Drop global Instance of JavaMarshalValueManager

src/Microsoft.Android.Runtime.NativeAOT/Java.Interop/JreRuntime.cs

@@ -61,7 +61,7 @@ static NativeAotRuntimeOptions CreateJreVM (NativeAotRuntimeOptions builder)
 			builder.TypeManager     ??= CreateDefaultTypeManager ();
 #endif  // NET
 
-			builder.ValueManager            ??= JavaMarshalValueManager.Instance;
+			builder.ValueManager            ??= new JavaMarshalValueManager ();
 			builder.ObjectReferenceManager  ??= new Android.Runtime.AndroidObjectReferenceManager ();
 
 			if (builder.InvocationPointer != IntPtr.Zero || builder.EnvironmentPointer != IntPtr.Zero)

src/Mono.Android/Android.Runtime/JNIEnvInit.cs

@@ -187,7 +187,11 @@ internal static JniRuntime.JniValueManager CreateValueManager ()
 				return new AndroidValueManager ();
 			}
 
-			if (RuntimeFeature.IsCoreClrRuntime || RuntimeFeature.IsNativeAotRuntime) {
+			if (RuntimeFeature.IsCoreClrRuntime) {
+				return new JavaMarshalValueManager ();
+			}
+
+			if (RuntimeFeature.IsNativeAotRuntime) {
 				return new JavaMarshalValueManager ();
 			}
 

src/Mono.Android/Android.Runtime/RuntimeNativeMethods.cs

@@ -125,8 +125,9 @@ internal unsafe static partial class RuntimeNativeMethods
 		[LibraryImport (RuntimeConstants.InternalDllName)]
 		[UnmanagedCallConv (CallConvs = new[] { typeof (CallConvCdecl) })]
 		internal static partial delegate* unmanaged<MarkCrossReferencesArgs*, void> clr_initialize_gc_bridge (
+			IntPtr java_marshal_value_manager_handle,
 			delegate* unmanaged<MarkCrossReferencesArgs*, void> bridge_processing_started_callback,
-			delegate* unmanaged<MarkCrossReferencesArgs*, void> bridge_processing_finished_callback);
+			delegate* unmanaged<IntPtr, MarkCrossReferencesArgs*, void> bridge_processing_finished_callback);
 
 		[MethodImplAttribute(MethodImplOptions.InternalCall)]
 		internal static extern void monodroid_unhandled_exception (Exception javaException);

src/Mono.Android/Microsoft.Android.Runtime/JavaMarshalValueManager.cs

@@ -27,18 +27,11 @@ class JavaMarshalValueManager : JniRuntime.JniValueManager
 
 	bool disposed;
 
-	static JavaMarshalValueManager? s_instance;
-
-	public static JavaMarshalValueManager Instance =>
-		s_instance ?? throw new InvalidOperationException ("JavaMarshalValueManager has not been initialized. Call the constructor first.");
-
-	unsafe internal JavaMarshalValueManager ()
+	public unsafe JavaMarshalValueManager ()
 	{
-		var previous = Interlocked.CompareExchange (ref s_instance, this, null);
-		Debug.Assert (previous is null, "JavaMarshalValueManager must only be created once.");
-
-		// There can only be one instance because JavaMarshal.Initialize can only be called once.
-		var mark_cross_references_ftn = RuntimeNativeMethods.clr_initialize_gc_bridge (&BridgeProcessingStarted, &BridgeProcessingFinished);
+		var javaMarshalValueManagerHandle = new GCHandle<JavaMarshalValueManager> (this);
+		var mark_cross_references_ftn = RuntimeNativeMethods.clr_initialize_gc_bridge (
+			GCHandle<JavaMarshalValueManager>.ToIntPtr (javaMarshalValueManagerHandle), &BridgeProcessingStarted, &BridgeProcessingFinished);
 		JavaMarshal.Initialize (mark_cross_references_ftn);
 	}
 
