mcs/class/corlib/System/__ComObject.cs

   1 //
   2 // System.__ComObject
   3 //
   4 // Authors:
   5 //   Sebastien Pouliot <sebastien@ximian.com>
   6 //   Kornél Pál <http://www.kornelpal.hu/>
   7 //   Jonathan Chambers <joncham@gmail.com>
   8 //
   9 // Copyright (C) 2004 Novell (http://www.novell.com)
  10 // Copyright (C) 2005 Kornél Pál
  11 // Copyright (C) 2006 Jonathan Chambers
  12 //
  13
  14 //
  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:
  22 //
  23 // The above copyright notice and this permission notice shall be
  24 // included in all copies or substantial portions of the Software.
  25 //
  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.
  33 //
  34
  35 #if !FULL_AOT_RUNTIME
  36 using Mono.Interop;
  37 using System.Collections;
  38 using System.Runtime.InteropServices;
  39 using System.Runtime.CompilerServices;
  40 using System.Threading;
  41
  42 namespace System
  43 {
  44         // This is a private class that is used as a generic wrapper class
  45         // for COM objects that have no specific wrapper class.
  46         //
  47         // It has no public methods, it's functionality is exposed trough
  48         // System.Runtime.InteropServices.Marshal class and can be casted to
  49         // any interface that is implemented by the wrapped COM object.
  50         //
  51         // This class is referenced in .NET Framework SDK Documentation so
  52         // many times that obj.GetType().FullName == "System.__ComObject" and
  53         // Type.GetType("System.__ComObject") may be used.
  54
  55         [StructLayout (LayoutKind.Sequential)]
  56         internal class __ComObject : MarshalByRefObject
  57         {
  58 #pragma warning disable 169
  59                 #region Sync with object-internals.h
  60                 IntPtr iunknown;
  61                 IntPtr hash_table;
  62                 SynchronizationContext synchronization_context;
  63                 #endregion
  64 #pragma warning restore 169
  65
  66                 [MethodImplAttribute (MethodImplOptions.InternalCall)]
  67                 internal static extern __ComObject CreateRCW (Type t);
  68
  69                 [MethodImplAttribute (MethodImplOptions.InternalCall)]
  70                 private extern void ReleaseInterfaces ();
  71
  72                 ~__ComObject ()
  73                 {
  74                         if (synchronization_context != null)
  75                                 synchronization_context.Post ((state) => ReleaseInterfaces (), this);
  76                         else
  77                                 ReleaseInterfaces ();
  78                 }
  79
  80                 public __ComObject ()
  81                 {
  82                         Initialize (GetType ());
  83                 }
  84
  85                 internal __ComObject (Type t) {
  86                         Initialize (t);
  87                 }
  88
  89                 internal __ComObject (IntPtr pItf)
  90                 {
  91                         InitializeApartmentDetails ();
  92                         Guid iid = IID_IUnknown;
  93                         int hr = Marshal.QueryInterface (pItf, ref iid, out iunknown);
  94                         Marshal.ThrowExceptionForHR (hr);
  95                 }
  96
  97                 internal void Initialize (Type t)
  98                 {
  99                         InitializeApartmentDetails ();
 100                         // Guard multiple invocation.
 101                         if (iunknown != IntPtr.Zero)
 102                                 return;
 103
 104                         System.Runtime.CompilerServices.RuntimeHelpers.RunClassConstructor (t.TypeHandle);
 105
 106                         ObjectCreationDelegate ocd = ExtensibleClassFactory.GetObjectCreationCallback (t);
 107                         if (ocd != null) {
 108                                 iunknown = ocd (IntPtr.Zero);
 109                                 if (iunknown == IntPtr.Zero)
 110                                         throw new COMException (string.Format("ObjectCreationDelegate for type {0} failed to return a valid COM object", t));
 111                         }
 112                         else {
 113                                 int hr = CoCreateInstance (GetCLSID (t), IntPtr.Zero, 0x1 | 0x4 | 0x10, IID_IUnknown, out iunknown);
 114                                 Marshal.ThrowExceptionForHR (hr);
 115                         }
 116                 }
 117
 118                 private void InitializeApartmentDetails ()
 119                 {
 120                         // Only synchronization_context if thread is STA.
