOutPacketTypeFlags.Asset;
+ case ThrottleOutPacketType.State:
+ return ThrottleOutPacketTypeFlags.State;
+ default:
+ return 0;
+ }
+ }
+ }
+}
--
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