676 lines
31 KiB
C#
676 lines
31 KiB
C#
/*
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* Copyright (c) Contributors, http://opensimulator.org/
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* See CONTRIBUTORS.TXT for a full list of copyright holders.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions are met:
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* * Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* * Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* * Neither the name of the OpenSimulator Project nor the
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* names of its contributors may be used to endorse or promote products
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* derived from this software without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE DEVELOPERS ``AS IS'' AND ANY
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* EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
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* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
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* DISCLAIMED. IN NO EVENT SHALL THE CONTRIBUTORS BE LIABLE FOR ANY
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* DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
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* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
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* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
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* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
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* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*/
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using System;
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using System.Collections.Generic;
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using System.Net;
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using System.Threading;
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using log4net;
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using OpenSim.Framework;
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using OpenMetaverse;
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using OpenMetaverse.Packets;
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using TokenBucket = OpenSim.Region.ClientStack.LindenUDP.TokenBucket;
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namespace OpenSim.Region.ClientStack.LindenUDP
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{
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#region Delegates
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/// <summary>
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/// Fired when updated networking stats are produced for this client
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/// </summary>
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/// <param name="inPackets">Number of incoming packets received since this
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/// event was last fired</param>
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/// <param name="outPackets">Number of outgoing packets sent since this
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/// event was last fired</param>
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/// <param name="unAckedBytes">Current total number of bytes in packets we
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/// are waiting on ACKs for</param>
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public delegate void PacketStats(int inPackets, int outPackets, int unAckedBytes);
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/// <summary>
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/// Fired when the queue for one or more packet categories is empty. This
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/// event can be hooked to put more data on the empty queues
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/// </summary>
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/// <param name="category">Categories of the packet queues that are empty</param>
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public delegate void QueueEmpty(ThrottleOutPacketTypeFlags categories);
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#endregion Delegates
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/// <summary>
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/// Tracks state for a client UDP connection and provides client-specific methods
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/// </summary>
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public sealed class LLUDPClient
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{
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// TODO: Make this a config setting
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/// <summary>Percentage of the task throttle category that is allocated to avatar and prim
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/// state updates</summary>
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const float STATE_TASK_PERCENTAGE = 0.8f;
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private static readonly ILog m_log = LogManager.GetLogger(System.Reflection.MethodBase.GetCurrentMethod().DeclaringType);
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/// <summary>The number of packet categories to throttle on. If a throttle category is added
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/// or removed, this number must also change</summary>
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const int THROTTLE_CATEGORY_COUNT = 8;
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/// <summary>Fired when updated networking stats are produced for this client</summary>
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public event PacketStats OnPacketStats;
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/// <summary>Fired when the queue for a packet category is empty. This event can be
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/// hooked to put more data on the empty queue</summary>
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public event QueueEmpty OnQueueEmpty;
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/// <summary>AgentID for this client</summary>
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public readonly UUID AgentID;
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/// <summary>The remote address of the connected client</summary>
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public readonly IPEndPoint RemoteEndPoint;
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/// <summary>Circuit code that this client is connected on</summary>
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public readonly uint CircuitCode;
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/// <summary>Sequence numbers of packets we've received (for duplicate checking)</summary>
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public readonly IncomingPacketHistoryCollection PacketArchive = new IncomingPacketHistoryCollection(200);
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/// <summary>Packets we have sent that need to be ACKed by the client</summary>
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public readonly UnackedPacketCollection NeedAcks = new UnackedPacketCollection();
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/// <summary>ACKs that are queued up, waiting to be sent to the client</summary>
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public readonly OpenSim.Framework.LocklessQueue<uint> PendingAcks = new OpenSim.Framework.LocklessQueue<uint>();
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/// <summary>Current packet sequence number</summary>
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public int CurrentSequence;
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/// <summary>Current ping sequence number</summary>
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public byte CurrentPingSequence;
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/// <summary>True when this connection is alive, otherwise false</summary>
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public bool IsConnected = true;
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/// <summary>True when this connection is paused, otherwise false</summary>
