mcs/class/System.ComponentModel.Composition/Tests/ComponentModelUnitTest/Microsoft/Internal/Collections/ConditionalWeakTableTests.cs

   1 // -----------------------------------------------------------------------\r
   2 // Copyright (c) Microsoft Corporation.  All rights reserved.\r
   3 // -----------------------------------------------------------------------\r
   4 using System;\r
   5 using System.Collections;\r
   6 using System.Collections.Generic;\r
   7 using System.Runtime.CompilerServices;\r
   8 using System.Text;\r
   9 using System.UnitTesting;\r
  10 using Microsoft.VisualStudio.TestTools.UnitTesting;\r
  11 \r
  12 namespace Microsoft.Internal.Collections\r
  13 {\r
  14     [TestClass]\r
  15     public class ConditionalWeakTableTests\r
  16     {\r
  17         [TestMethod]\r
  18         public void Add_KeyShouldBeCollected()\r
  19         {\r
  20             var obj = new object();\r
  21             var cwt = new ConditionalWeakTable<object, object>();\r
  22 \r
  23             cwt.Add(obj, new object());\r
  24 \r
  25             var wr = new WeakReference(obj);\r
  26 \r
  27             obj = null;\r
  28 \r
  29             GC.Collect();\r
  30             GC.WaitForPendingFinalizers();\r
  31 \r
  32             Assert.IsNull(wr.Target, "Key should be collected now!");\r
  33 \r
  34             GC.KeepAlive(cwt);\r
  35         }\r
  36 \r
  37         [TestMethod]\r
  38         public void Add_KeyHeld_ValueShouldNotBeCollected()\r
  39         {\r
  40             var obj = new object();\r
  41             var str = new StringBuilder();\r
  42             var cwt = new ConditionalWeakTable<object, StringBuilder>();\r
  43 \r
  44             var wrKey = new WeakReference(obj);\r
  45             var wrValue = new WeakReference(str);\r
  46 \r
  47             cwt.Add(obj, str);\r
  48 \r
  49             str = null;\r
  50 \r
  51             GC.Collect();\r
  52             GC.WaitForPendingFinalizers();\r
  53 \r
  54             // Should still have both references\r
  55             Assert.IsNotNull(wrKey.Target, "Key should NOT be collected yet!");\r
  56             Assert.IsNotNull(wrValue.Target, "Value should NOT be collected yet!");\r
  57 \r
  58             GC.KeepAlive(obj);\r
  59             GC.KeepAlive(cwt);\r
  60         }\r
  61 \r
  62 #if CLR40\r
  63         [TestMethod]\r
  64         public void Add_KeyCollected_ValueShouldBeCollected()\r
  65         {\r
  66             var obj = new object();\r
  67             var str = new StringBuilder();\r
  68             var cwt = new ConditionalWeakTable<object, StringBuilder>();\r
  69 \r
  70             cwt.Add(obj, str);\r
  71 \r
  72             var wrKey = new WeakReference(obj);\r
  73             var wrValue = new WeakReference(str);\r
  74             str = null;\r
  75             obj = null;\r
  76 \r
  77             GC.Collect();\r
  78             GC.WaitForPendingFinalizers();\r
  79 \r
  80             Assert.IsNull(wrKey.Target, "Key should be collected now!");\r
  81             Assert.IsNull(wrValue.Target, "Value should be collected now!");\r
  82 \r
  83             GC.KeepAlive(cwt);\r
  84         }\r
  85 #endif\r
  86 \r
  87         [TestMethod]\r
  88         public void Remove_ValidKey_ShouldReturnTrue()\r
  89         {\r
  90             var obj = new object();\r
  91             var obj2 = new object();\r
  92             var cwt = new ConditionalWeakTable<object, object>();\r
  93 \r
  94             cwt.Add(obj, obj2);\r
  95 \r
  96             Assert.IsTrue(cwt.Remove(obj));\r
  97         }\r
  98 \r
  99         [TestMethod]\r
 100         public void Remove_InvalidKey_ShouldReturnTrue()\r
 101         {\r
 102             var obj = new object();\r
 103             var obj2 = new object();\r
 104             var cwt = new ConditionalWeakTable<object, object>();\r
 105 \r
 106             cwt.Add(obj, obj2);\r
 107 \r
 108             Assert.IsFalse(cwt.Remove(obj2));\r
 109         }\r
 110 \r
 111         [TestMethod]\r
 112         public void TryGetValue_ValidKey_ShouldReturnTrueAndValue()\r
 113         {\r
 114             var obj = new object();\r
 115             var obj2 = new object();\r
 116             var cwt = new ConditionalWeakTable<object, object>();\r
 117 \r
 118             cwt.Add(obj, obj2);\r
