corrade-vassal – Blame information for rev 1
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1 | vero | 1 | /* |
2 | * Copyright (c) 2006-2014, openmetaverse.org |
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3 | * All rights reserved. |
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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 | * |
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8 | * - Redistributions of source code must retain the above copyright notice, this |
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9 | * list of conditions and the following disclaimer. |
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10 | * - Neither the name of the openmetaverse.org nor the names |
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11 | * of its contributors may be used to endorse or promote products derived from |
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12 | * this software without specific prior written permission. |
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13 | * |
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14 | * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" |
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15 | * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
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16 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
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17 | * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE |
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18 | * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR |
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19 | * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF |
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20 | * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS |
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21 | * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN |
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22 | * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) |
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23 | * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE |
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24 | * POSSIBILITY OF SUCH DAMAGE. |
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25 | */ |
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26 | |||
27 | using System; |
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28 | using System.Collections; |
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29 | using System.Collections.Generic; |
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30 | using System.Threading; |
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31 | |||
32 | namespace OpenMetaverse |
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33 | { |
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34 | public sealed class WrappedObject<T> : IDisposable where T : class |
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35 | { |
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36 | private T _instance; |
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37 | internal readonly ObjectPoolSegment<T> _owningSegment; |
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38 | internal readonly ObjectPoolBase<T> _owningObjectPool; |
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39 | private bool _disposed = false; |
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40 | |||
41 | internal WrappedObject(ObjectPoolBase<T> owningPool, ObjectPoolSegment<T> ownerSegment, T activeInstance) |
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42 | { |
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43 | _owningObjectPool = owningPool; |
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44 | _owningSegment = ownerSegment; |
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45 | _instance = activeInstance; |
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46 | } |
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47 | |||
48 | ~WrappedObject() |
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49 | { |
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50 | #if !PocketPC |
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51 | // If the AppDomain is being unloaded, or the CLR is |
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52 | // shutting down, just exit gracefully |
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53 | if (Environment.HasShutdownStarted) |
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54 | return; |
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55 | #endif |
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56 | |||
57 | // Object Resurrection in Action! |
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58 | GC.ReRegisterForFinalize(this); |
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59 | |||
60 | // Return this instance back to the owning queue |
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61 | _owningObjectPool.CheckIn(_owningSegment, _instance); |
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62 | } |
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63 | |||
64 | /// <summary> |
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65 | /// Returns an instance of the class that has been checked out of the Object Pool. |
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66 | /// </summary> |
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67 | public T Instance |
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68 | { |
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69 | get |
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70 | { |
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71 | if (_disposed) |
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72 | throw new ObjectDisposedException("WrappedObject"); |
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73 | return _instance; |
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74 | } |
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75 | } |
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76 | |||
77 | /// <summary> |
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78 | /// Checks the instance back into the object pool |
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79 | /// </summary> |
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80 | public void Dispose() |
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81 | { |
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82 | if (_disposed) |
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83 | return; |
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84 | |||
85 | _disposed = true; |
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86 | _owningObjectPool.CheckIn(_owningSegment, _instance); |
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87 | GC.SuppressFinalize(this); |
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88 | } |
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89 | } |
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90 | |||
91 | public abstract class ObjectPoolBase<T> : IDisposable where T : class |
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92 | { |
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93 | private int _itemsPerSegment = 32; |
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94 | private int _minimumSegmentCount = 1; |
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95 | |||
96 | // A segment won't be eligible for cleanup unless it's at least this old... |
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97 | private TimeSpan _minimumAgeToCleanup = new TimeSpan(0, 5, 0); |
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98 | |||
99 | // ever increasing segment counter |
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100 | private int _activeSegment = 0; |
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101 | |||
102 | private bool _gc = true; |
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103 | |||