 121                         if (Thread.CurrentThread.GetApartmentState() != ApartmentState.STA)
 122                                 return;
 123
 124                         synchronization_context = SynchronizationContext.Current;
 125
 126                         // Check whether the current context is a plain SynchronizationContext object
 127                         // and handle this as if no context was set at all.
 128                         if (synchronization_context != null &&
 129                                 synchronization_context.GetType () == typeof(SynchronizationContext))
 130                                 synchronization_context = null;
 131                 }
 132
 133                 private static Guid GetCLSID (Type t)
 134                 {
 135                         if (t.IsImport)
 136                                 return t.GUID;
 137
 138                         // look at supertypes
 139                         Type super = t.BaseType;
 140                         while (super != typeof (object)) {
 141                                 if (super.IsImport)
 142                                         return super.GUID;
 143                                 super = super.BaseType;
 144                         }
 145                         throw new COMException ("Could not find base COM type for type " + t.ToString());
 146                 }
 147
 148                 [MethodImplAttribute (MethodImplOptions.InternalCall)]
 149                 internal extern IntPtr GetInterfaceInternal (Type t, bool throwException);
 150
 151                 internal IntPtr GetInterface (Type t, bool throwException) {
 152                         CheckIUnknown ();
 153                         return GetInterfaceInternal (t, throwException);
 154                 }
 155
 156                 internal IntPtr GetInterface(Type t)
 157                 {
 158                         return GetInterface (t, true);
 159                 }
 160
 161                 private void CheckIUnknown ()
 162                 {
 163                         if (iunknown == IntPtr.Zero)
 164                                 throw new InvalidComObjectException ("COM object that has been separated from its underlying RCW cannot be used.");
 165                 }
 166
 167                 internal IntPtr IUnknown
 168                 {
 169                         get
 170                         {
 171                                 if (iunknown == IntPtr.Zero)
 172                                         throw new InvalidComObjectException ("COM object that has been separated from its underlying RCW cannot be used.");
 173                                 return iunknown;
 174                         }
 175                 }
 176
 177                 internal IntPtr IDispatch
 178                 {
 179                         get
 180                         {
 181                                 IntPtr pUnk = GetInterface (typeof (IDispatch));
 182                                 if (pUnk == IntPtr.Zero)
 183                                         throw new InvalidComObjectException ("COM object that has been separated from its underlying RCW cannot be used.");
 184                                 return pUnk;
 185                         }
 186                 }
 187
 188                 internal static Guid IID_IUnknown
 189                 {
 190                         get
 191                         {
 192                                 return new Guid("00000000-0000-0000-C000-000000000046");
 193                         }
 194                 }
 195
 196                 internal static Guid IID_IDispatch
 197                 {
 198                         get
 199                         {
 200                                 return new Guid ("00020400-0000-0000-C000-000000000046");
 201                         }
 202                 }
 203
 204                 public override bool Equals (object obj)
 205                 {
 206                         CheckIUnknown ();
 207                         if (obj == null)
 208                                 return false;
 209
 210                         __ComObject co = obj as __ComObject;
 211                         if ((object)co == null)
 212                                 return false;
 213                         return (iunknown == co.IUnknown);
 214                 }
 215
 216                 public override int GetHashCode ()
 217                 {
 218                         CheckIUnknown ();
 219                         // not what MS seems to do,
 220                         // but IUnknown is identity in COM
 221                         return iunknown.ToInt32 ();
 222                 }
 223
 224                 [DllImport ("ole32.dll", CallingConvention = CallingConvention.StdCall, ExactSpelling = true, PreserveSig = true)]
 225                 static extern int CoCreateInstance (
 226                    [In, MarshalAs (UnmanagedType.LPStruct)] Guid rclsid,
 227                    IntPtr pUnkOuter,
 228                    uint dwClsContext,
 229                   [In, MarshalAs (UnmanagedType.LPStruct)] Guid riid,
 230                         out IntPtr pUnk);
 231         }
 232 }
 233 #endif