 119 \r
 120             object obj3;\r
 121             Assert.IsTrue(cwt.TryGetValue(obj, out obj3), "Should find a value with the key!");\r
 122             Assert.AreEqual(obj2, obj3);\r
 123         }\r
 124 \r
 125         [TestMethod]\r
 126         public void TryGetValue_InvalidKey_ShouldReturnFalseAndNull()\r
 127         {\r
 128             var obj = new object();\r
 129             var obj2 = new object();\r
 130             var cwt = new ConditionalWeakTable<object, object>();\r
 131 \r
 132             cwt.Add(obj, obj2);\r
 133 \r
 134             object obj3;\r
 135             Assert.IsFalse(cwt.TryGetValue(obj2, out obj3), "Should NOT find a value with the key!");\r
 136             Assert.IsNull(obj3); \r
 137         }\r
 138 \r
 139 #if !CLR40\r
 140         [TestMethod]\r
 141         public void Add_KeyValueSame_KeyShouldNotBeCollected()\r
 142         {\r
 143             // Dev10:556089 - This test demonstrations a bug in our implementation\r
 144             // of ConditionalWeakTable which needs CLR 4 support to fix so once\r
 145             // we switch to the CLR 4 version of ConditionalWeakTable this should go away.\r
 146 \r
 147             var obj = new object();\r
 148             var cwt = new ConditionalWeakTable<object, object>();\r
 149 \r
 150             cwt.Add(obj, obj);\r
 151 \r
 152             var wrKey = new WeakReference(obj);\r
 153             obj = null;\r
 154 \r
 155             GC.Collect();\r
 156             GC.WaitForPendingFinalizers();\r
 157 \r
 158             Assert.IsNotNull(wrKey.Target, "Key should NOT be collected yet!");\r
 159 \r
 160             // Apply pressure to ensure they still don't go away.\r
 161             ApplyMemoryPressureOnConditionalWeakTable(cwt);\r
 162 \r
 163             Assert.IsNotNull(wrKey.Target, "Key should NOT be collected yet!");\r
 164 \r
 165             GC.KeepAlive(cwt);\r
 166         }\r
 167 \r
 168         public class ObjectHolder\r
 169         {\r
 170             public object Obj { get; set; }\r
 171             public ObjectHolder() { }\r
 172             public ObjectHolder(object obj)\r
 173             {\r
 174                 Obj = obj;\r
 175             }\r
 176         }\r
 177 \r
 178         [TestMethod]\r
 179         public void Add_ValueReferencesKey_KeyAndValueShouldNotBeCollected()\r
 180         {\r
 181             // Dev10:556089 - This test demonstrations a bug in our implementation\r
 182             // of ConditionalWeakTable which needs CLR 4 support to fix so once\r
 183             // we switch to the CLR 4 version of ConditionalWeakTable this should go away.\r
 184 \r
 185             var obj = new object();\r
 186             var holder = new ObjectHolder(obj);\r
 187             var cwt = new ConditionalWeakTable<object, ObjectHolder>();\r
 188 \r
 189             cwt.Add(obj, holder);\r
 190 \r
 191             var wrKey = new WeakReference(obj);\r
 192             var wrValue = new WeakReference(holder);\r
 193             holder = null;\r
 194             obj = null;\r
 195 \r
 196             GC.Collect();\r
 197             GC.WaitForPendingFinalizers();\r
 198 \r
 199             Assert.IsNotNull(wrKey.Target, "Key should NOT be collected yet!");\r
 200             Assert.IsNotNull(wrValue.Target, "Value should NOT be collected now!");\r
 201 \r
 202             // Apply pressure to ensure they still don't go away.\r
 203             ApplyMemoryPressureOnConditionalWeakTable(cwt);\r
 204 \r
 205             Assert.IsNotNull(wrKey.Target, "Key should NOT be collected yet!");\r
 206             Assert.IsNotNull(wrValue.Target, "Value should NOT be collected now!");\r
 207 \r
 208             GC.KeepAlive(cwt);\r
 209         }\r
 210 \r
 211         private void ApplyMemoryPressureOnConditionalWeakTable<T,V>(ConditionalWeakTable<T,V> table)\r
 212             where T : class, new()\r
 213             where V : class, new()\r
 214         {\r
 215             // Adding 100 items should do it.\r
 216             for (int i = 0; i < 100; i++)\r
 217             {\r
 218                 table.Add(new T(), new V());\r
 219             }\r
 220 \r
 221             GC.Collect();\r
 222             GC.WaitForPendingFinalizers();\r
 223         }\r
 224 #endif //!CLR40\r
 225     }\r
 226 }\r