Marshal.cs :  » 2.6.4-mono-.net-core » System.Runtime » System » Runtime » InteropServices » C# / CSharp Open Source

// System.Runtime.InteropServices.Marshal.cs
//
// Sean MacIsaac (macisaac@ximian.com)
// Paolo Molaro (lupus@ximian.com)
// Dietmar Maurer (dietmar@ximian.com)
// Jonathan Chambers (joncham@gmail.com)
//
// (C) 2001-2002 Ximian, Inc.

//
// Copyright (C) 2004 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
// "Software"), to deal in the Software without restriction, including
// without limitation the rights to use, copy, modify, merge, publish,
// distribute, sublicense, and/or sell copies of the Software, and to
// permit persons to whom the Software is furnished to do so, subject to
// the following conditions:
// 
// The above copyright notice and this permission notice shall be
// included in all copies or substantial portions of the Software.
// 
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
// NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
// LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
// OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
// WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
//

using System.Collections;
using System.Runtime.CompilerServices;
using System;
using System.Security;
using System.Reflection;
using System.Threading;

using System.Runtime.ConstrainedExecution;
#if !MOONLIGHT
using System.Runtime.InteropServices.ComTypes;
#endif

#if !MOONLIGHT
using Mono.Interop;
#endif

namespace System.Runtime.InteropServices{
  [SuppressUnmanagedCodeSecurity ()]
  public static class Marshal
  {
    /* fields */
    public static readonly int SystemMaxDBCSCharSize = 2; // don't know what this is
    public static readonly int SystemDefaultCharSize;

    static Marshal ()
    {
      SystemDefaultCharSize = Environment.OSVersion.Platform == PlatformID.Win32NT ? 2 : 1;
    }

    [MethodImplAttribute (MethodImplOptions.InternalCall)]
    private extern static int AddRefInternal (IntPtr pUnk);

    public static int AddRef (IntPtr pUnk)
    {
      if (pUnk == IntPtr.Zero)
        throw new ArgumentException ("Value cannot be null.", "pUnk");
      return AddRefInternal (pUnk);
    }

    [MethodImplAttribute(MethodImplOptions.InternalCall)]
    public extern static IntPtr AllocCoTaskMem (int cb);

    [MethodImplAttribute(MethodImplOptions.InternalCall)]
    [ReliabilityContractAttribute (Consistency.WillNotCorruptState, Cer.MayFail)]
    public extern static IntPtr AllocHGlobal (IntPtr cb);

    [ReliabilityContractAttribute (Consistency.WillNotCorruptState, Cer.MayFail)]
    public static IntPtr AllocHGlobal (int cb)
    {
      return AllocHGlobal ((IntPtr)cb);
    }

    [MonoTODO]
    public static object BindToMoniker (string monikerName)
    {
      throw new NotImplementedException ();
    }

    [MonoTODO]
    public static void ChangeWrapperHandleStrength (object otp, bool fIsWeak)
    {
      throw new NotImplementedException ();
    }

    [MethodImplAttribute(MethodImplOptions.InternalCall)]
    internal extern static void copy_to_unmanaged (Array source, int startIndex,
                     IntPtr destination, int length);

    [MethodImplAttribute(MethodImplOptions.InternalCall)]
    internal extern static void copy_from_unmanaged (IntPtr source, int startIndex,
                 Array destination, int length);

    public static void Copy (byte[] source, int startIndex, IntPtr destination, int length)
    {
      copy_to_unmanaged (source, startIndex, destination, length);
    }

    public static void Copy (char[] source, int startIndex, IntPtr destination, int length)
    {
      copy_to_unmanaged (source, startIndex, destination, length);
    }

    public static void Copy (short[] source, int startIndex, IntPtr destination, int length)
    {
      copy_to_unmanaged (source, startIndex, destination, length);
    }

    public static void Copy (int[] source, int startIndex, IntPtr destination, int length)
    {
      copy_to_unmanaged (source, startIndex, destination, length);
    }

    public static void Copy (long[] source, int startIndex, IntPtr destination, int length)
    {
      copy_to_unmanaged (source, startIndex, destination, length);
    }

    public static void Copy (float[] source, int startIndex, IntPtr destination, int length)
    {
      copy_to_unmanaged (source, startIndex, destination, length);
    }

    public static void Copy (double[] source, int startIndex, IntPtr destination, int length)
    {
      copy_to_unmanaged (source, startIndex, destination, length);
    }

    public static void Copy (IntPtr[] source, int startIndex, IntPtr destination, int length)
    {
      copy_to_unmanaged (source, startIndex, destination, length);
    }