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public bool IsPaused;
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/// <summary>Environment.TickCount when the last packet was received for this client</summary>
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public int TickLastPacketReceived;
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/// <summary>Smoothed round-trip time. A smoothed average of the round-trip time for sending a
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/// reliable packet to the client and receiving an ACK</summary>
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public float SRTT;
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/// <summary>Round-trip time variance. Measures the consistency of round-trip times</summary>
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public float RTTVAR;
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/// <summary>Retransmission timeout. Packets that have not been acknowledged in this number of
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/// milliseconds or longer will be resent</summary>
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/// <remarks>Calculated from <seealso cref="SRTT"/> and <seealso cref="RTTVAR"/> using the
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/// guidelines in RFC 2988</remarks>
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public int RTO;
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/// <summary>Number of bytes received since the last acknowledgement was sent out. This is used
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/// to loosely follow the TCP delayed ACK algorithm in RFC 1122 (4.2.3.2)</summary>
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public int BytesSinceLastACK;
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/// <summary>Number of packets received from this client</summary>
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public int PacketsReceived;
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/// <summary>Number of packets sent to this client</summary>
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public int PacketsSent;
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/// <summary>Number of packets resent to this client</summary>
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public int PacketsResent;
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/// <summary>Total byte count of unacked packets sent to this client</summary>
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public int UnackedBytes;
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/// <summary>Total number of received packets that we have reported to the OnPacketStats event(s)</summary>
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private int m_packetsReceivedReported;
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/// <summary>Total number of sent packets that we have reported to the OnPacketStats event(s)</summary>
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private int m_packetsSentReported;
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/// <summary>Holds the Environment.TickCount value of when the next OnQueueEmpty can be fired</summary>
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private int m_nextOnQueueEmpty = 1;
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/// <summary>Throttle bucket for this agent's connection</summary>
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private readonly TokenBucket m_throttle;
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/// <summary>Throttle buckets for each packet category</summary>
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private readonly TokenBucket[] m_throttleCategories;
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/// <summary>Outgoing queues for throttled packets</summary>
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private readonly OpenSim.Framework.LocklessQueue<OutgoingPacket>[] m_packetOutboxes = new OpenSim.Framework.LocklessQueue<OutgoingPacket>[THROTTLE_CATEGORY_COUNT];
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/// <summary>A container that can hold one packet for each outbox, used to store
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/// dequeued packets that are being held for throttling</summary>
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private readonly OutgoingPacket[] m_nextPackets = new OutgoingPacket[THROTTLE_CATEGORY_COUNT];
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/// <summary>A reference to the LLUDPServer that is managing this client</summary>
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private readonly LLUDPServer m_udpServer;
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/// <summary>Caches packed throttle information</summary>
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private byte[] m_packedThrottles;
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private int m_defaultRTO = 3000;
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private int m_maxRTO = 60000;
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/// <summary>
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/// Default constructor
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/// </summary>
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/// <param name="server">Reference to the UDP server this client is connected to</param>
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/// <param name="rates">Default throttling rates and maximum throttle limits</param>
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/// <param name="parentThrottle">Parent HTB (hierarchical token bucket)
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/// that the child throttles will be governed by</param>
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/// <param name="circuitCode">Circuit code for this connection</param>
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/// <param name="agentID">AgentID for the connected agent</param>
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/// <param name="remoteEndPoint">Remote endpoint for this connection</param>
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public LLUDPClient(LLUDPServer server, ThrottleRates rates, TokenBucket parentThrottle, uint circuitCode, UUID agentID, IPEndPoint remoteEndPoint, int defaultRTO, int maxRTO)
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{
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AgentID = agentID;
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RemoteEndPoint = remoteEndPoint;
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CircuitCode = circuitCode;
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m_udpServer = server;
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if (defaultRTO != 0)
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m_defaultRTO = defaultRTO;
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if (maxRTO != 0)
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m_maxRTO = maxRTO;
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// Create a token bucket throttle for this client that has the scene token bucket as a parent
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m_throttle = new TokenBucket(parentThrottle, rates.TotalLimit, rates.Total);
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// Create an array of token buckets for this clients different throttle categories
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m_throttleCategories = new TokenBucket[THROTTLE_CATEGORY_COUNT];
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for (int i = 0; i < THROTTLE_CATEGORY_COUNT; i++)
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{
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ThrottleOutPacketType type = (ThrottleOutPacketType)i;
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// Initialize the packet outboxes, where packets sit while they are waiting for tokens
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m_packetOutboxes[i] = new OpenSim.Framework.LocklessQueue<OutgoingPacket>();
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// Initialize the token buckets that control the throttling for each category
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m_throttleCategories[i] = new TokenBucket(m_throttle, rates.GetLimit(type), rates.GetRate(type));
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}
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// Default the retransmission timeout to three seconds
