opensim-development – Blame information for rev 1
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1 | eva | 1 | /* |
2 | * Copyright (c) Contributors, http://opensimulator.org/ |
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3 | * See CONTRIBUTORS.TXT for a full list of copyright holders. |
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4 | * |
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5 | * Redistribution and use in source and binary forms, with or without |
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6 | * modification, are permitted provided that the following conditions are met: |
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7 | * * Redistributions of source code must retain the above copyright |
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8 | * notice, this list of conditions and the following disclaimer. |
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9 | * * Redistributions in binary form must reproduce the above copyright |
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10 | * notice, this list of conditions and the following disclaimer in the |
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11 | * documentation and/or other materials provided with the distribution. |
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12 | * * Neither the name of the OpenSimulator Project nor the |
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13 | * names of its contributors may be used to endorse or promote products |
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14 | * derived from this software without specific prior written permission. |
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15 | * |
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16 | * THIS SOFTWARE IS PROVIDED BY THE DEVELOPERS ``AS IS'' AND ANY |
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17 | * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED |
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18 | * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE |
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19 | * DISCLAIMED. IN NO EVENT SHALL THE CONTRIBUTORS BE LIABLE FOR ANY |
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20 | * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES |
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21 | * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; |
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22 | * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND |
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23 | * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
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24 | * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS |
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25 | * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
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26 | */ |
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27 | |||
28 | using System; |
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29 | using System.Collections.Generic; |
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30 | using System.Net; |
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31 | using System.Reflection; |
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32 | using System.Threading; |
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33 | using OpenMetaverse; |
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34 | using log4net; |
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35 | using Nini.Config; |
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36 | using OpenSim.Framework; |
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37 | using OpenSim.Framework.Capabilities; |
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38 | using OpenSim.Framework.Client; |
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39 | using OpenSim.Region.Framework.Interfaces; |
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40 | using OpenSim.Region.Framework.Scenes; |
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41 | using OpenSim.Region.Physics.Manager; |
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42 | using OpenSim.Services.Interfaces; |
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43 | using GridRegion = OpenSim.Services.Interfaces.GridRegion; |
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44 | |||
45 | namespace OpenSim.Region.CoreModules.Framework.EntityTransfer |
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46 | { |
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47 | /// <summary> |
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48 | /// The possible states that an agent can be in when its being transferred between regions. |
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49 | /// </summary> |
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50 | /// <remarks> |
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51 | /// This is a state machine. |
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52 | /// |
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53 | /// [Entry] => Preparing |
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54 | /// Preparing => { Transferring || Cancelling || CleaningUp || Aborting || [Exit] } |
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55 | /// Transferring => { ReceivedAtDestination || Cancelling || CleaningUp || Aborting } |
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56 | /// Cancelling => CleaningUp || Aborting |
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57 | /// ReceivedAtDestination => CleaningUp || Aborting |
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58 | /// CleaningUp => [Exit] |
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59 | /// Aborting => [Exit] |
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60 | /// |
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61 | /// In other words, agents normally travel throwing Preparing => Transferring => ReceivedAtDestination => CleaningUp |
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62 | /// However, any state can transition to CleaningUp if the teleport has failed. |
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63 | /// </remarks> |
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64 | enum AgentTransferState |
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65 | { |
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66 | Preparing, // The agent is being prepared for transfer |
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67 | Transferring, // The agent is in the process of being transferred to a destination |
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68 | ReceivedAtDestination, // The destination has notified us that the agent has been successfully received |
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69 | CleaningUp, // The agent is being changed to child/removed after a transfer |
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70 | Cancelling, // The user has cancelled the teleport but we have yet to act upon this. |
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71 | Aborting // The transfer is aborting. Unlike Cancelling, no compensating actions should be performed |
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72 | } |
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73 | |||
74 | /// <summary> |
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75 | /// Records the state of entities when they are in transfer within or between regions (cross or teleport). |
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76 | /// </summary> |