    public static void Copy (IntPtr source, byte[] destination, int startIndex, int length)
    {
      copy_from_unmanaged (source, startIndex, destination, length);
    }

    public static void Copy (IntPtr source, char[] destination, int startIndex, int length)
    {
      copy_from_unmanaged (source, startIndex, destination, length);
    }

    public static void Copy (IntPtr source, short[] destination, int startIndex, int length)
    {
      copy_from_unmanaged (source, startIndex, destination, length);
    }

    public static void Copy (IntPtr source, int[] destination, int startIndex, int length)
    {
      copy_from_unmanaged (source, startIndex, destination, length);
    }

    public static void Copy (IntPtr source, long[] destination, int startIndex, int length)
    {
      copy_from_unmanaged (source, startIndex, destination, length);
    }

    public static void Copy (IntPtr source, float[] destination, int startIndex, int length)
    {
      copy_from_unmanaged (source, startIndex, destination, length);
    }

    public static void Copy (IntPtr source, double[] destination, int startIndex, int length)
    {
      copy_from_unmanaged (source, startIndex, destination, length);
    }

    public static void Copy (IntPtr source, IntPtr[] destination, int startIndex, int length)
    {
      copy_from_unmanaged (source, startIndex, destination, length);
    }

    public static IntPtr CreateAggregatedObject (IntPtr pOuter,
                   object o)
    {
      throw new NotImplementedException ();
    }

#if !MOONLIGHT
    public static object CreateWrapperOfType (object o, Type t)
    {
      __ComObject co = o as __ComObject;
      if (co == null)
        throw new ArgumentException ("o must derive from __ComObject", "o");
      if (t == null)
        throw new ArgumentNullException ("t");

      Type[] itfs = o.GetType ().GetInterfaces ();
      foreach (Type itf in itfs) {
        if (itf.IsImport && co.GetInterface (itf) == IntPtr.Zero)
          throw new InvalidCastException ();
      }

      return ComInteropProxy.GetProxy (co.IUnknown, t).GetTransparentProxy ();
    }
#endif

    [MethodImplAttribute(MethodImplOptions.InternalCall)]
    [ComVisible (true)]
    public extern static void DestroyStructure (IntPtr ptr, Type structuretype);

    [MethodImplAttribute(MethodImplOptions.InternalCall)]
    public extern static void FreeBSTR (IntPtr ptr);

    [MethodImplAttribute(MethodImplOptions.InternalCall)]
    public extern static void FreeCoTaskMem (IntPtr ptr);

    [MethodImplAttribute(MethodImplOptions.InternalCall)]
    [ReliabilityContractAttribute (Consistency.WillNotCorruptState, Cer.Success)]
    public extern static void FreeHGlobal (IntPtr hglobal);

    static void ClearBSTR (IntPtr ptr)
    {
      int len = ReadInt32 (ptr, -4);

      for (int i = 0; i < len; i++)
        WriteByte (ptr, i, 0);
    }
    
    public static void ZeroFreeBSTR (IntPtr s)
    {
      ClearBSTR (s);
      FreeBSTR (s);
    }

    static void ClearAnsi (IntPtr ptr)
    {
      for (int i = 0; ReadByte (ptr, i) != 0; i++)
        WriteByte (ptr, i, 0);
    }

    static void ClearUnicode (IntPtr ptr)
    {
      for (int i = 0; ReadInt16 (ptr, i) != 0; i += 2)
        WriteInt16 (ptr, i, 0);
    }
    
    public static void ZeroFreeCoTaskMemAnsi (IntPtr s)
    {
      ClearAnsi (s);
      FreeCoTaskMem (s);
    }

    public static void ZeroFreeCoTaskMemUnicode (IntPtr s)
    {
      ClearUnicode (s);
      FreeCoTaskMem (s);
    }

    public static void ZeroFreeGlobalAllocAnsi (IntPtr s)
    {
      ClearAnsi (s);
      FreeHGlobal (s);
    }

    public static void ZeroFreeGlobalAllocUnicode (IntPtr s)
    {
      ClearUnicode (s);
      FreeHGlobal (s);
    }

#if !MOONLIGHT
    public static Guid GenerateGuidForType (Type type)
    {
      return type.GUID;
    }

    [MonoTODO]
    public static string GenerateProgIdForType (Type type)
    {
      throw new NotImplementedException ();
    }

    [MonoTODO]
    public static object GetActiveObject (string progID)
    {
      throw new NotImplementedException ();
    }

