X-Git-Url: http://wien.tomnetworks.com/gitweb/?a=blobdiff_plain;f=mcs%2Fclass%2Fcorlib%2FSystem%2FValueType.cs;h=2956ffb317c034e67c8d92aec692adaedf53afd2;hb=f03a1b538bfb0d9be810688e8713731e122320b5;hp=641d18013de2c7cca33efc5720bb73e1516cd8a2;hpb=dbf19eb41dbd299c4c33d4de35ffe3cf6c669832;p=mono.git

diff --git a/mcs/class/corlib/System/ValueType.cs b/mcs/class/corlib/System/ValueType.cs
index 641d18013de..2956ffb317c 100644
--- a/mcs/class/corlib/System/ValueType.cs
+++ b/mcs/class/corlib/System/ValueType.cs
@@ -32,29 +32,56 @@
 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 //
 
+//
+// Copyright (c) Microsoft. All rights reserved.
+// Licensed under the MIT license. See LICENSE file in the project root for full license information.
+//
+// Files:
+//  - mscorlib/system/valuetype.cs
+//
+
 using System.Reflection;
 using System.Runtime.CompilerServices;
+using System.Runtime.InteropServices;
+using System.Threading;
 
 namespace System
 {
 	[Serializable]
+	[ComVisible (true)]
 	public abstract class ValueType
 	{
+		/*
+		 * Caution: Fields added to ValueType can mess with sub class layouts.
+		 * Causing bugs that appear completely unrelated as #30060
+		 */
+		private static class Internal
+		{
+			public static int hash_code_of_ptr_seed = 0;
+		}
+
 		protected ValueType ()
 		{
 		}
 
 		[MethodImplAttribute (MethodImplOptions.InternalCall)]
-		internal extern static bool InternalEquals (object o1, object o2, out object[] fields);
+		private extern static bool InternalEquals (object o1, object o2, out object[] fields);
 
 		// This is also used by RuntimeHelpers
 		internal static bool DefaultEquals (object o1, object o2)
 		{
-			object[] fields;
+			if (o1 == null && o2 == null)
+				return true;
+			if (o1 == null || o2 == null)
+				return false;
 
-			if (o2 == null)
+			RuntimeType o1_type = (RuntimeType) o1.GetType ();
+			RuntimeType o2_type = (RuntimeType) o2.GetType ();
+
+			if (o1_type != o2_type)
 				return false;
 
+			object[] fields;
 			bool res = InternalEquals (o1, o2, out fields);
 			if (fields == null)
 				return res;
@@ -80,8 +107,9 @@ namespace System
 		//   True if this instance and o represent the same type
 		//   and have the same value.
 		// </summary>
-		public override bool Equals (object o) {
-			return DefaultEquals (this, o);
+		public override bool Equals (object obj)
+		{
+			return DefaultEquals (this, obj);
 		}
 
 		[MethodImplAttribute (MethodImplOptions.InternalCall)]
@@ -104,6 +132,23 @@ namespace System
 			return result;
 		}
 
+		internal static int GetHashCodeOfPtr (IntPtr ptr)
+		{
+			int hash_code = (int) ptr;
+			int seed = Internal.hash_code_of_ptr_seed;
+
+			if (seed == 0) {
+				/* We use the first non-0 pointer as the seed, all hashcodes will be
+				 * based off that. This is to make sure that we only reveal relative
+				 * memory addresses and never absolute ones. */
+				seed = hash_code;
+				Interlocked.CompareExchange (ref Internal.hash_code_of_ptr_seed, seed, 0);
+				seed = Internal.hash_code_of_ptr_seed;
+			}
+
+			return hash_code - seed;
+		}
+
 		// <summary>
 		//   Stringified representation of this ValueType.
 		//   Must be overriden for better results, by default