104 | private volatile bool _disposed = false; |
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105 | |||
106 | private Dictionary<int, ObjectPoolSegment<T>> _segments = new Dictionary<int, ObjectPoolSegment<T>>(); |
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107 | private object _syncRoot = new object(); |
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108 | private object _timerLock = new object(); |
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109 | |||
110 | // create a timer that starts in 5 minutes, and gets called every 5 minutes. |
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111 | System.Threading.Timer _timer; |
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112 | int _cleanupFrequency; |
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113 | |||
114 | /// <summary> |
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115 | /// Creates a new instance of the ObjectPoolBase class. Initialize MUST be called |
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116 | /// after using this constructor. |
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117 | /// </summary> |
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118 | protected ObjectPoolBase() |
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119 | { |
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120 | } |
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121 | |||
122 | /// <summary> |
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123 | /// Creates a new instance of the ObjectPool Base class. |
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124 | /// </summary> |
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125 | /// <param name="itemsPerSegment">The object pool is composed of segments, which |
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126 | /// are allocated whenever the size of the pool is exceeded. The number of items |
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127 | /// in a segment should be large enough that allocating a new segmeng is a rare |
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128 | /// thing. For example, on a server that will have 10k people logged in at once, |
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129 | /// the receive buffer object pool should have segment sizes of at least 1000 |
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130 | /// byte arrays per segment. |
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131 | /// </param> |
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132 | /// <param name="minimumSegmentCount">The minimun number of segments that may exist.</param> |
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133 | /// <param name="gcOnPoolGrowth">Perform a full GC.Collect whenever a segment is allocated, and then again after allocation to compact the heap.</param> |
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134 | /// <param name="cleanupFrequenceMS">The frequency which segments are checked to see if they're eligible for cleanup.</param> |
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135 | protected ObjectPoolBase(int itemsPerSegment, int minimumSegmentCount, bool gcOnPoolGrowth, int cleanupFrequenceMS) |
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136 | { |
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137 | Initialize(itemsPerSegment, minimumSegmentCount, gcOnPoolGrowth, cleanupFrequenceMS); |
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138 | } |
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139 | |||
140 | protected void Initialize(int itemsPerSegment, int minimumSegmentCount, bool gcOnPoolGrowth, int cleanupFrequenceMS) |
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141 | { |
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142 | _itemsPerSegment = itemsPerSegment; |
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143 | _minimumSegmentCount = minimumSegmentCount; |
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144 | _gc = gcOnPoolGrowth; |
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145 | |||
146 | // force garbage collection to make sure these new long lived objects |
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147 | // cause as little fragmentation as possible |
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148 | if (_gc) |
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149 | System.GC.Collect(); |
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150 | |||
151 | lock (_syncRoot) |
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152 | { |
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153 | while (_segments.Count < this.MinimumSegmentCount) |
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154 | { |
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155 | ObjectPoolSegment<T> segment = CreateSegment(false); |
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156 | _segments.Add(segment.SegmentNumber, segment); |
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157 | } |
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158 | } |
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159 | |||
160 | // This forces a compact, to make sure our objects fill in any holes in the heap. |
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161 | if (_gc) |
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162 | { |
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163 | System.GC.Collect(); |
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164 | } |
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165 | |||
166 | _timer = new Timer(CleanupThreadCallback, null, cleanupFrequenceMS, cleanupFrequenceMS); |
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167 | } |
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168 | |||
169 | /// <summary> |
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170 | /// Forces the segment cleanup algorithm to be run. This method is intended |
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171 | /// primarly for use from the Unit Test libraries. |
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172 | /// </summary> |
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173 | internal void ForceCleanup() |
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174 | { |
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175 | CleanupThreadCallback(null); |
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176 | } |
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177 | |||
178 | private void CleanupThreadCallback(object state) |
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179 | { |
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180 | if (_disposed) |
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181 | return; |
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182 | |||
183 | if (Monitor.TryEnter(_timerLock) == false) |
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184 | return; |
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185 | |||
186 | try |
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187 | { |
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188 | lock (_syncRoot) |
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189 | { |
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190 | // If we're below, or at, or minimum segment count threshold, |
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191 | // there's no point in going any further. |
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192 | if (_segments.Count <= _minimumSegmentCount) |
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193 | return; |
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194 | |||
195 | for (int i = _activeSegment; i > 0; i--) |
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196 | { |
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197 | ObjectPoolSegment<T> segment; |
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198 | if (_segments.TryGetValue(i, out segment) == true) |
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199 | { |
