X-Git-Url: http://wien.tomnetworks.com/gitweb/?a=blobdiff_plain;f=mcs%2Fclass%2Fcorlib%2FSystem.Runtime.InteropServices%2FGCHandle.cs;h=ec83a3e0756b6f79737d2acb38b87f4ea11ba02b;hb=2eb33cebf5d9669671d3023535456e9c9cf084f7;hp=67218468375d7caea990078900c470a6bdc7d22a;hpb=987f8c63e214937c50dcb308149f7558a2cbba41;p=mono.git

diff --git a/mcs/class/corlib/System.Runtime.InteropServices/GCHandle.cs b/mcs/class/corlib/System.Runtime.InteropServices/GCHandle.cs
index 67218468375..ec83a3e0756 100644
--- a/mcs/class/corlib/System.Runtime.InteropServices/GCHandle.cs
+++ b/mcs/class/corlib/System.Runtime.InteropServices/GCHandle.cs
@@ -7,7 +7,7 @@
 //
 
 //
-// Copyright (C) 2004 Novell, Inc (http://www.novell.com)
+// Copyright (C) 2004, 2009 Novell, Inc (http://www.novell.com)
 //
 // Permission is hereby granted, free of charge, to any person obtaining
 // a copy of this software and associated documentation files (the
@@ -30,15 +30,14 @@
 //
 
 using System;
+using System.Threading;
 using System.Runtime.CompilerServices;
 using System.Runtime.InteropServices;
 
 namespace System.Runtime.InteropServices
 {
 
-#if NET_2_0
 	[ComVisible(true)]
-#endif
 	[MonoTODO("Struct should be [StructLayout(LayoutKind.Sequential)] but will need to be reordered for that.")]
 	public struct GCHandle 
 	{
@@ -55,8 +54,11 @@ namespace System.Runtime.InteropServices
 			: this(obj, GCHandleType.Normal)
 		{}
 
-		private GCHandle(object value, GCHandleType type)
+		internal GCHandle(object value, GCHandleType type)
 		{
+			// MS does not crash/throw on (most) invalid GCHandleType values (except -1)
+			if ((type < GCHandleType.Weak) || (type > GCHandleType.Pinned))
+				type = GCHandleType.Normal;
 			handle = GetTargetHandle (value, 0, type);
 		}
 
@@ -74,6 +76,8 @@ namespace System.Runtime.InteropServices
 		{ 
 			get
 			{
+				if (!IsAllocated)
+					throw new InvalidOperationException (Locale.GetText ("Handle is not allocated"));
 				return GetTarget (handle);
 			} 
 			set
@@ -86,10 +90,10 @@ namespace System.Runtime.InteropServices
 		public IntPtr AddrOfPinnedObject()
 		{
 			IntPtr res = GetAddrOfPinnedObject(handle);
-			if (res == IntPtr.Zero)
-				throw new InvalidOperationException("The handle is not of Pinned type");
 			if (res == (IntPtr)(-1))
 				throw new ArgumentException ("Object contains non-primitive or non-blittable data.");
+			if (res == (IntPtr)(-2))
+				throw new InvalidOperationException("Handle is not pinned.");
 			return res;
 		}
 
@@ -105,8 +109,17 @@ namespace System.Runtime.InteropServices
 
 		public void Free()
 		{
-			FreeHandle(handle);
-			handle = 0;
+			// Copy the handle instance member to a local variable. This is required to prevent
+			// race conditions releasing the handle.
+			int local_handle = handle;
+
+			// Free the handle if it hasn't already been freed.
+			if (local_handle != 0 && Interlocked.CompareExchange (ref handle, 0, local_handle) == local_handle) {
+				FreeHandle (local_handle);
+			}
+			else {
+				throw new InvalidOperationException ("Handle is not initialized.");
+			}
 		}
 		
 		public static explicit operator IntPtr (GCHandle value)
@@ -117,7 +130,7 @@ namespace System.Runtime.InteropServices
 		public static explicit operator GCHandle(IntPtr value)
 		{
 			if (value == IntPtr.Zero)
-				throw new ArgumentException ("GCHandle value cannot be zero");
+				throw new InvalidOperationException ("GCHandle value cannot be zero");
 			if (!CheckCurrentDomain ((int)value))
 				throw new ArgumentException ("GCHandle value belongs to a different domain");
 			return new GCHandle (value);
@@ -138,23 +151,19 @@ namespace System.Runtime.InteropServices
 		[MethodImplAttribute(MethodImplOptions.InternalCall)]
 		private extern static IntPtr GetAddrOfPinnedObject(int handle);
 
-#if NET_2_0
 		public static bool operator ==(GCHandle a, GCHandle b)
 		{
-			return a.Equals(b);
+			return a.handle == b.handle;
 		}
 
 		public static bool operator !=(GCHandle a, GCHandle b)
 		{
-			return (!(a.Equals(b)));
+			return !(a == b);
 		}
 		
 		public override bool Equals(object o)
 		{
-			if (o == null || !(o is GCHandle))
-				return false;
-
-			return (handle == ((GCHandle)o).handle);
+			return o is GCHandle ? this == (GCHandle)o : false;
 		}
 
 		public override int GetHashCode()
@@ -171,7 +180,6 @@ namespace System.Runtime.InteropServices
 		{
 			return (IntPtr)value;
 		}
-#endif
 	} 
 }