    [MethodImplAttribute (MethodImplOptions.InternalCall)]
    private extern static IntPtr GetCCW (object o, Type T);

    private static IntPtr GetComInterfaceForObjectInternal (object o, Type T)
    {
      if (IsComObject (o))
        return ((__ComObject)o).GetInterface (T);
      else
        return GetCCW (o, T);
    }

    public static IntPtr GetComInterfaceForObject (object o, Type T)
    {
      IntPtr pItf = GetComInterfaceForObjectInternal (o, T);
      AddRef (pItf);
      return pItf;
    }

    [MonoTODO]
    public static IntPtr GetComInterfaceForObjectInContext (object o, Type t)
    {
      throw new NotImplementedException ();
    }

    [MonoNotSupportedAttribute ("MSDN states user code should never need to call this method.")]
    public static object GetComObjectData (object obj, object key)
    {
      throw new NotSupportedException ("MSDN states user code should never need to call this method.");
    }

    [MethodImplAttribute(MethodImplOptions.InternalCall)]
    private extern static int GetComSlotForMethodInfoInternal (MemberInfo m);

    public static int GetComSlotForMethodInfo (MemberInfo m)
    {
      if (m == null)
        throw new ArgumentNullException ("m");
      if (!(m is MethodInfo))
        throw new ArgumentException ("The MemberInfo must be an interface method.", "m");
      if (!m.DeclaringType.IsInterface)
        throw new ArgumentException ("The MemberInfo must be an interface method.", "m");
      return GetComSlotForMethodInfoInternal (m);
    }

    [MonoTODO]
    public static int GetEndComSlot (Type t)
    {
      throw new NotImplementedException ();
    }

    [MonoTODO]
    public static int GetExceptionCode()
    {
      throw new NotImplementedException ();
    }

    [MonoTODO]
    [ComVisible (true)]
    public static IntPtr GetExceptionPointers()
    {
      throw new NotImplementedException ();
    }

    public static IntPtr GetHINSTANCE (Module m)
    {
      if (m == null)
        throw new ArgumentNullException ("m");

      return m.GetHINSTANCE ();
    }
#endif // !NET_2_1

    [MonoTODO ("SetErrorInfo")]
    public static int GetHRForException (Exception e)
    {
      return e.hresult;
    }

    [MonoTODO]
    [ReliabilityContract (Consistency.WillNotCorruptState, Cer.Success)]
    public static int GetHRForLastWin32Error()
    {
      throw new NotImplementedException ();
    }
#if !MOONLIGHT
    [MethodImplAttribute (MethodImplOptions.InternalCall)]
    private extern static IntPtr GetIDispatchForObjectInternal (object o);

    public static IntPtr GetIDispatchForObject (object o)
    {
      IntPtr pUnk = GetIDispatchForObjectInternal (o);
      // Internal method does not AddRef
      AddRef (pUnk);
      return pUnk;
    }

    [MonoTODO]
    public static IntPtr GetIDispatchForObjectInContext (object o)
    {
      throw new NotImplementedException ();
    }

    [MonoTODO]
    public static IntPtr GetITypeInfoForType (Type t)
    {
      throw new NotImplementedException ();
    }

    [MethodImplAttribute (MethodImplOptions.InternalCall)]
    private extern static IntPtr GetIUnknownForObjectInternal (object o);

    public static IntPtr GetIUnknownForObject (object o)
    {
      IntPtr pUnk = GetIUnknownForObjectInternal (o);
      // Internal method does not AddRef
      AddRef (pUnk);
      return pUnk;
    }

    [MonoTODO]
    public static IntPtr GetIUnknownForObjectInContext (object o)
    {
      throw new NotImplementedException ();
    }

    [MonoTODO]
    [Obsolete ("This method has been deprecated")]
    public static IntPtr GetManagedThunkForUnmanagedMethodPtr (IntPtr pfnMethodToWrap, IntPtr pbSignature, int cbSignature)
    {
      throw new NotImplementedException ();
    }

    [MonoTODO]
    public static MemberInfo GetMethodInfoForComSlot (Type t, int slot, ref ComMemberType memberType)
    {
      throw new NotImplementedException ();
    }

    public static void GetNativeVariantForObject (object obj, IntPtr pDstNativeVariant)
    {
      Variant vt = new Variant();
      vt.SetValue(obj);
      Marshal.StructureToPtr(vt, pDstNativeVariant, false);
    }