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200 | // For the "old" segments that were allocated at startup, this will |
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201 | // always be false, as their expiration dates are set at infinity. |
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202 | if (segment.CanBeCleanedUp()) |
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203 | { |
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204 | _segments.Remove(i); |
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205 | segment.Dispose(); |
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206 | } |
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207 | } |
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208 | } |
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209 | } |
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210 | } |
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211 | finally |
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212 | { |
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213 | Monitor.Exit(_timerLock); |
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214 | } |
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215 | } |
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216 | |||
217 | /// <summary> |
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218 | /// Responsible for allocate 1 instance of an object that will be stored in a segment. |
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219 | /// </summary> |
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220 | /// <returns>An instance of whatever objec the pool is pooling.</returns> |
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221 | protected abstract T GetObjectInstance(); |
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222 | |||
223 | |||
224 | private ObjectPoolSegment<T> CreateSegment(bool allowSegmentToBeCleanedUp) |
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225 | { |
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226 | if (_disposed) |
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227 | throw new ObjectDisposedException("ObjectPoolBase"); |
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228 | |||
229 | if (allowSegmentToBeCleanedUp) |
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230 | Logger.Log("Creating new object pool segment", Helpers.LogLevel.Info); |
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231 | |||
232 | // This method is called inside a lock, so no interlocked stuff required. |
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233 | int segmentToAdd = _activeSegment; |
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234 | _activeSegment++; |
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235 | |||
236 | Queue<T> buffers = new Queue<T>(); |
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237 | for (int i = 1; i <= this._itemsPerSegment; i++) |
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238 | { |
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239 | T obj = GetObjectInstance(); |
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240 | buffers.Enqueue(obj); |
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241 | } |
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242 | |||
243 | // certain segments we don't want to ever be cleaned up (the initial segments) |
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244 | DateTime cleanupTime = (allowSegmentToBeCleanedUp) ? DateTime.Now.Add(this._minimumAgeToCleanup) : DateTime.MaxValue; |
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245 | ObjectPoolSegment<T> segment = new ObjectPoolSegment<T>(segmentToAdd, buffers, cleanupTime); |
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246 | |||
247 | return segment; |
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248 | } |
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249 | |||
250 | |||
251 | /// <summary> |
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252 | /// Checks in an instance of T owned by the object pool. This method is only intended to be called |
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253 | /// by the <c>WrappedObject</c> class. |
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254 | /// </summary> |
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255 | /// <param name="owningSegment">The segment from which the instance is checked out.</param> |
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256 | /// <param name="instance">The instance of <c>T</c> to check back into the segment.</param> |
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257 | internal void CheckIn(ObjectPoolSegment<T> owningSegment, T instance) |
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258 | { |
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259 | lock (_syncRoot) |
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260 | { |
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261 | owningSegment.CheckInObject(instance); |
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262 | } |
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263 | } |
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264 | |||
265 | /// <summary> |
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266 | /// Checks an instance of <c>T</c> from the pool. If the pool is not sufficient to |
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267 | /// allow the checkout, a new segment is created. |
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268 | /// </summary> |
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269 | /// <returns>A <c>WrappedObject</c> around the instance of <c>T</c>. To check |
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270 | /// the instance back into the segment, be sureto dispose the WrappedObject |
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271 | /// when finished. </returns> |
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272 | public WrappedObject<T> CheckOut() |
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273 | { |
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274 | if (_disposed) |
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275 | throw new ObjectDisposedException("ObjectPoolBase"); |
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276 | |||
277 | // It's key that this CheckOut always, always, uses a pooled object |
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278 | // from the oldest available segment. This will help keep the "newer" |
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279 | // segments from being used - which in turn, makes them eligible |
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280 | // for deletion. |
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281 | |||
282 | |||
283 | lock (_syncRoot) |
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284 | { |
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285 | ObjectPoolSegment<T> targetSegment = null; |
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286 | |||
287 | // find the oldest segment that has items available for checkout |
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288 | for (int i = 0; i < _activeSegment; i++) |
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289 | { |
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290 | ObjectPoolSegment<T> segment; |
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291 | if (_segments.TryGetValue(i, out segment) == true) |
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292 | { |
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293 | if (segment.AvailableItems > 0) |
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294 | { |
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295 | targetSegment = segment; |
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296 | break; |
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297 | } |
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298 | } |
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299 | } |