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RTO = m_defaultRTO;
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// Initialize this to a sane value to prevent early disconnects
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TickLastPacketReceived = Environment.TickCount & Int32.MaxValue;
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}
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/// <summary>
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/// Shuts down this client connection
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/// </summary>
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public void Shutdown()
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{
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IsConnected = false;
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for (int i = 0; i < THROTTLE_CATEGORY_COUNT; i++)
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{
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m_packetOutboxes[i].Clear();
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m_nextPackets[i] = null;
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}
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OnPacketStats = null;
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OnQueueEmpty = null;
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}
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/// <summary>
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/// Gets information about this client connection
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/// </summary>
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/// <returns>Information about the client connection</returns>
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public ClientInfo GetClientInfo()
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{
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// TODO: This data structure is wrong in so many ways. Locking and copying the entire lists
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// of pending and needed ACKs for every client every time some method wants information about
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// this connection is a recipe for poor performance
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ClientInfo info = new ClientInfo();
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info.pendingAcks = new Dictionary<uint, uint>();
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info.needAck = new Dictionary<uint, byte[]>();
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info.resendThrottle = m_throttleCategories[(int)ThrottleOutPacketType.Resend].DripRate;
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info.landThrottle = m_throttleCategories[(int)ThrottleOutPacketType.Land].DripRate;
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info.windThrottle = m_throttleCategories[(int)ThrottleOutPacketType.Wind].DripRate;
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info.cloudThrottle = m_throttleCategories[(int)ThrottleOutPacketType.Cloud].DripRate;
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info.taskThrottle = m_throttleCategories[(int)ThrottleOutPacketType.State].DripRate + m_throttleCategories[(int)ThrottleOutPacketType.Task].DripRate;
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info.assetThrottle = m_throttleCategories[(int)ThrottleOutPacketType.Asset].DripRate;
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info.textureThrottle = m_throttleCategories[(int)ThrottleOutPacketType.Texture].DripRate;
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info.totalThrottle = info.resendThrottle + info.landThrottle + info.windThrottle + info.cloudThrottle +
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info.taskThrottle + info.assetThrottle + info.textureThrottle;
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return info;
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}
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/// <summary>
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/// Modifies the UDP throttles
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/// </summary>
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/// <param name="info">New throttling values</param>
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public void SetClientInfo(ClientInfo info)
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{
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// TODO: Allowing throttles to be manually set from this function seems like a reasonable
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// idea. On the other hand, letting external code manipulate our ACK accounting is not
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// going to happen
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throw new NotImplementedException();
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}
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/// <summary>
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/// Return statistics information about client packet queues.
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/// </summary>
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///
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/// FIXME: This should really be done in a more sensible manner rather than sending back a formatted string.
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///
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/// <returns></returns>
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public string GetStats()
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{
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return string.Format(
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"{0,7} {1,7} {2,7} {3,9} {4,7} {5,7} {6,7} {7,7} {8,7} {9,8} {10,7} {11,7}",
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PacketsReceived,
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PacketsSent,
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PacketsResent,
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UnackedBytes,
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m_packetOutboxes[(int)ThrottleOutPacketType.Resend].Count,
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m_packetOutboxes[(int)ThrottleOutPacketType.Land].Count,
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m_packetOutboxes[(int)ThrottleOutPacketType.Wind].Count,
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m_packetOutboxes[(int)ThrottleOutPacketType.Cloud].Count,
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m_packetOutboxes[(int)ThrottleOutPacketType.Task].Count,
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m_packetOutboxes[(int)ThrottleOutPacketType.Texture].Count,
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m_packetOutboxes[(int)ThrottleOutPacketType.Asset].Count,
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m_packetOutboxes[(int)ThrottleOutPacketType.State].Count);
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}
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public void SendPacketStats()
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{
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PacketStats callback = OnPacketStats;
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if (callback != null)
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{
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int newPacketsReceived = PacketsReceived - m_packetsReceivedReported;
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int newPacketsSent = PacketsSent - m_packetsSentReported;
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callback(newPacketsReceived, newPacketsSent, UnackedBytes);
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m_packetsReceivedReported += newPacketsReceived;
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m_packetsSentReported += newPacketsSent;
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}
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}
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public void SetThrottles(byte[] throttleData)
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{
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byte[] adjData;
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int pos = 0;
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if (!BitConverter.IsLittleEndian)
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{