    [MethodImplAttribute (MethodImplOptions.InternalCall)]
    private static extern object GetObjectForCCW (IntPtr pUnk);

    public static object GetObjectForIUnknown (IntPtr pUnk)
    {
      object obj = GetObjectForCCW (pUnk);
      // was not a CCW
      if (obj == null) {
        ComInteropProxy proxy = ComInteropProxy.GetProxy (pUnk, typeof (__ComObject));
        obj = proxy.GetTransparentProxy ();
      }
      return obj;
    }

    public static object GetObjectForNativeVariant (IntPtr pSrcNativeVariant)
    {
      Variant vt = (Variant)Marshal.PtrToStructure(pSrcNativeVariant, typeof(Variant));
      return vt.GetValue();
    }

    public static object[] GetObjectsForNativeVariants (IntPtr aSrcNativeVariant, int cVars)
    {
      if (cVars < 0)
        throw new ArgumentOutOfRangeException ("cVars", "cVars cannot be a negative number.");
      object[] objects = new object[cVars];
      for (int i = 0; i < cVars; i++)
        objects[i] = GetObjectForNativeVariant ((IntPtr)(aSrcNativeVariant.ToInt64 () +
          i * SizeOf (typeof(Variant))));
      return objects;
    }

    [MonoTODO]
    public static int GetStartComSlot (Type t)
    {
      throw new NotImplementedException ();
    }

    [MonoTODO]
    [Obsolete ("This method has been deprecated")]
    public static Thread GetThreadFromFiberCookie (int cookie)
    {
      throw new NotImplementedException ();
    }

    public static object GetTypedObjectForIUnknown (IntPtr pUnk, Type t)
    {
      ComInteropProxy proxy = new ComInteropProxy (pUnk, t);
      __ComObject co = (__ComObject)proxy.GetTransparentProxy ();
      foreach (Type itf in t.GetInterfaces ()) {
        if ((itf.Attributes & TypeAttributes.Import) == TypeAttributes.Import) {
          if (co.GetInterface (itf) == IntPtr.Zero)
            return null;
        }
      }
      return co;
    }

    [MonoTODO]
    public static Type GetTypeForITypeInfo (IntPtr piTypeInfo)
    {
      throw new NotImplementedException ();
    }

    [Obsolete]
    [MonoTODO]
    public static string GetTypeInfoName (UCOMITypeInfo pTI)
    {
      throw new NotImplementedException ();
    }

    public static string GetTypeInfoName (ITypeInfo typeInfo)
    {
      throw new NotImplementedException ();
    }

    [Obsolete]
    [MonoTODO]
    public static Guid GetTypeLibGuid (UCOMITypeLib pTLB)
    {
      throw new NotImplementedException ();
    }

    [MonoTODO]
    public static Guid GetTypeLibGuid (ITypeLib typelib)
    {
      throw new NotImplementedException ();
    }

    [MonoTODO]
    public static Guid GetTypeLibGuidForAssembly (Assembly asm)
    {
      throw new NotImplementedException ();
    }

    [Obsolete]
    [MonoTODO]
    public static int GetTypeLibLcid (UCOMITypeLib pTLB)
    {
      throw new NotImplementedException ();
    }

    [MonoTODO]
    public static int GetTypeLibLcid (ITypeLib typelib)
    {
      throw new NotImplementedException ();
    }

    [Obsolete]
    [MonoTODO]
    public static string GetTypeLibName (UCOMITypeLib pTLB)
    {
      throw new NotImplementedException ();
    }

    [MonoTODO]
    public static string GetTypeLibName (ITypeLib typelib)
    {
      throw new NotImplementedException ();
    }

    [MonoTODO]
    public static void GetTypeLibVersionForAssembly (Assembly inputAssembly, out int majorVersion, out int minorVersion)
    {
      throw new NotImplementedException ();
    }

    public static object GetUniqueObjectForIUnknown (IntPtr unknown)
    {
      throw new NotImplementedException ();
    }

    [MonoTODO]
    [Obsolete ("This method has been deprecated")]
    public static IntPtr GetUnmanagedThunkForManagedMethodPtr (IntPtr pfnMethodToWrap, IntPtr pbSignature, int cbSignature)
    {
      throw new NotImplementedException ();
    }

    [MethodImplAttribute (MethodImplOptions.InternalCall)]
    public extern static bool IsComObject (object o);

    [MonoTODO]
    public static bool IsTypeVisibleFromCom (Type t)
    {
      throw new NotImplementedException ();
    }

    [MonoTODO]
    public static int NumParamBytes (MethodInfo m)
    {
      throw new NotImplementedException ();
    }
#endif // !NET_2_1

