5 // Miguel de Icaza (miguel@ximian.com)
6 // Gonzalo Paniagua Javier (gonzalo@ximian.com)
8 // (C) Ximian, Inc. http://www.ximian.com
9 // (C) 2003 Novell, Inc. http://www.novell.com
13 // Copyright (C) 2004 Novell, Inc (http://www.novell.com)
15 // Permission is hereby granted, free of charge, to any person obtaining
16 // a copy of this software and associated documentation files (the
17 // "Software"), to deal in the Software without restriction, including
18 // without limitation the rights to use, copy, modify, merge, publish,
19 // distribute, sublicense, and/or sell copies of the Software, and to
20 // permit persons to whom the Software is furnished to do so, subject to
21 // the following conditions:
23 // The above copyright notice and this permission notice shall be
24 // included in all copies or substantial portions of the Software.
26 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
27 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
28 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
29 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
30 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
31 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
32 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
36 // Copyright (c) Microsoft. All rights reserved.
37 // Licensed under the MIT license. See LICENSE file in the project root for full license information.
40 // - mscorlib/system/valuetype.cs
43 using System.Reflection;
44 using System.Runtime.CompilerServices;
45 using System.Runtime.InteropServices;
46 using System.Threading;
52 public abstract class ValueType
55 * Caution: Fields added to ValueType can mess with sub class layouts.
56 * Causing bugs that appear completely unrelated as #30060
58 private static class Internal
60 public static int hash_code_of_ptr_seed = 0;
63 protected ValueType ()
67 [MethodImplAttribute (MethodImplOptions.InternalCall)]
68 private extern static bool InternalEquals (object o1, object o2, out object[] fields);
70 // This is also used by RuntimeHelpers
71 internal static bool DefaultEquals (object o1, object o2)
73 if (o1 == null && o2 == null)
75 if (o1 == null || o2 == null)
78 RuntimeType o1_type = (RuntimeType) o1.GetType ();
79 RuntimeType o2_type = (RuntimeType) o2.GetType ();
81 if (o1_type != o2_type)
85 bool res = InternalEquals (o1, o2, out fields);
89 for (int i = 0; i < fields.Length; i += 2) {
90 object meVal = fields [i];
91 object youVal = fields [i + 1];
99 if (!meVal.Equals (youVal))
107 // True if this instance and o represent the same type
108 // and have the same value.
110 public override bool Equals (object obj)
112 return DefaultEquals (this, obj);
115 [MethodImplAttribute (MethodImplOptions.InternalCall)]
116 internal extern static int InternalGetHashCode (object o, out object[] fields);
119 // Gets a hashcode for this value type using the
120 // bits in the structure
122 public override int GetHashCode ()
125 int result = InternalGetHashCode (this, out fields);
128 for (int i = 0; i < fields.Length; ++i)
129 if (fields [i] != null)
130 result ^= fields [i].GetHashCode ();
135 internal static int GetHashCodeOfPtr (IntPtr ptr)
137 int hash_code = (int) ptr;
138 int seed = Internal.hash_code_of_ptr_seed;
141 /* We use the first non-0 pointer as the seed, all hashcodes will be
142 * based off that. This is to make sure that we only reveal relative
143 * memory addresses and never absolute ones. */
145 Interlocked.CompareExchange (ref Internal.hash_code_of_ptr_seed, seed, 0);
146 seed = Internal.hash_code_of_ptr_seed;
149 return hash_code - seed;
153 // Stringified representation of this ValueType.
154 // Must be overriden for better results, by default
155 // it just returns the Type name.
157 public override string ToString ()
159 return GetType ().FullName;