/// <summary>
/// This method validates that the given weak reference is alive.
/// 1. IWeakReference->Resolve method returns the target's interface for the mapping IID passed to it.
/// 2. If the object is not alive it returns null.
/// 2. From the returned interface we get or create a new RCW and return it.
/// </summary>
/// <returns></returns>
internal unsafe object Resolve()
{
IntPtr pInspectable;
__com_IWeakReference *pComIWeakReference = (__com_IWeakReference *)m_pComWeakRef;
Guid inspectableIID = Interop.COM.IID_IInspectable;
int result = CalliIntrinsics.StdCall__int(
pComIWeakReference->pVtable->pfnResolve,
m_pComWeakRef,
&inspectableIID,
&pInspectable);
if (result >= 0 && pInspectable != IntPtr.Zero)
{
try
{
return(McgMarshal.ComInterfaceToObject(pInspectable, McgModuleManager.IInspectable));
}
finally
{
// Release the pInspectable.
McgMarshal.ComRelease(pInspectable);
}
}
return(null);
}
static object ComInterfaceToObjectInternal_NoManagedUnboxing(
IntPtr pComItf,
RuntimeTypeHandle interfaceType,
RuntimeTypeHandle classTypeInSignature,
CreateComObjectFlags flags)
{
if (pComItf == default(IntPtr))
{
return(null);
}
//
// Is this a CCW?
//
ComCallableObject ccw;
if (ComCallableObject.TryGetCCW(pComItf, out ccw))
{
return(ccw.TargetObject);
}
//
// This pointer is not a CCW, but we need to do one additional check here for aggregation
// In case the COM pointer is a interface implementation from native, but the outer object is a
// managed object
//
IntPtr pComIdentityIUnknown = McgMarshal.ComQueryInterfaceNoThrow(pComItf, ref Interop.COM.IID_IUnknown);
if (pComIdentityIUnknown == default(IntPtr))
{
throw new InvalidCastException();
}
try
{
//
// Check whether the identity COM pointer to see if it is a aggregating CCW
//
if (ComCallableObject.TryGetCCW(pComIdentityIUnknown, out ccw))
{
return(ccw.TargetObject);
}
//
// Nope, not a CCW - let's go down our RCW creation code path
//
return(ComInterfaceToComObjectInternal(
pComItf,
pComIdentityIUnknown,
interfaceType,
classTypeInSignature,
ContextCookie.Default,
flags
));
}
finally
{
McgMarshal.ComRelease(pComIdentityIUnknown);
}
}
/// <summary>
/// Returns runtime class name for a specific object
/// </summary>
internal static string GetRuntimeClassName(Object obj)
{
#if ENABLE_MIN_WINRT
System.IntPtr pWinRTItf = default(IntPtr);
try
{
pWinRTItf = McgMarshal.ObjectToIInspectable(obj);
if (pWinRTItf == default(IntPtr))
{
return(String.Empty);
}
else
{
return(GetRuntimeClassName(pWinRTItf));
}
}
finally
{
if (pWinRTItf != default(IntPtr))
{
McgMarshal.ComRelease(pWinRTItf);
}
}
#else
return(string.Empty);
#endif
}
/// <summary>
/// Returns runtime class name for a specific object
/// </summary>
internal static string GetRuntimeClassName(Object obj)
{
#if ENABLE_WINRT
System.IntPtr pWinRTItf = default(IntPtr);
try
{
pWinRTItf = McgMarshal.ObjectToIInspectable(obj);
if (pWinRTItf == default(IntPtr))
{
return(String.Empty);
}
else
{
return(GetRuntimeClassName(pWinRTItf));
}
}
finally
{
if (pWinRTItf != default(IntPtr))
{
McgMarshal.ComRelease(pWinRTItf);
}
}
#else
throw new PlatformNotSupportedException("GetRuntimeClassName");
#endif
}
/// <summary>
/// Release a IStream that has marshalled data in it
/// </summary>
internal static void SafeReleaseStream(IntPtr pStream)
{
Debug.Assert(pStream != default(IntPtr));
#if ENABLE_WINRT
// Release marshalled data and ignore any error
ExternalInterop.CoReleaseMarshalData(pStream);
McgMarshal.ComRelease(pStream);
#else
throw new PlatformNotSupportedException("SafeReleaseStream");
#endif
}
#pragma warning restore 649, 169
/// <summary>
/// This method gets called every time the WeakReference or WeakReference'1 set the Target.
/// We can have 4 possible combination here.
/// a. Target is a GC object and it is either getting set for the first time or previous object is also GC object.
/// In this case we do not need to do anything.
///
/// b. Target is a GC object and previous target was __ComObject
/// i. We remove the element from ConditionalWeakTable.
/// ii. When the GC collects this ComWeakReference the finalizer will ensure that the native object is released.
///
/// c. Target is a __ComObject and the previous target was null or GC object.