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byte[] newData = new byte[7 * 4];
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Buffer.BlockCopy(throttleData, 0, newData, 0, 7 * 4);
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for (int i = 0; i < 7; i++)
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Array.Reverse(newData, i * 4, 4);
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adjData = newData;
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}
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else
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{
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adjData = throttleData;
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}
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// 0.125f converts from bits to bytes
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int resend = (int)(BitConverter.ToSingle(adjData, pos) * 0.125f); pos += 4;
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int land = (int)(BitConverter.ToSingle(adjData, pos) * 0.125f); pos += 4;
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int wind = (int)(BitConverter.ToSingle(adjData, pos) * 0.125f); pos += 4;
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int cloud = (int)(BitConverter.ToSingle(adjData, pos) * 0.125f); pos += 4;
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int task = (int)(BitConverter.ToSingle(adjData, pos) * 0.125f); pos += 4;
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int texture = (int)(BitConverter.ToSingle(adjData, pos) * 0.125f); pos += 4;
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int asset = (int)(BitConverter.ToSingle(adjData, pos) * 0.125f);
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// State is a subcategory of task that we allocate a percentage to
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int state = (int)((float)task * STATE_TASK_PERCENTAGE);
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task -= state;
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// Make sure none of the throttles are set below our packet MTU,
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// otherwise a throttle could become permanently clogged
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resend = Math.Max(resend, LLUDPServer.MTU);
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land = Math.Max(land, LLUDPServer.MTU);
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wind = Math.Max(wind, LLUDPServer.MTU);
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cloud = Math.Max(cloud, LLUDPServer.MTU);
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task = Math.Max(task, LLUDPServer.MTU);
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texture = Math.Max(texture, LLUDPServer.MTU);
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asset = Math.Max(asset, LLUDPServer.MTU);
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state = Math.Max(state, LLUDPServer.MTU);
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int total = resend + land + wind + cloud + task + texture + asset + state;
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//m_log.DebugFormat("[LLUDPCLIENT]: {0} is setting throttles. Resend={1}, Land={2}, Wind={3}, Cloud={4}, Task={5}, Texture={6}, Asset={7}, State={8}, Total={9}",
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// AgentID, resend, land, wind, cloud, task, texture, asset, state, total);
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// Update the token buckets with new throttle values
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TokenBucket bucket;
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bucket = m_throttle;
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bucket.MaxBurst = total;
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bucket = m_throttleCategories[(int)ThrottleOutPacketType.Resend];
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bucket.DripRate = resend;
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bucket.MaxBurst = resend;
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bucket = m_throttleCategories[(int)ThrottleOutPacketType.Land];
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bucket.DripRate = land;
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bucket.MaxBurst = land;
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bucket = m_throttleCategories[(int)ThrottleOutPacketType.Wind];
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bucket.DripRate = wind;
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bucket.MaxBurst = wind;
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bucket = m_throttleCategories[(int)ThrottleOutPacketType.Cloud];
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bucket.DripRate = cloud;
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bucket.MaxBurst = cloud;
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bucket = m_throttleCategories[(int)ThrottleOutPacketType.Asset];
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bucket.DripRate = asset;
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bucket.MaxBurst = asset;
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bucket = m_throttleCategories[(int)ThrottleOutPacketType.Task];
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bucket.DripRate = task + state;
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bucket.MaxBurst = task + state;
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bucket = m_throttleCategories[(int)ThrottleOutPacketType.State];
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bucket.DripRate = state;
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bucket.MaxBurst = state;
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bucket = m_throttleCategories[(int)ThrottleOutPacketType.Texture];
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bucket.DripRate = texture;
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bucket.MaxBurst = texture;
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// Reset the packed throttles cached data
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m_packedThrottles = null;
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}
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public byte[] GetThrottlesPacked()
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{
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byte[] data = m_packedThrottles;
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if (data == null)
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{
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data = new byte[7 * 4];
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int i = 0;
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Buffer.BlockCopy(Utils.FloatToBytes((float)m_throttleCategories[(int)ThrottleOutPacketType.Resend].DripRate), 0, data, i, 4); i += 4;
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Buffer.BlockCopy(Utils.FloatToBytes((float)m_throttleCategories[(int)ThrottleOutPacketType.Land].DripRate), 0, data, i, 4); i += 4;
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Buffer.BlockCopy(Utils.FloatToBytes((float)m_throttleCategories[(int)ThrottleOutPacketType.Wind].DripRate), 0, data, i, 4); i += 4;
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Buffer.BlockCopy(Utils.FloatToBytes((float)m_throttleCategories[(int)ThrottleOutPacketType.Cloud].DripRate), 0, data, i, 4); i += 4;
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Buffer.BlockCopy(Utils.FloatToBytes((float)(m_throttleCategories[(int)ThrottleOutPacketType.Task].DripRate) +
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m_throttleCategories[(int)ThrottleOutPacketType.State].DripRate), 0, data, i, 4); i += 4;
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Buffer.BlockCopy(Utils.FloatToBytes((float)m_throttleCategories[(int)ThrottleOutPacketType.Texture].DripRate), 0, data, i, 4); i += 4;
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Buffer.BlockCopy(Utils.FloatToBytes((float)m_throttleCategories[(int)ThrottleOutPacketType.Asset].DripRate), 0, data, i, 4); i += 4;
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m_packedThrottles = data;
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}
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return data;
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}
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/// <summary>
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/// Queue an outgoing packet if appropriate.