@@ -356,6 +349,12 @@ public static GCHandle GetAssociatedGCHandle (HandleContext* context)
 
 		public static unsafe void EnsureAllContextsAreOurs (MarkCrossReferencesArgs* mcr)
 		{
+// This call site is reachable on all platforms. 'MarkCrossReferencesArgs.ComponentCount' is only supported on: 'android'.
+// This call site is reachable on all platforms. 'MarkCrossReferencesArgs.Components' is only supported on: 'android'.
+// This call site is reachable on all platforms. 'StronglyConnectedComponent.Count' is only supported on: 'android'.
+// This call site is reachable on all platforms. 'StronglyConnectedComponent.Contexts' is only supported on: 'android'.
+#pragma warning disable CA1416
+
 			lock (referenceTrackingHandles) {
 				for (nuint i = 0; i < mcr->ComponentCount; i++) {
 					StronglyConnectedComponent component = mcr->Components [i];
@@ -375,7 +374,9 @@ static void EnsureContextIsOurs (IntPtr context)
 				if (!referenceTrackingHandles.ContainsKey (context)) {
 					throw new InvalidOperationException ("Unknown reference tracking handle.");
 				}
-			}	
+			}
+
+#pragma warning restore CA1416
 		}
 
 		public static HandleContext* Alloc (IJavaPeerable peer)
@@ -422,20 +423,32 @@ static unsafe void BridgeProcessingStarted (MarkCrossReferencesArgs* mcr)
 	}
 
 	[UnmanagedCallersOnly]
-	static unsafe void BridgeProcessingFinished (MarkCrossReferencesArgs* mcr)
+	static unsafe void BridgeProcessingFinished (IntPtr javaMarshalValueManagerHandle, MarkCrossReferencesArgs* mcr)
 	{
 		if (mcr == null) {
 			throw new ArgumentNullException (nameof (mcr), "MarkCrossReferencesArgs should never be null.");
 		}
 
-		ReadOnlySpan<GCHandle> handlesToFree = ProcessCollectedContexts (mcr);
+		JavaMarshalValueManager instance = GCHandle<JavaMarshalValueManager>.FromIntPtr (javaMarshalValueManagerHandle).Target;
+
+		ReadOnlySpan<GCHandle> handlesToFree = instance.ProcessCollectedContexts (mcr);
+
+
+// This call site is reachable on all platforms. 'JavaMarshal.FinishCrossReferenceProcessing(MarkCrossReferencesArgs*, ReadOnlySpan<GCHandle>)' is only supported on: 'android'.
+#pragma warning disable CA1416
 		JavaMarshal.FinishCrossReferenceProcessing (mcr, handlesToFree);
+#pragma warning restore CA1416
 	}
 
-	static unsafe ReadOnlySpan<GCHandle> ProcessCollectedContexts (MarkCrossReferencesArgs* mcr)
+	unsafe ReadOnlySpan<GCHandle> ProcessCollectedContexts (MarkCrossReferencesArgs* mcr)
 	{
 		List<GCHandle> handlesToFree = [];
-		JavaMarshalValueManager instance = Instance;
+
+// This call site is reachable on all platforms. 'MarkCrossReferencesArgs.ComponentCount' is only supported on: 'android'.
+// This call site is reachable on all platforms. 'MarkCrossReferencesArgs.Components' is only supported on: 'android'.
+// This call site is reachable on all platforms. 'StronglyConnectedComponent.Count' is only supported on: 'android'.
+// This call site is reachable on all platforms. 'StronglyConnectedComponent.Contexts' is only supported on: 'android'.
+#pragma warning disable CA1416
 
 		for (int i = 0; (nuint)i < mcr->ComponentCount; i++) {
 			StronglyConnectedComponent component = mcr->Components [i];
@@ -444,6 +457,8 @@ static unsafe ReadOnlySpan<GCHandle> ProcessCollectedContexts (MarkCrossReferenc
 			}
 		}
 