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77 | public class EntityTransferStateMachine |
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78 | { |
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79 | private static readonly ILog m_log = LogManager.GetLogger(MethodBase.GetCurrentMethod().DeclaringType); |
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80 | private static readonly string LogHeader = "[ENTITY TRANSFER STATE MACHINE]"; |
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81 | |||
82 | /// <summary> |
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83 | /// If true then on a teleport, the source region waits for a callback from the destination region. If |
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84 | /// a callback fails to arrive within a set time then the user is pulled back into the source region. |
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85 | /// </summary> |
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86 | public bool EnableWaitForAgentArrivedAtDestination { get; set; } |
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87 | |||
88 | private EntityTransferModule m_mod; |
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89 | |||
90 | private Dictionary<UUID, AgentTransferState> m_agentsInTransit = new Dictionary<UUID, AgentTransferState>(); |
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91 | |||
92 | public EntityTransferStateMachine(EntityTransferModule module) |
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93 | { |
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94 | m_mod = module; |
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95 | } |
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96 | |||
97 | /// <summary> |
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98 | /// Set that an agent is in transit. |
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99 | /// </summary> |
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100 | /// <param name='id'>The ID of the agent being teleported</param> |
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101 | /// <returns>true if the agent was not already in transit, false if it was</returns> |
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102 | internal bool SetInTransit(UUID id) |
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103 | { |
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104 | m_log.DebugFormat("{0} SetInTransit. agent={1}, newState=Preparing", LogHeader, id); |
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105 | lock (m_agentsInTransit) |
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106 | { |
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107 | if (!m_agentsInTransit.ContainsKey(id)) |
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108 | { |
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109 | m_agentsInTransit[id] = AgentTransferState.Preparing; |
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110 | return true; |
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111 | } |
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112 | } |
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113 | |||
114 | return false; |
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115 | } |
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116 | |||
117 | /// <summary> |
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118 | /// Updates the state of an agent that is already in transit. |
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119 | /// </summary> |
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120 | /// <param name='id'></param> |
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121 | /// <param name='newState'></param> |
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122 | /// <returns></returns> |
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123 | /// <exception cref='Exception'>Illegal transitions will throw an Exception</exception> |
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124 | internal bool UpdateInTransit(UUID id, AgentTransferState newState) |
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125 | { |
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126 | m_log.DebugFormat("{0} UpdateInTransit. agent={1}, newState={2}", LogHeader, id, newState); |
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127 | |||
128 | bool transitionOkay = false; |
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129 | |||
130 | // We don't want to throw an exception on cancel since this can come it at any time. |
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131 | bool failIfNotOkay = true; |
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132 | |||
133 | // Should be a failure message if failure is not okay. |
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134 | string failureMessage = null; |
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135 | |||
136 | AgentTransferState? oldState = null; |
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137 | |||
138 | lock (m_agentsInTransit) |
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139 | { |
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140 | // Illegal to try and update an agent that's not actually in transit. |
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141 | if (!m_agentsInTransit.ContainsKey(id)) |
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142 | { |
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143 | if (newState != AgentTransferState.Cancelling && newState != AgentTransferState.Aborting) |
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144 | failureMessage = string.Format( |
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145 | "Agent with ID {0} is not registered as in transit in {1}", |
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146 | id, m_mod.Scene.RegionInfo.RegionName); |
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147 | else |
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148 | failIfNotOkay = false; |
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149 | } |
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150 | else |
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151 | { |
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152 | oldState = m_agentsInTransit[id]; |
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153 | |||
154 | if (newState == AgentTransferState.Aborting) |
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155 | { |
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156 | transitionOkay = true; |
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157 | } |
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158 | else if (newState == AgentTransferState.CleaningUp && oldState != AgentTransferState.CleaningUp) |
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159 | { |
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160 | transitionOkay = true; |
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161 | } |
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162 | else if (newState == AgentTransferState.Transferring && oldState == AgentTransferState.Preparing) |
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163 | { |
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164 | transitionOkay = true; |
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165 | } |
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166 | else if (newState == AgentTransferState.ReceivedAtDestination && oldState == AgentTransferState.Transferring) |
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167 | { |
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168 | transitionOkay = true; |
