Expose api's for Context on ObjectReference.

src/WinRT.Runtime/ComWrappersSupport.cs

@@ -75,14 +75,15 @@ public static void MarshalDelegateInvoke<T>(IntPtr thisPtr, Action<T> invoke)
 
         // If we are free threaded, we do not need to keep track of context.
         // This can either be if the object implements IAgileObject or the free threaded marshaler.
-        internal unsafe static bool IsFreeThreaded(IObjectReference objRef)
+        internal unsafe static bool IsFreeThreaded(IntPtr iUnknown)
         {
-            if (objRef.TryAs(InterfaceIIDs.IAgileObject_IID, out var agilePtr) >= 0)
+            if (Marshal.QueryInterface(iUnknown, ref Unsafe.AsRef(InterfaceIIDs.IAgileObject_IID), out var agilePtr) >= 0)
             {
                 Marshal.Release(agilePtr);
                 return true;
             }
-            else if (objRef.TryAs(InterfaceIIDs.IMarshal_IID, out var marshalPtr) >= 0)
+
+            if (Marshal.QueryInterface(iUnknown, ref Unsafe.AsRef(InterfaceIIDs.IMarshal_IID), out var marshalPtr) >= 0)
             {
                 try
                 {
@@ -103,6 +104,14 @@ internal unsafe static bool IsFreeThreaded(IObjectReference objRef)
             return false;
         }
 
+        internal unsafe static bool IsFreeThreaded(IObjectReference objRef)
+        {
+            var isFreeThreaded = IsFreeThreaded(objRef.ThisPtr);
+            // ThisPtr is owned by objRef, so need to make sure objRef stays alive.
+            GC.KeepAlive(objRef);
+            return isFreeThreaded;
+        }
+
         public static IObjectReference GetObjectReferenceForInterface(IntPtr externalComObject)
         {
             return GetObjectReferenceForInterface<IUnknownVftbl>(externalComObject);
@@ -115,21 +124,7 @@ public static ObjectReference<T> GetObjectReferenceForInterface<T>(IntPtr extern
                 return null;
             }
 
-            ObjectReference<T> objRef = ObjectReference<T>.FromAbi(externalComObject);
-            if (IsFreeThreaded(objRef))
-            {
-                return objRef;
-            }
-            else
-            {
-                using (objRef)
-                {
-                    return new ObjectReferenceWithContext<T>(
-                        objRef.GetRef(),
-                        Context.GetContextCallback(),
-                        Context.GetContextToken());
-                }
-            }
+            return ObjectReference<T>.FromAbi(externalComObject);
         }
 
         public static ObjectReference<T> GetObjectReferenceForInterface<T>(IntPtr externalComObject, Guid iid)
@@ -144,31 +139,14 @@ internal static ObjectReference<T> GetObjectReferenceForInterface<T>(IntPtr exte
                 return null;
             }
 
-            ObjectReference<T> objRef;
             if (requireQI)
             {
                 Marshal.ThrowExceptionForHR(Marshal.QueryInterface(externalComObject, ref iid, out IntPtr ptr));
-                objRef = ObjectReference<T>.Attach(ref ptr);
+                return ObjectReference<T>.Attach(ref ptr);
             }
             else
             {
-                objRef = ObjectReference<T>.FromAbi(externalComObject);
-            }
-
-            if (IsFreeThreaded(objRef))
-            {
-                return objRef;
-            }
-            else
-            {
-                using (objRef)
-                {
-                    return new ObjectReferenceWithContext<T>(
-                        objRef.GetRef(),
-                        Context.GetContextCallback(),
-                        Context.GetContextToken(),
-                        iid);
-                }
+                return ObjectReference<T>.FromAbi(externalComObject);
             }
         }
 
@@ -487,7 +465,12 @@ private static Func<IInspectable, object> CreateCustomTypeMappingFactory(Type cu
             }
 
             var fromAbiMethodFunc = (Func<IntPtr, object>) fromAbiMethod.CreateDelegate(typeof(Func<IntPtr, object>));
-            return (IInspectable obj) => fromAbiMethodFunc(obj.ThisPtr);
+            return (IInspectable obj) =>
+            {
+                var fromAbiMethod = fromAbiMethodFunc(obj.ThisPtr);
+                GC.KeepAlive(obj);
+                return fromAbiMethod;
+            };
         }
 