    [MethodImplAttribute(MethodImplOptions.InternalCall)]
    [ReliabilityContractAttribute (Consistency.WillNotCorruptState, Cer.Success)]
    public static extern int GetLastWin32Error();

    [MethodImplAttribute(MethodImplOptions.InternalCall)]
    public extern static IntPtr OffsetOf (Type t, string fieldName);

    [MethodImplAttribute(MethodImplOptions.InternalCall)]
    public extern static void Prelink (MethodInfo m);

    [MethodImplAttribute(MethodImplOptions.InternalCall)]
    public extern static void PrelinkAll (Type c);

    [MethodImplAttribute(MethodImplOptions.InternalCall)]
    public extern static string PtrToStringAnsi (IntPtr ptr);
    
    [MethodImplAttribute(MethodImplOptions.InternalCall)]
    public extern static string PtrToStringAnsi (IntPtr ptr, int len);

    public static string PtrToStringAuto (IntPtr ptr)
    {
      return SystemDefaultCharSize == 2
        ? PtrToStringUni (ptr) : PtrToStringAnsi (ptr);
    }
    
    public static string PtrToStringAuto (IntPtr ptr, int len)
    {
      return SystemDefaultCharSize == 2
        ? PtrToStringUni (ptr, len) : PtrToStringAnsi (ptr, len);
    }

    [MethodImplAttribute(MethodImplOptions.InternalCall)]
    public extern static string PtrToStringUni (IntPtr ptr);

    [MethodImplAttribute(MethodImplOptions.InternalCall)]
    public extern static string PtrToStringUni (IntPtr ptr, int len);

    [MethodImplAttribute(MethodImplOptions.InternalCall)]
    public extern static string PtrToStringBSTR (IntPtr ptr);
    
    [MethodImplAttribute(MethodImplOptions.InternalCall)]
    [ComVisible (true)]
    public extern static void PtrToStructure (IntPtr ptr, object structure);

    [MethodImplAttribute(MethodImplOptions.InternalCall)]
    [ComVisible (true)]
    public extern static object PtrToStructure (IntPtr ptr, Type structureType);

    [MethodImplAttribute (MethodImplOptions.InternalCall)]
    private extern static int QueryInterfaceInternal (IntPtr pUnk, ref Guid iid, out IntPtr ppv);

    public static int QueryInterface (IntPtr pUnk, ref Guid iid, out IntPtr ppv)
    {
      if (pUnk == IntPtr.Zero)
        throw new ArgumentException ("Value cannot be null.", "pUnk");
      return QueryInterfaceInternal (pUnk, ref iid, out ppv);
    }

    public static byte ReadByte (IntPtr ptr)
    {
      return ReadByte (ptr, 0);
    }

    [MethodImplAttribute(MethodImplOptions.InternalCall)]
    public extern static byte ReadByte (IntPtr ptr, int ofs);

    [MonoTODO]
    public static byte ReadByte ([In, MarshalAs (UnmanagedType.AsAny)] object ptr, int ofs)
    {
      throw new NotImplementedException ();
    }

    public static short ReadInt16 (IntPtr ptr)
    {
      return ReadInt16 (ptr, 0);
    }

    [MethodImplAttribute(MethodImplOptions.InternalCall)]
    public extern static short ReadInt16 (IntPtr ptr, int ofs);

    [MonoTODO]
    public static short ReadInt16 ([In, MarshalAs(UnmanagedType.AsAny)] object ptr, int ofs)
    {
      throw new NotImplementedException ();
    }

    [ReliabilityContractAttribute (Consistency.WillNotCorruptState, Cer.Success)]
    public static int ReadInt32 (IntPtr ptr)
    {
      return ReadInt32 (ptr, 0);
    }

    [ReliabilityContractAttribute (Consistency.WillNotCorruptState, Cer.Success)]
    [MethodImplAttribute(MethodImplOptions.InternalCall)]
    public extern static int ReadInt32 (IntPtr ptr, int ofs);

    [ReliabilityContractAttribute (Consistency.WillNotCorruptState, Cer.Success)]
    [MonoTODO]
    public static int ReadInt32 ([In, MarshalAs(UnmanagedType.AsAny)] object ptr, int ofs)
    {
      throw new NotImplementedException ();
    }

    [ReliabilityContractAttribute (Consistency.WillNotCorruptState, Cer.Success)]
    public static long ReadInt64 (IntPtr ptr)
    {
      return ReadInt64 (ptr, 0);
    }