/// We simply add the new target to the dictionary.
///
/// d. Target is a __COmObject and the previous object was __COmObject.
/// i. We first remove the element from the ConditionalWeakTable.
/// ii. When the GC collects the previous ComWeakReference the finalizer will ensure that the native object is released.
/// iii. We add the new ComWeakReference to the conditionalWeakTable.
/// </summary>
/// <param name="weakReference"></param>
/// <param name="target"></param>
public static unsafe void SetTarget(object weakReference, object target)
{
Contract.Assert(weakReference != null);
// Check if this weakReference is already associated with a native target.
ComWeakReference pOldComWeakReference;
if (s_COMWeakReferenceTable.TryGetValue(weakReference, out pOldComWeakReference))
{
// Remove the previous target.
// We do not have to release the native ComWeakReference since it will be done as part of the finalizer.
s_COMWeakReferenceTable.Remove(weakReference);
}
// Now check whether the current target is __ComObject.
// However, we don't want to pass the QI to a managed object deriving from native object - we
// would end up passing the QI to back the CCW and end up stack overflow
__ComObject comObject = target as __ComObject;
if (comObject != null && !comObject.ExtendsComObject)
{
// Get the IWeakReferenceSource for the given object
IntPtr pWeakRefSource = McgMarshal.ObjectToComInterface(comObject, McgModuleManager.IWeakReferenceSource);
if (pWeakRefSource != IntPtr.Zero)
{
IntPtr pWeakRef = IntPtr.Zero;
try
{
// Now that we have the IWeakReferenceSource , we need to call the GetWeakReference method to get the corresponding IWeakReference
__com_IWeakReferenceSource *pComWeakRefSource = (__com_IWeakReferenceSource *)pWeakRefSource;
int result = CalliIntrinsics.StdCall <int>(
pComWeakRefSource->pVtable->pfnGetWeakReference,
pWeakRefSource,
out pWeakRef);
if (result >= 0 && pWeakRef != IntPtr.Zero)
{
// Since we have already checked s_COMWeakReferenceTable for the weak reference, we can simply add the entry w/o checking.
// PS - We do not release the pWeakRef as it should be alive until the ComWeakReference is alive.
s_COMWeakReferenceTable.Add(weakReference, new ComWeakReference(ref pWeakRef));
}
}
finally
{
McgMarshal.ComSafeRelease(pWeakRef);
McgMarshal.ComRelease(pWeakRefSource);
}
}
}
}
/// <summary>
/// Returns the existing RCW or create a new RCW from the COM interface pointer
/// NOTE: Don't use this overload if you already have the identity IUnknown
/// </summary>
/// <param name="expectedContext">
/// The current context of this thread. If it is passed and is not Default, we'll check whether the
/// returned RCW from cache matches this expected context. If it is not a match (from a different
/// context, and is not free threaded), we'll go ahead ignoring the cached entry, and create a new
/// RCW instead - which will always end up in the current context
/// We'll skip the check if current == ContextCookie.Default.
/// </param>
internal static object ComInterfaceToComObject(
IntPtr pComItf,
RuntimeTypeHandle interfaceType,
RuntimeTypeHandle classTypeInSigature,
ContextCookie expectedContext,
CreateComObjectFlags flags
)
{
Debug.Assert(expectedContext.IsDefault || expectedContext.IsCurrent);
//
// Get identity IUnknown for lookup
//
IntPtr pComIdentityIUnknown = McgMarshal.ComQueryInterfaceNoThrow(pComItf, ref Interop.COM.IID_IUnknown);
if (pComIdentityIUnknown == default(IntPtr))
{
throw new InvalidCastException();
}
try
{
object obj = ComInterfaceToComObjectInternal(
pComItf,
pComIdentityIUnknown,
interfaceType,
classTypeInSigature,
expectedContext,
flags
);
return(obj);
}
finally
{
McgMarshal.ComRelease(pComIdentityIUnknown);
}
}
public static int Release(IntPtr pUnk)
{
return(McgMarshal.ComRelease(pUnk));
}
/// <summary>
/// Returns the existing RCW or create a new RCW from the COM interface pointer
/// NOTE: This does not do any unboxing at all.
/// </summary>
/// <param name="expectedContext">
/// The current context of this thread. If it is passed and is not Default, we'll check whether the
/// returned RCW from cache matches this expected context. If it is not a match (from a different
/// context, and is not free threaded), we'll go ahead ignoring the cached entry, and create a new
/// RCW instead - which will always end up in the current context
/// We'll skip the check if current == ContextCookie.Default.
