2 // System.Runtime.InteropServices/GCHandle.cs
5 // Ajay kumar Dwivedi (adwiv@yahoo.com) ??
6 // Paolo Molaro (lupus@ximian.com)
10 // Copyright (C) 2004, 2009 Novell, Inc (http://www.novell.com)
12 // Permission is hereby granted, free of charge, to any person obtaining
13 // a copy of this software and associated documentation files (the
14 // "Software"), to deal in the Software without restriction, including
15 // without limitation the rights to use, copy, modify, merge, publish,
16 // distribute, sublicense, and/or sell copies of the Software, and to
17 // permit persons to whom the Software is furnished to do so, subject to
18 // the following conditions:
20 // The above copyright notice and this permission notice shall be
21 // included in all copies or substantial portions of the Software.
23 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
24 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
25 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
26 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
27 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
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29 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
33 using System.Runtime.CompilerServices;
34 using System.Runtime.InteropServices;
36 namespace System.Runtime.InteropServices
40 [MonoTODO("Struct should be [StructLayout(LayoutKind.Sequential)] but will need to be reordered for that.")]
41 public struct GCHandle
46 private GCHandle(IntPtr h)
52 private GCHandle(object obj)
53 : this(obj, GCHandleType.Normal)
56 internal GCHandle(object value, GCHandleType type)
58 // MS does not crash/throw on (most) invalid GCHandleType values (except -1)
59 if ((type < GCHandleType.Weak) || (type > GCHandleType.Pinned))
60 type = GCHandleType.Normal;
61 handle = GetTargetHandle (value, 0, type);
66 public bool IsAllocated
79 throw new InvalidOperationException (Locale.GetText ("Handle is not allocated"));
80 return GetTarget (handle);
84 handle = GetTargetHandle (value, handle, (GCHandleType)(-1));
89 public IntPtr AddrOfPinnedObject()
91 IntPtr res = GetAddrOfPinnedObject(handle);
92 if (res == (IntPtr)(-1))
93 throw new ArgumentException ("Object contains non-primitive or non-blittable data.");
94 if (res == (IntPtr)(-2))
95 throw new InvalidOperationException("Handle is not pinned.");
99 public static System.Runtime.InteropServices.GCHandle Alloc(object value)
101 return new GCHandle (value);
104 public static System.Runtime.InteropServices.GCHandle Alloc(object value, GCHandleType type)
106 return new GCHandle (value,type);
115 public static explicit operator IntPtr (GCHandle value)
117 return (IntPtr) value.handle;
120 public static explicit operator GCHandle(IntPtr value)
122 if (value == IntPtr.Zero)
123 throw new ArgumentException ("GCHandle value cannot be zero");
124 if (!CheckCurrentDomain ((int)value))
125 throw new ArgumentException ("GCHandle value belongs to a different domain");
126 return new GCHandle (value);
129 [MethodImplAttribute(MethodImplOptions.InternalCall)]
130 private extern static bool CheckCurrentDomain (int handle);
132 [MethodImplAttribute(MethodImplOptions.InternalCall)]
133 private extern static object GetTarget(int handle);
135 [MethodImplAttribute(MethodImplOptions.InternalCall)]
136 private extern static int GetTargetHandle(object obj, int handle, GCHandleType type);
138 [MethodImplAttribute(MethodImplOptions.InternalCall)]
139 private extern static void FreeHandle(int handle);
141 [MethodImplAttribute(MethodImplOptions.InternalCall)]
142 private extern static IntPtr GetAddrOfPinnedObject(int handle);
144 public static bool operator ==(GCHandle a, GCHandle b)
146 return a.handle == b.handle;
149 public static bool operator !=(GCHandle a, GCHandle b)
154 public override bool Equals(object o)
156 return o is GCHandle ? this == (GCHandle)o : false;
159 public override int GetHashCode()
161 return handle.GetHashCode ();
164 public static GCHandle FromIntPtr (IntPtr value)
166 return (GCHandle)value;
169 public static IntPtr ToIntPtr (GCHandle value)
171 return (IntPtr)value;