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169 | } |
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170 | else |
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171 | { |
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172 | if (newState == AgentTransferState.Cancelling |
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173 | && (oldState == AgentTransferState.Preparing || oldState == AgentTransferState.Transferring)) |
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174 | { |
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175 | transitionOkay = true; |
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176 | } |
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177 | else |
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178 | { |
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179 | failIfNotOkay = false; |
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180 | } |
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181 | } |
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182 | |||
183 | if (!transitionOkay) |
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184 | failureMessage |
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185 | = string.Format( |
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186 | "Agent with ID {0} is not allowed to move from old transit state {1} to new state {2} in {3}", |
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187 | id, oldState, newState, m_mod.Scene.RegionInfo.RegionName); |
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188 | } |
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189 | |||
190 | if (transitionOkay) |
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191 | { |
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192 | m_agentsInTransit[id] = newState; |
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193 | |||
194 | // m_log.DebugFormat( |
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195 | // "[ENTITY TRANSFER STATE MACHINE]: Changed agent with id {0} from state {1} to {2} in {3}", |
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196 | // id, oldState, newState, m_mod.Scene.Name); |
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197 | } |
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198 | else if (failIfNotOkay) |
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199 | { |
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200 | m_log.DebugFormat("{0} UpdateInTransit. Throwing transition failure = {1}", LogHeader, failureMessage); |
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201 | throw new Exception(failureMessage); |
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202 | } |
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203 | // else |
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204 | // { |
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205 | // if (oldState != null) |
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206 | // m_log.DebugFormat( |
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207 | // "[ENTITY TRANSFER STATE MACHINE]: Ignored change of agent with id {0} from state {1} to {2} in {3}", |
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208 | // id, oldState, newState, m_mod.Scene.Name); |
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209 | // else |
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210 | // m_log.DebugFormat( |
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211 | // "[ENTITY TRANSFER STATE MACHINE]: Ignored change of agent with id {0} to state {1} in {2} since agent not in transit", |
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212 | // id, newState, m_mod.Scene.Name); |
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213 | // } |
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214 | } |
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215 | |||
216 | return transitionOkay; |
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217 | } |
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218 | |||
219 | /// <summary> |
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220 | /// Gets the current agent transfer state. |
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221 | /// </summary> |
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222 | /// <returns>Null if the agent is not in transit</returns> |
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223 | /// <param name='id'> |
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224 | /// Identifier. |
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225 | /// </param> |
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226 | internal AgentTransferState? GetAgentTransferState(UUID id) |
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227 | { |
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228 | lock (m_agentsInTransit) |
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229 | { |
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230 | if (!m_agentsInTransit.ContainsKey(id)) |
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231 | return null; |
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232 | else |
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233 | return m_agentsInTransit[id]; |
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234 | } |
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235 | } |
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236 | |||
237 | /// <summary> |
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238 | /// Removes an agent from the transit state machine. |
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239 | /// </summary> |
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240 | /// <param name='id'></param> |
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241 | /// <returns>true if the agent was flagged as being teleported when this method was called, false otherwise</returns> |
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242 | internal bool ResetFromTransit(UUID id) |
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243 | { |
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244 | lock (m_agentsInTransit) |
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245 | { |
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246 | if (m_agentsInTransit.ContainsKey(id)) |
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247 | { |
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248 | AgentTransferState state = m_agentsInTransit[id]; |
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249 | |||
250 | if (state == AgentTransferState.Transferring || state == AgentTransferState.ReceivedAtDestination) |
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251 | { |
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252 | // FIXME: For now, we allow exit from any state since a thrown exception in teleport is now guranteed |
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253 | // to be handled properly - ResetFromTransit() could be invoked at any step along the process |
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254 | m_log.WarnFormat( |
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255 | "[ENTITY TRANSFER STATE MACHINE]: Agent with ID {0} should not exit directly from state {1}, should go to {2} state first in {3}", |
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256 | id, state, AgentTransferState.CleaningUp, m_mod.Scene.RegionInfo.RegionName); |
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257 | |||
258 | // throw new Exception( |