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300 | |||
301 | if (targetSegment == null) |
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302 | { |
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303 | // We couldn't find a sigment that had any available space in it, |
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304 | // so it's time to create a new segment. |
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305 | |||
306 | // Before creating the segment, do a GC to make sure the heap |
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307 | // is compacted. |
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308 | if (_gc) GC.Collect(); |
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309 | |||
310 | targetSegment = CreateSegment(true); |
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311 | |||
312 | if (_gc) GC.Collect(); |
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313 | |||
314 | _segments.Add(targetSegment.SegmentNumber, targetSegment); |
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315 | } |
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316 | |||
317 | WrappedObject<T> obj = new WrappedObject<T>(this, targetSegment, targetSegment.CheckOutObject()); |
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318 | return obj; |
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319 | } |
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320 | } |
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321 | |||
322 | /// <summary> |
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323 | /// The total number of segments created. Intended to be used by the Unit Tests. |
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324 | /// </summary> |
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325 | public int TotalSegments |
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326 | { |
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327 | get |
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328 | { |
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329 | if (_disposed) |
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330 | throw new ObjectDisposedException("ObjectPoolBase"); |
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331 | |||
332 | lock (_syncRoot) |
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333 | { |
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334 | return _segments.Count; |
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335 | } |
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336 | } |
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337 | } |
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338 | |||
339 | /// <summary> |
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340 | /// The number of items that are in a segment. Items in a segment |
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341 | /// are all allocated at the same time, and are hopefully close to |
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342 | /// each other in the managed heap. |
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343 | /// </summary> |
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344 | public int ItemsPerSegment |
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345 | { |
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346 | get |
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347 | { |
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348 | if (_disposed) |
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349 | throw new ObjectDisposedException("ObjectPoolBase"); |
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350 | |||
351 | return _itemsPerSegment; |
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352 | } |
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353 | } |
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354 | |||
355 | /// <summary> |
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356 | /// The minimum number of segments. When segments are reclaimed, |
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357 | /// this number of segments will always be left alone. These |
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358 | /// segments are allocated at startup. |
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359 | /// </summary> |
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360 | public int MinimumSegmentCount |
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361 | { |
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362 | get |
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363 | { |
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364 | if (_disposed) |
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365 | throw new ObjectDisposedException("ObjectPoolBase"); |
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366 | |||
367 | return _minimumSegmentCount; |
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368 | } |
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369 | } |
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370 | |||
371 | /// <summary> |
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372 | /// The age a segment must be before it's eligible for cleanup. |
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373 | /// This is used to prevent thrash, and typical values are in |
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374 | /// the 5 minute range. |
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375 | /// </summary> |
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376 | public TimeSpan MinimumSegmentAgePriorToCleanup |
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377 | { |
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378 | get |
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379 | { |
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380 | if (_disposed) |
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381 | throw new ObjectDisposedException("ObjectPoolBase"); |
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382 | |||
383 | return _minimumAgeToCleanup; |
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384 | } |
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385 | set |
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386 | { |
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387 | if (_disposed) |
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388 | throw new ObjectDisposedException("ObjectPoolBase"); |
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389 | |||
390 | _minimumAgeToCleanup = value; |
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391 | } |
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392 | } |
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393 | |||
394 | /// <summary> |
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395 | /// The frequence which the cleanup thread runs. This is typically |
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396 | /// expected to be in the 5 minute range. |
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397 | /// </summary> |
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398 | public int CleanupFrequencyMilliseconds |
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399 | { |
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400 | get |
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401 | { |
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402 | if (_disposed) |
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403 | throw new ObjectDisposedException("ObjectPoolBase"); |
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404 | |||
405 | return _cleanupFrequency; |
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406 | } |
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407 | set |
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408 | { |
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409 | if (_disposed) |
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410 | throw new ObjectDisposedException("ObjectPoolBase"); |
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411 | |||