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/// </summary>
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/// <param name="packet"></param>
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/// <param name="forceQueue">Always queue the packet if at all possible.</param>
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/// <returns>
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/// true if the packet has been queued,
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/// false if the packet has not been queued and should be sent immediately.
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/// </returns>
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public bool EnqueueOutgoing(OutgoingPacket packet, bool forceQueue)
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{
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int category = (int)packet.Category;
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if (category >= 0 && category < m_packetOutboxes.Length)
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{
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OpenSim.Framework.LocklessQueue<OutgoingPacket> queue = m_packetOutboxes[category];
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TokenBucket bucket = m_throttleCategories[category];
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if (!forceQueue && bucket.RemoveTokens(packet.Buffer.DataLength))
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{
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// Enough tokens were removed from the bucket, the packet will not be queued
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return false;
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}
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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;
|
|
}
|
|
}
|
|
|
|
/// <summary>
|
|
/// Loops through all of the packet queues for this client and tries to send
|
|
/// an outgoing packet from each, obeying the throttling bucket limits
|
|
/// </summary>
|
|
///
|
|
/// <remarks>
|
|
/// 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
|
|
/// </remarks>
|
|
///
|
|
/// <returns>True if any packets were sent, otherwise false</returns>
|
|
public bool DequeueOutgoing()
|
|
{
|
|
OutgoingPacket packet;
|
|
OpenSim.Framework.LocklessQueue<OutgoingPacket> 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;
|
|
}
|
|
|
|
/// <summary>
|
|
/// 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
|
|
/// </summary>
|
|
/// <param name="r">Round-trip time of a single packet and its
|
|
/// acknowledgement</param>
|
|
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");
|
|
}
|
|
|
|
/// <summary>
|
|
/// Exponential backoff of the retransmission timeout, per section 5.5
|
|
/// of RFC 2988
|
|
/// </summary>
|
|
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);
|
|
}
|
|
|
|
/// <summary>
|
|
/// Does an early check to see if this queue empty callback is already
|
|
/// running, then asynchronously firing the event
|
|
/// </summary>
|
|
/// <param name="throttleIndex">Throttle category to fire the callback
|
|
/// for</param>
|
|
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);
|
|
}
|
|
}
|
|
|
|
/// <summary>
|
|
/// Fires the OnQueueEmpty callback and sets the minimum time that it
|
|
/// can be called again
|
|
/// </summary>
|
|
/// <param name="o">Throttle categories to fire the callback for,
|
|
/// stored as an object to match the WaitCallback delegate
|
|
/// signature</param>
|
|
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;
|
|
}
|
|
|
|
/// <summary>
|
|
/// Converts a <seealso cref="ThrottleOutPacketType"/> integer to a
|
|
/// flag value
|
|
/// </summary>
|
|
/// <param name="i">Throttle category to convert</param>
|
|
/// <returns>Flag representation of the throttle category</returns>
|
|
private static ThrottleOutPacketTypeFlags CategoryToFlag(int i)
|
|
{
|
|
ThrottleOutPacketType category = (ThrottleOutPacketType)i;
|
|
|
|
/*
|
|
* Land = 1,
|
|
/// <summary>Wind data</summary>
|
|
Wind = 2,
|
|
/// <summary>Cloud data</summary>
|
|
Cloud = 3,
|
|
/// <summary>Any packets that do not fit into the other throttles</summary>
|
|
Task = 4,
|
|
/// <summary>Texture assets</summary>
|
|
Texture = 5,
|
|
/// <summary>Non-texture assets</summary>
|
|
Asset = 6,
|
|
/// <summary>Avatar and primitive data</summary>
|
|
/// <remarks>This is a sub-category of Task</remarks>
|
|
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;
|
|
}
|
|
}
|
|
}
|
|
}
|