    [ReliabilityContractAttribute (Consistency.WillNotCorruptState, Cer.Success)]
    [MethodImplAttribute(MethodImplOptions.InternalCall)]
    public extern static long ReadInt64 (IntPtr ptr, int ofs);

    [ReliabilityContractAttribute (Consistency.WillNotCorruptState, Cer.Success)]
    [MonoTODO]
    public static long ReadInt64 ([In, MarshalAs (UnmanagedType.AsAny)] object ptr, int ofs)
    {
      throw new NotImplementedException ();
    }

    [ReliabilityContractAttribute (Consistency.WillNotCorruptState, Cer.Success)]
    public static IntPtr ReadIntPtr (IntPtr ptr)
    {
      return ReadIntPtr (ptr, 0);
    }
    
    [ReliabilityContractAttribute (Consistency.WillNotCorruptState, Cer.Success)]
    [MethodImplAttribute(MethodImplOptions.InternalCall)]
    public extern static IntPtr ReadIntPtr (IntPtr ptr, int ofs);

    [ReliabilityContractAttribute (Consistency.WillNotCorruptState, Cer.Success)]
    [MonoTODO]
    public static IntPtr ReadIntPtr ([In, MarshalAs (UnmanagedType.AsAny)] object ptr, int ofs)
    {
      throw new NotImplementedException ();
    }

    [MethodImplAttribute (MethodImplOptions.InternalCall)]
    public extern static IntPtr ReAllocCoTaskMem (IntPtr pv, int cb);

    [MethodImplAttribute(MethodImplOptions.InternalCall)]
    public extern static IntPtr ReAllocHGlobal (IntPtr pv, IntPtr cb);

    [ReliabilityContractAttribute (Consistency.WillNotCorruptState, Cer.Success)]
    [MethodImplAttribute (MethodImplOptions.InternalCall)]
    private extern static int ReleaseInternal (IntPtr pUnk);

    [ReliabilityContract (Consistency.WillNotCorruptState, Cer.Success)]
    public static int Release (IntPtr pUnk)
    {
      if (pUnk == IntPtr.Zero)
        throw new ArgumentException ("Value cannot be null.", "pUnk");
      return ReleaseInternal (pUnk);
    }

#if !MOONLIGHT
    [MethodImplAttribute (MethodImplOptions.InternalCall)]
    private extern static int ReleaseComObjectInternal (object co);

    public static int ReleaseComObject (object o)
    {
      if (o == null)
        throw new ArgumentException ("Value cannot be null.", "o");
      if (!IsComObject (o))
        throw new ArgumentException ("Value must be a Com object.", "o");
      return ReleaseComObjectInternal (o);
    }

    [Obsolete]
    [MonoTODO]
    public static void ReleaseThreadCache()
    {
      throw new NotImplementedException ();
    }

    [MonoNotSupportedAttribute ("MSDN states user code should never need to call this method.")]
    public static bool SetComObjectData (object obj, object key, object data)
    {
      throw new NotSupportedException ("MSDN states user code should never need to call this method.");
    }
#endif // !NET_2_1

    [ComVisible (true)]
    public static int SizeOf (object structure)
    {
      return SizeOf (structure.GetType ());
    }

    [MethodImplAttribute(MethodImplOptions.InternalCall)]
    public extern static int SizeOf (Type t);

    [MethodImplAttribute(MethodImplOptions.InternalCall)]
    public extern static IntPtr StringToBSTR (string s);

    //
    // I believe this is wrong, because in Mono and in P/Invoke
    // we treat "Ansi" conversions as UTF-8 conversions, while
    // this one does not do this
    //
    public static IntPtr StringToCoTaskMemAnsi (string s)
    {
      int length = s.Length + 1;
      IntPtr ctm = AllocCoTaskMem (length);

      byte[] asBytes = new byte[length];
      for (int i = 0; i < s.Length; i++)
        asBytes[i] = (byte)s[i];
      asBytes[s.Length] = 0;

      copy_to_unmanaged (asBytes, 0, ctm, length);
      return ctm;
    }

    public static IntPtr StringToCoTaskMemAuto (string s)
    {
      return SystemDefaultCharSize == 2
        ? StringToCoTaskMemUni (s) : StringToCoTaskMemAnsi (s);
    }

    public static IntPtr StringToCoTaskMemUni (string s)
    {
      int length = s.Length + 1;
      IntPtr ctm = AllocCoTaskMem (length * 2);
      
      char[] asChars = new char[length];
      s.CopyTo (0, asChars, 0, s.Length);
      asChars[s.Length] = '\0';

      copy_to_unmanaged (asChars, 0, ctm, length);
      return ctm;
    }

    [MethodImplAttribute(MethodImplOptions.InternalCall)]
    public extern static IntPtr StringToHGlobalAnsi (string s);

    public static IntPtr StringToHGlobalAuto (string s)
    {
      return SystemDefaultCharSize == 2
        ? StringToHGlobalUni (s) : StringToHGlobalAnsi (s);
    }