412 | Interlocked.Exchange(ref _cleanupFrequency, value); |
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413 | |||
414 | _timer.Change(_cleanupFrequency, _cleanupFrequency); |
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415 | } |
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416 | } |
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417 | |||
418 | #region IDisposable Members |
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419 | |||
420 | public void Dispose() |
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421 | { |
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422 | if (_disposed) |
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423 | return; |
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424 | |||
425 | Dispose(true); |
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426 | |||
427 | GC.SuppressFinalize(this); |
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428 | } |
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429 | |||
430 | protected virtual void Dispose(bool disposing) |
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431 | { |
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432 | if (disposing) |
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433 | { |
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434 | lock (_syncRoot) |
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435 | { |
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436 | if (_disposed) |
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437 | return; |
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438 | |||
439 | _timer.Dispose(); |
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440 | _disposed = true; |
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441 | |||
442 | foreach (KeyValuePair<int, ObjectPoolSegment<T>> kvp in _segments) |
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443 | { |
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444 | try |
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445 | { |
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446 | kvp.Value.Dispose(); |
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447 | } |
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448 | catch (Exception) { } |
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449 | } |
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450 | |||
451 | _segments.Clear(); |
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452 | } |
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453 | } |
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454 | } |
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455 | |||
456 | #endregion |
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457 | } |
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458 | |||
459 | internal class ObjectPoolSegment<T> : IDisposable where T : class |
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460 | { |
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461 | private Queue<T> _liveInstances = new Queue<T>(); |
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462 | private int _segmentNumber; |
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463 | private int _originalCount; |
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464 | private bool _isDisposed = false; |
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465 | private DateTime _eligibleForDeletionAt; |
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466 | |||
467 | public int SegmentNumber { get { return _segmentNumber; } } |
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468 | public int AvailableItems { get { return _liveInstances.Count; } } |
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469 | public DateTime DateEligibleForDeletion { get { return _eligibleForDeletionAt; } } |
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470 | |||
471 | public ObjectPoolSegment(int segmentNumber, Queue<T> liveInstances, DateTime eligibleForDeletionAt) |
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472 | { |
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473 | _segmentNumber = segmentNumber; |
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474 | _liveInstances = liveInstances; |
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475 | _originalCount = liveInstances.Count; |
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476 | _eligibleForDeletionAt = eligibleForDeletionAt; |
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477 | } |
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478 | |||
479 | public bool CanBeCleanedUp() |
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480 | { |
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481 | if (_isDisposed == true) |
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482 | throw new ObjectDisposedException("ObjectPoolSegment"); |
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483 | |||
484 | return ((_originalCount == _liveInstances.Count) && (DateTime.Now > _eligibleForDeletionAt)); |
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485 | } |
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486 | |||
487 | public void Dispose() |
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488 | { |
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489 | if (_isDisposed) |
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490 | return; |
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491 | |||
492 | _isDisposed = true; |
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493 | |||
494 | bool shouldDispose = (typeof(T) is IDisposable); |
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495 | while (_liveInstances.Count != 0) |
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496 | { |
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497 | T instance = _liveInstances.Dequeue(); |
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498 | if (shouldDispose) |
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499 | { |
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500 | try |
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501 | { |
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502 | (instance as IDisposable).Dispose(); |
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503 | } |
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504 | catch (Exception) { } |
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505 | } |
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506 | } |
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507 | } |
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508 | |||
509 | internal void CheckInObject(T o) |
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510 | { |
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511 | if (_isDisposed == true) |
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512 | throw new ObjectDisposedException("ObjectPoolSegment"); |
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513 | |||
514 | _liveInstances.Enqueue(o); |
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515 | } |
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516 | |||
517 | internal T CheckOutObject() |
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518 | { |
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519 | if (_isDisposed == true) |
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520 | throw new ObjectDisposedException("ObjectPoolSegment"); |
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521 | |||
522 | if (0 == _liveInstances.Count) |
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523 | throw new InvalidOperationException("No Objects Available for Checkout"); |
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524 | |||
525 | T o = _liveInstances.Dequeue(); |
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526 | return o; |
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527 | } |
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528 | } |
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529 | } |