         internal static Func<IInspectable, object> CreateTypedRcwFactory(

src/WinRT.Runtime/ComWrappersSupport.net5.cs

@@ -350,8 +350,7 @@ public unsafe static void Init(
                 // otherwise the new instance will be used. Since the inner was composed
                 // it should answer immediately without going through the outer. Either way
                 // the reference count will go to the new instance.
-                Guid iid = IReferenceTrackerVftbl.IID;
-                int hr = Marshal.QueryInterface(objRef.ThisPtr, ref iid, out referenceTracker);
+                int hr = Marshal.QueryInterface(objRef.ThisPtr, ref Unsafe.AsRef(IReferenceTrackerVftbl.IID), out referenceTracker);
                 if (hr != 0)
                 {
                     referenceTracker = default;
@@ -450,9 +449,8 @@ public unsafe static void Init(
         public unsafe static void Init(IObjectReference objRef, bool addRefFromTrackerSource = true)
         {
             if (objRef.ReferenceTrackerPtr == IntPtr.Zero)
-            {
-                Guid iid = IReferenceTrackerVftbl.IID;
-                int hr = Marshal.QueryInterface(objRef.ThisPtr, ref iid, out var referenceTracker);
+            {
+                int hr = Marshal.QueryInterface(objRef.ThisPtr, ref Unsafe.AsRef(IReferenceTrackerVftbl.IID), out var referenceTracker);
                 if (hr == 0)
                 {
                     // WinUI scenario

src/WinRT.Runtime/ExceptionHelpers.cs

@@ -364,6 +364,7 @@ public static void ReportUnhandledError(Exception ex)
                 if (restrictedErrorInfoRef != null)
                 {
                     roReportUnhandledError(restrictedErrorInfoRef.ThisPtr);
+                    GC.KeepAlive(restrictedErrorInfoRef);
                 }
             }
         }

src/WinRT.Runtime/Marshalers.cs

@@ -1581,8 +1581,7 @@ public static T FromAbi(IntPtr ptr)
             IntPtr iunknownPtr = IntPtr.Zero;
             try
             {
-                Guid iid_iunknown = IUnknownVftbl.IID;
-                Marshal.QueryInterface(ptr, ref iid_iunknown, out iunknownPtr);
+                Marshal.QueryInterface(ptr, ref Unsafe.AsRef(IUnknownVftbl.IID), out iunknownPtr);
                 if (IUnknownVftbl.IsReferenceToManagedObject(iunknownPtr))
                 {
                     return (T)ComWrappersSupport.FindObject<object>(iunknownPtr);

src/WinRT.Runtime/MatchingRefApiCompatBaseline.txt

@@ -131,4 +131,6 @@ MembersMustExist : Member 'public System.String WinRT.WindowsRuntimeTypeAttribut
 TypesMustExist : Type 'WinRT.WinRTExposedTypeAttribute' does not exist in the reference but it does exist in the implementation.
 MembersMustExist : Member 'public T ABI.System.Nullable<T>.GetValue(WinRT.IInspectable)' does not exist in the reference but it does exist in the implementation.
 TypesMustExist : Type 'WinRT.EventRegistrationTokenTable<T>' does not exist in the reference but it does exist in the implementation.
-Total Issues: 132
+MembersMustExist : Member 'public System.Boolean WinRT.IObjectReference.IsFreeThreaded.get()' does not exist in the reference but it does exist in the implementation.
+MembersMustExist : Member 'public System.Boolean WinRT.IObjectReference.IsInCurrentContext.get()' does not exist in the reference but it does exist in the implementation.
+Total Issues: 134

src/WinRT.Runtime/ObjectReference.cs

@@ -36,6 +36,17 @@ public IntPtr ThisPtr
             }
         }
 
+        public bool IsFreeThreaded => GetContextToken() == IntPtr.Zero;
+
+        public bool IsInCurrentContext
+        {
+            get
+            {
+                var contextToken = GetContextToken();
+                return contextToken == IntPtr.Zero || contextToken == Context.GetContextToken();
+            }
+        }
+
         private protected IntPtr ThisPtrFromOriginalContext
         {
             get
@@ -306,7 +317,7 @@ internal bool Resurrect()
         protected virtual unsafe void AddRef(bool refFromTrackerSource)
         {
             Marshal.AddRef(ThisPtr);
-            if(refFromTrackerSource)
+            if (refFromTrackerSource)
             {
                 AddRefFromTrackerSource();
             }
@@ -382,6 +393,11 @@ private protected virtual IntPtr GetThisPtrForCurrentContext()
             return ThisPtrFromOriginalContext;
         }
 
+        private protected virtual IntPtr GetContextToken()
+        {
+            return IntPtr.Zero;
+        }
+
         public ObjectReferenceValue AsValue()
         {
             // Sharing ptr with objref.
@@ -423,18 +439,7 @@ public T Vftbl
             }
         }
 
-        public static ObjectReference<T> Attach(ref IntPtr thisPtr)
-        {
-            if (thisPtr == IntPtr.Zero)
-            {
-                return null;
-            }
-            var obj = new ObjectReference<T>(thisPtr);
-            thisPtr = IntPtr.Zero;
-            return obj;
-        }
-
-        ObjectReference(IntPtr thisPtr, T vftblT) :
+        private protected ObjectReference(IntPtr thisPtr, T vftblT) :
             base(thisPtr)
         {
             _vftbl = vftblT;
@@ -445,15 +450,51 @@ private protected ObjectReference(IntPtr thisPtr) :
         {
         }
 