    [MethodImplAttribute(MethodImplOptions.InternalCall)]
    public extern static IntPtr StringToHGlobalUni (string s);

#if !MOONLIGHT
    public static IntPtr SecureStringToBSTR (SecureString s)
    {
      if (s == null)
        throw new ArgumentNullException ("s");
      int len = s.Length;
      IntPtr ctm = AllocCoTaskMem ((len+1) * 2 + 4);
      byte [] buffer = null;
      WriteInt32 (ctm, 0, len*2);
      try {
        buffer = s.GetBuffer ();

        for (int i = 0; i < len; i++)
          WriteInt16 (ctm, 4 + (i * 2), (short) ((buffer [(i*2)] << 8) | (buffer [i*2+1])));
        WriteInt16 (ctm, 4 + buffer.Length, 0);
      } finally {
        if (buffer != null)
          for (int i = buffer.Length; i > 0; ){
            i--;
            buffer [i] = 0;
          }
      }
      return (IntPtr) ((long)ctm + 4);
    }

    public static IntPtr SecureStringToCoTaskMemAnsi (SecureString s)
    {
      if (s == null)
        throw new ArgumentNullException ("s");
      int len = s.Length;
      IntPtr ctm = AllocCoTaskMem (len + 1);
      byte [] copy = new byte [len+1];

      try {
        byte [] buffer = s.GetBuffer ();
        int i = 0, j = 0;
        for (; i < len; i++, j += 2){
          copy [i] = buffer [j+1];
          buffer [j] = 0;
          buffer [j+1] = 0;
        }
        copy [i] = 0;
        copy_to_unmanaged (copy, 0, ctm, len+1);
      } finally {
        // Ensure that we clear the buffer.
        for (int i = len; i > 0; ){
          i--;
          copy [i] = 0;
        }
      }
      return ctm;
    }

    public static IntPtr SecureStringToCoTaskMemUnicode (SecureString s)
    {
      if (s == null)
        throw new ArgumentNullException ("s");
      int len = s.Length;
      IntPtr ctm = AllocCoTaskMem (len * 2 + 2);
      byte [] buffer = null;
      try {
        buffer = s.GetBuffer ();
        for (int i = 0; i < len; i++)
          WriteInt16 (ctm, i * 2, (short) ((buffer [(i*2)] << 8) | (buffer [i*2+1])));
        WriteInt16 (ctm, buffer.Length, 0);
      } finally {
        if (buffer != null)
          for (int i = buffer.Length; i > 0; ){
            i--;
            buffer [i] = 0;
          }
      }
      return ctm;
    }

    public static IntPtr SecureStringToGlobalAllocAnsi (SecureString s)
    {
      if (s == null)
        throw new ArgumentNullException ("s");
      return SecureStringToCoTaskMemAnsi (s);
    }

    public static IntPtr SecureStringToGlobalAllocUnicode (SecureString s)
    {
      if (s == null)
        throw new ArgumentNullException ("s");
      return SecureStringToCoTaskMemUnicode (s);
    }
#endif

    [ReliabilityContractAttribute (Consistency.WillNotCorruptState, Cer.MayFail)]
    [ComVisible (true)]
    [MethodImplAttribute(MethodImplOptions.InternalCall)]
    public extern static void StructureToPtr (object structure, IntPtr ptr, bool fDeleteOld);

    public static void ThrowExceptionForHR (int errorCode) {
      Exception ex = GetExceptionForHR (errorCode);
      if (ex != null)
        throw ex;
    }

    public static void ThrowExceptionForHR (int errorCode, IntPtr errorInfo) {
      Exception ex = GetExceptionForHR (errorCode, errorInfo);
      if (ex != null)
        throw ex;
    }

    [MethodImplAttribute(MethodImplOptions.InternalCall)]
    public extern static IntPtr UnsafeAddrOfPinnedArrayElement (Array arr, int index);

    public static void WriteByte (IntPtr ptr, byte val)
    {
      WriteByte (ptr, 0, val);
    }

    [MethodImplAttribute(MethodImplOptions.InternalCall)]
    public extern static void WriteByte (IntPtr ptr, int ofs, byte val);