/// </param>
private static object ComInterfaceToComObjectInternal_NoCache(
IntPtr pComItf,
IntPtr pComIdentityIUnknown,
RuntimeTypeHandle interfaceType,
RuntimeTypeHandle classTypeInSignature,
ContextCookie expectedContext,
CreateComObjectFlags flags,
out string className
)
{
className = null;
//
// Lookup RCW in global RCW cache based on the identity IUnknown
//
__ComObject comObject = ComObjectCache.Lookup(pComIdentityIUnknown);
if (comObject != null)
{
bool useThisComObject = true;
if (!expectedContext.IsDefault)
{
//
// Make sure the returned RCW matches the context we specify (if any)
//
if (!comObject.IsFreeThreaded &&
!comObject.ContextCookie.Equals(expectedContext))
{
//
// This is a mismatch.
// We only care about context for WinRT factory RCWs (which is the only place we are
// passing in the context right now).
// When we get back a WinRT factory RCW created in a different context. This means the
// factory is a singleton, and the returned IActivationFactory could be either one of
// the following:
// 1) A raw pointer, and it acts like a free threaded object
// 2) A proxy that is used across different contexts. It might maintain a list of contexts
// that it is marshaled to, and will fail to be called if it is not marshaled to this
// context yet.
//
// In this case, it is unsafe to use this RCW in this context and we should proceed
// to create a duplicated one instead. It might make sense to have a context-sensitive
// RCW cache but I don't think this case will be common enough to justify it
//
// @TODO: Check for DCOM proxy as well
useThisComObject = false;
}
}
if (useThisComObject)
{
//
// We found one - AddRef and return
//
comObject.AddRef();
return(comObject);
}
}
string winrtClassName = null;
bool isSealed = false;
if (!classTypeInSignature.IsNull())
{
isSealed = classTypeInSignature.IsSealed();
}
//
// Only look at runtime class name if the class type in signature is not sealed
// NOTE: In the case of System.Uri, we are not pass the class type, only the interface
//
if (!isSealed &&
(flags & CreateComObjectFlags.SkipTypeResolutionAndUnboxing) == 0)
{
IntPtr pInspectable;
bool needRelease = false;
if (interfaceType.IsSupportIInspectable())
{
//
// Use the interface pointer as IInspectable as we know it is indeed a WinRT interface that
// derives from IInspectable
//
pInspectable = pComItf;
}
else if ((flags & CreateComObjectFlags.IsWinRTObject) != 0)
{
//
// Otherwise, if someone tells us that this is a WinRT object, but we don't have a
// IInspectable interface at hand, we'll QI for it
//
pInspectable = McgMarshal.ComQueryInterfaceNoThrow(pComItf, ref Interop.COM.IID_IInspectable);
needRelease = true;
}
else
{
pInspectable = default(IntPtr);
}
try
{
if (pInspectable != default(IntPtr))
{
className = McgComHelpers.GetRuntimeClassName(pInspectable);
winrtClassName = className;
}
}
finally
{
if (needRelease && pInspectable != default(IntPtr))
{
McgMarshal.ComRelease(pInspectable);
pInspectable = default(IntPtr);
}
}
}
//
// 1. Prefer using the class returned from GetRuntimeClassName
// 2. Otherwise use the class (if there) in the signature
// 3. Out of options - create __ComObject
//
RuntimeTypeHandle classTypeToCreateRCW = default(RuntimeTypeHandle);
RuntimeTypeHandle interfaceTypeFromName = default(RuntimeTypeHandle);
if (!String.IsNullOrEmpty(className))
{
if (!McgModuleManager.TryGetClassTypeFromName(className, out classTypeToCreateRCW))
{
//
// If we can't find the class name in our map, try interface as well
// Such as IVector<Int32>
// This apparently won't work if we haven't seen the interface type in MCG
//
McgModuleManager.TryGetInterfaceTypeFromName(className, out interfaceTypeFromName);
}
}
if (classTypeToCreateRCW.IsNull())
{
classTypeToCreateRCW = classTypeInSignature;
}
// Use identity IUnknown to create the new RCW
// @TODO: Transfer the ownership of ref count to the RCW
if (classTypeToCreateRCW.IsNull())
{
//
// Create a weakly typed RCW because we have no information about this particular RCW
// @TODO - what if this RCW is not seen by MCG but actually exists in WinMD and therefore we
// are missing GCPressure and ComMarshallingType information for this object?
//
comObject = new __ComObject(pComIdentityIUnknown, default(RuntimeTypeHandle));
}
else
{
//
// Create a strongly typed RCW based on RuntimeTypeHandle
//
comObject = CreateComObjectInternal(classTypeToCreateRCW, pComIdentityIUnknown); // Use identity IUnknown to create the new RCW
}
#if DEBUG
//
// Remember the runtime class name for debugging purpose
// This way you can tell what the class name is, even when we failed to create a strongly typed
// RCW for it
//
comObject.m_runtimeClassName = className;
#endif
//
// Make sure we QI for that interface
//
if (!interfaceType.IsNull())
{
comObject.QueryInterface_NoAddRef_Internal(interfaceType, /* cacheOnly= */ false, /* throwOnQueryInterfaceFailure= */ false);
}
return(comObject);
}