-        public static unsafe ObjectReference<T> FromAbi(IntPtr thisPtr, T vftblT)
+        public static ObjectReference<T> Attach(ref IntPtr thisPtr)
         {
             if (thisPtr == IntPtr.Zero)
             {
                 return null;
             }
+
+            if (ComWrappersSupport.IsFreeThreaded(thisPtr))
+            {
+                var obj = new ObjectReference<T>(thisPtr);
+                thisPtr = IntPtr.Zero;
+                return obj;
+            }
+            else
+            {
+                var obj = new ObjectReferenceWithContext<T>(
+                    thisPtr,
+                    Context.GetContextCallback(),
+                    Context.GetContextToken());
+                thisPtr = IntPtr.Zero;
+                return obj;
+            }
+        }
+
+        public static unsafe ObjectReference<T> FromAbi(IntPtr thisPtr, T vftblT)
+        {
+            if (thisPtr == IntPtr.Zero)
+            {
+                return null;
+            }
+
             Marshal.AddRef(thisPtr);
-            var obj = new ObjectReference<T>(thisPtr, vftblT);
-            return obj;
+            if (ComWrappersSupport.IsFreeThreaded(thisPtr))
+            {
+                var obj = new ObjectReference<T>(thisPtr, vftblT);
+                return obj;
+            }
+            else
+            {
+                var obj = new ObjectReferenceWithContext<T>(
+                    thisPtr,
+                    Context.GetContextCallback(),
+                    Context.GetContextToken());
+                return obj;
+            }
         }
 
         public static ObjectReference<T> FromAbi(IntPtr thisPtr)
@@ -504,7 +545,7 @@ internal sealed class ObjectReferenceWithContext<
 #endif
         T> : ObjectReference<T>
     {
-        private readonly IntPtr _contextCallbackPtr;
+        private readonly IntPtr _contextCallbackPtr;
         private readonly IntPtr _contextToken;
 
         private volatile ConcurrentDictionary<IntPtr, ObjectReference<T>> __cachedContext;
@@ -520,7 +561,7 @@ private ConcurrentDictionary<IntPtr, ObjectReference<T>> Make_CachedContext()
         private volatile AgileReference __agileReference;
         private AgileReference AgileReference => _isAgileReferenceSet ? __agileReference : Make_AgileReference();
         private AgileReference Make_AgileReference()
-        { 
+        {
             Context.CallInContext(_contextCallbackPtr, _contextToken, InitAgileReference, null);
 
             // Set after CallInContext callback given callback can fail to occur.
@@ -536,9 +577,9 @@ void InitAgileReference()
         private readonly Guid _iid;
 
         internal ObjectReferenceWithContext(IntPtr thisPtr, IntPtr contextCallbackPtr, IntPtr contextToken)
-            :base(thisPtr)
+            : base(thisPtr)
         {
-            _contextCallbackPtr = contextCallbackPtr;
+            _contextCallbackPtr = contextCallbackPtr;
             _contextToken = contextToken;
         }
 
@@ -559,6 +600,11 @@ private protected override IntPtr GetThisPtrForCurrentContext()
             return cachedObjRef.ThisPtr;
         }
 
+        private protected override IntPtr GetContextToken()
+        {
+            return this._contextToken;
+        }
+
         private protected override T GetVftblForCurrentContext()
         {
             ObjectReference<T> cachedObjRef = GetCurrentContext();

src/cswinrt/code_writers.h

@@ -1935,13 +1935,13 @@ private static % _% = new %("%.%", %.IID);
     {
         auto objrefname = w.write_temp("%", bind<write_objref_type_name>(classType));
         w.write(R"(
-private static volatile FactoryObjectReference<IActivationFactoryVftbl> __%;
-private static FactoryObjectReference<IActivationFactoryVftbl> %
+private static volatile ObjectReference<IActivationFactoryVftbl> __%;
+private static ObjectReference<IActivationFactoryVftbl> %
 {
     get
     { 
         var factory = __%;
-        if (factory != null && factory.IsObjectInContext())
+        if (factory != null && factory.IsInCurrentContext)
         {
             return factory;
         }
@@ -1993,13 +1993,13 @@ private static ObjectReference<%> % => __% ?? Make__%();
         {
             auto objrefname = w.write_temp("%", bind<write_objref_type_name>(staticsType));
             w.write(R"(
-private static volatile FactoryObjectReference<%> __%;
-private static FactoryObjectReference<%> %
+private static volatile ObjectReference<%> __%;
+private static ObjectReference<%> %
 {
     get
     { 
         var factory = __%;
-        if (factory != null && factory.IsObjectInContext())
+        if (factory != null && factory.IsInCurrentContext)
         {
             return factory;
         }