    [MonoTODO]
    public static void WriteByte ([In, Out, MarshalAs (UnmanagedType.AsAny)] object ptr, int ofs, byte val)
    {
      throw new NotImplementedException ();
    }

    public static void WriteInt16 (IntPtr ptr, short val)
    {
      WriteInt16 (ptr, 0, val);
    }

    [MethodImplAttribute(MethodImplOptions.InternalCall)]
    public extern static void WriteInt16 (IntPtr ptr, int ofs, short val);

    [MonoTODO]
    public static void WriteInt16 ([In, Out, MarshalAs (UnmanagedType.AsAny)] object ptr, int ofs, short val)
    {
      throw new NotImplementedException ();
    }

    public static void WriteInt16 (IntPtr ptr, char val)
    {
      WriteInt16 (ptr, 0, val);
    }

    [MonoTODO]
    [MethodImplAttribute(MethodImplOptions.InternalCall)]
    public extern static void WriteInt16 (IntPtr ptr, int ofs, char val);

    [MonoTODO]
    public static void WriteInt16([In, Out] object ptr, int ofs, char val)
    {
      throw new NotImplementedException ();
    }

    public static void WriteInt32 (IntPtr ptr, int val)
    {
      WriteInt32 (ptr, 0, val);
    }

    [MethodImplAttribute(MethodImplOptions.InternalCall)]
    public extern static void WriteInt32 (IntPtr ptr, int ofs, int val);

    [MonoTODO]
    public static void WriteInt32([In, Out, MarshalAs(UnmanagedType.AsAny)] object ptr, int ofs, int val)
    {
      throw new NotImplementedException ();
    }

    public static void WriteInt64 (IntPtr ptr, long val)
    {
      WriteInt64 (ptr, 0, val);
    }

    [MethodImplAttribute(MethodImplOptions.InternalCall)]
    public extern static void WriteInt64 (IntPtr ptr, int ofs, long val);

    [MonoTODO]
    public static void WriteInt64 ([In, Out, MarshalAs (UnmanagedType.AsAny)] object ptr, int ofs, long val)
    {
      throw new NotImplementedException ();
    }

    public static void WriteIntPtr (IntPtr ptr, IntPtr val)
    {
      WriteIntPtr (ptr, 0, val);
    }

    [MethodImplAttribute(MethodImplOptions.InternalCall)]
    public extern static void WriteIntPtr (IntPtr ptr, int ofs, IntPtr val);

    [MonoTODO]
    public static void WriteIntPtr([In, Out, MarshalAs(UnmanagedType.AsAny)] object ptr, int ofs, IntPtr val)
    {
      throw new NotImplementedException ();
    }

    public static Exception GetExceptionForHR (int errorCode) {
      return GetExceptionForHR (errorCode, IntPtr.Zero);
    }

    public static Exception GetExceptionForHR (int errorCode, IntPtr errorInfo) {

      const int E_OUTOFMEMORY = unchecked ((int)0x8007000EL);
      const int E_INVALIDARG = unchecked ((int)0X80070057);
      
      switch (errorCode)
      {
      case E_OUTOFMEMORY:
        return new OutOfMemoryException ();
      case E_INVALIDARG:
        return new ArgumentException ();
      }
      if (errorCode < 0)
        return new COMException ("", errorCode);
      return null;
    }

#if !MOONLIGHT
    public static int FinalReleaseComObject (object o)
    {
      while (ReleaseComObject (o) != 0);
      return 0;
    }
#endif

    [MethodImplAttribute(MethodImplOptions.InternalCall)]
    private static extern Delegate GetDelegateForFunctionPointerInternal (IntPtr ptr, Type t);

    public static Delegate GetDelegateForFunctionPointer (IntPtr ptr, Type t)
    {
      if (t == null)
        throw new ArgumentNullException ("t");
      if (!t.IsSubclassOf (typeof (MulticastDelegate)) || (t == typeof (MulticastDelegate)))
        throw new ArgumentException ("Type is not a delegate", "t");
      if (ptr == IntPtr.Zero)
        throw new ArgumentNullException ("ptr");

      return GetDelegateForFunctionPointerInternal (ptr, t);
    }

    [MethodImplAttribute(MethodImplOptions.InternalCall)]
    private static extern IntPtr GetFunctionPointerForDelegateInternal (Delegate d);
    
    public static IntPtr GetFunctionPointerForDelegate (Delegate d)
    {
      if (d == null)
        throw new ArgumentNullException ("d");
      
      return GetFunctionPointerForDelegateInternal (d);
    }
  }
}