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259 | // "Agent with ID {0} cannot exit directly from state {1}, it must go to {2} state first", |
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260 | // state, AgentTransferState.CleaningUp); |
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261 | } |
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262 | |||
263 | m_agentsInTransit.Remove(id); |
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264 | |||
265 | m_log.DebugFormat( |
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266 | "[ENTITY TRANSFER STATE MACHINE]: Agent {0} cleared from transit in {1}", |
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267 | id, m_mod.Scene.RegionInfo.RegionName); |
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268 | |||
269 | return true; |
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270 | } |
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271 | } |
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272 | |||
273 | m_log.WarnFormat( |
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274 | "[ENTITY TRANSFER STATE MACHINE]: Agent {0} requested to clear from transit in {1} but was already cleared", |
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275 | id, m_mod.Scene.RegionInfo.RegionName); |
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276 | |||
277 | return false; |
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278 | } |
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279 | |||
280 | internal bool WaitForAgentArrivedAtDestination(UUID id) |
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281 | { |
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282 | if (!m_mod.WaitForAgentArrivedAtDestination) |
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283 | return true; |
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284 | |||
285 | lock (m_agentsInTransit) |
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286 | { |
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287 | AgentTransferState? currentState = GetAgentTransferState(id); |
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288 | |||
289 | if (currentState == null) |
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290 | throw new Exception( |
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291 | string.Format( |
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292 | "Asked to wait for destination callback for agent with ID {0} in {1} but agent is not in transit", |
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293 | id, m_mod.Scene.RegionInfo.RegionName)); |
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294 | |||
295 | if (currentState != AgentTransferState.Transferring && currentState != AgentTransferState.ReceivedAtDestination) |
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296 | throw new Exception( |
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297 | string.Format( |
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298 | "Asked to wait for destination callback for agent with ID {0} in {1} but agent is in state {2}", |
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299 | id, m_mod.Scene.RegionInfo.RegionName, currentState)); |
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300 | } |
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301 | |||
302 | int count = 200; |
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303 | |||
304 | // There should be no race condition here since no other code should be removing the agent transfer or |
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305 | // changing the state to another other than Transferring => ReceivedAtDestination. |
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306 | |||
307 | while (count-- > 0) |
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308 | { |
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309 | lock (m_agentsInTransit) |
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310 | { |
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311 | if (m_agentsInTransit[id] == AgentTransferState.ReceivedAtDestination) |
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312 | break; |
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313 | } |
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314 | |||
315 | // m_log.Debug(" >>> Waiting... " + count); |
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316 | Thread.Sleep(100); |
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317 | } |
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318 | |||
319 | return count > 0; |
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320 | } |
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321 | |||
322 | internal void SetAgentArrivedAtDestination(UUID id) |
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323 | { |
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324 | lock (m_agentsInTransit) |
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325 | { |
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326 | if (!m_agentsInTransit.ContainsKey(id)) |
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327 | { |
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328 | m_log.WarnFormat( |
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329 | "[ENTITY TRANSFER STATE MACHINE]: Region {0} received notification of arrival in destination of agent {1} but no teleport request is active", |
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330 | m_mod.Scene.RegionInfo.RegionName, id); |
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331 | |||
332 | return; |
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333 | } |
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334 | |||
335 | AgentTransferState currentState = m_agentsInTransit[id]; |
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336 | |||
337 | if (currentState == AgentTransferState.ReceivedAtDestination) |
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338 | { |
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339 | // An anomoly but don't make this an outright failure - destination region could be overzealous in sending notification. |
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340 | m_log.WarnFormat( |
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341 | "[ENTITY TRANSFER STATE MACHINE]: Region {0} received notification of arrival in destination of agent {1} but notification has already previously been received", |
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342 | m_mod.Scene.RegionInfo.RegionName, id); |
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343 | } |
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344 | else if (currentState != AgentTransferState.Transferring) |
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345 | { |
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346 | m_log.ErrorFormat( |
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347 | "[ENTITY TRANSFER STATE MACHINE]: Region {0} received notification of arrival in destination of agent {1} but agent is in state {2}", |
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348 | m_mod.Scene.RegionInfo.RegionName, id, currentState); |
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349 | |||
350 | return; |
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351 | } |
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352 | |||
353 | m_agentsInTransit[id] = AgentTransferState.ReceivedAtDestination; |
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354 | } |
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355 | } |
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356 | } |
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357 | } |