+#pragma warning restore CA1416
+
 		void ProcessContext (HandleContext* context)
 		{
 			if (context == null) {
@@ -460,7 +475,7 @@ void ProcessContext (HandleContext* context)
 			// Note: modifying the RegisteredInstances dictionary while processing the collected contexts
 			// is tricky and can lead to deadlocks, so we remember which contexts were collected and we will free
 			// them later outside of the bridge processing loop.
-			instance.CollectedContexts.Enqueue ((IntPtr)context);
+			CollectedContexts.Enqueue ((IntPtr)context);
 
 			// important: we must not free the handle before passing it to JavaMarshal.FinishCrossReferenceProcessing
 			handlesToFree.Add (handle);

src/native/clr/host/gc-bridge.cc

@@ -74,7 +74,7 @@ void GCBridge::bridge_processing () noexcept
 		BridgeProcessing bridge_processing {args};
 		bridge_processing.process ();
 
-		bridge_processing_finished_callback (args);
+		bridge_processing_finished_callback (java_marshal_value_manager_handle, args);
 	}
 }
 

src/native/clr/host/internal-pinvokes-shared.cc

@@ -45,10 +45,11 @@ void _monodroid_weak_gref_delete (jobject handle, char type, const char *threadN
 }
 
 BridgeProcessingFtn clr_initialize_gc_bridge (
+	intptr_t java_marshal_value_manager_handle,
 	BridgeProcessingStartedFtn bridge_processing_started_callback,
 	BridgeProcessingFinishedFtn bridge_processing_finished_callback) noexcept
 {
-	return GCBridge::initialize_callback (bridge_processing_started_callback, bridge_processing_finished_callback);
+	return GCBridge::initialize_callback (java_marshal_value_manager_handle, bridge_processing_started_callback, bridge_processing_finished_callback);
 }
 
 void monodroid_log (LogLevel level, LogCategories category, const char *message) noexcept

src/native/clr/include/host/gc-bridge.hh

@@ -50,7 +50,7 @@ struct MarkCrossReferencesArgs
 };
 
 using BridgeProcessingStartedFtn = void (*)(MarkCrossReferencesArgs*);
-using BridgeProcessingFinishedFtn = void (*)(MarkCrossReferencesArgs*);
+using BridgeProcessingFinishedFtn = void (*)(intptr_t, MarkCrossReferencesArgs*);
 using BridgeProcessingFtn = void (*)(MarkCrossReferencesArgs*);
 
 namespace xamarin::android {
@@ -61,6 +61,7 @@ namespace xamarin::android {
 		static void initialize_on_runtime_init (JNIEnv *env, jclass runtimeClass) noexcept;
 
 		static BridgeProcessingFtn initialize_callback (
+			intptr_t java_marshal_value_manager,
 			BridgeProcessingStartedFtn bridge_processing_started,
 			BridgeProcessingFinishedFtn bridge_processing_finished) noexcept
 		{
@@ -69,6 +70,7 @@ namespace xamarin::android {
 			abort_unless (GCBridge::bridge_processing_started_callback == nullptr, "GC bridge processing started callback is already set");
 			abort_unless (GCBridge::bridge_processing_finished_callback == nullptr, "GC bridge processing finished callback is already set");
 
+			GCBridge::java_marshal_value_manager_handle = java_marshal_value_manager;
 			GCBridge::bridge_processing_started_callback = bridge_processing_started;
 			GCBridge::bridge_processing_finished_callback = bridge_processing_finished;
 
@@ -89,6 +91,7 @@ namespace xamarin::android {
 		static inline jobject Runtime_instance = nullptr;
 		static inline jmethodID Runtime_gc = nullptr;
 
+		static inline intptr_t java_marshal_value_manager_handle;
 		static inline BridgeProcessingStartedFtn bridge_processing_started_callback = nullptr;
 		static inline BridgeProcessingFinishedFtn bridge_processing_finished_callback = nullptr;
 

src/native/clr/include/runtime-base/internal-pinvokes.hh

@@ -18,6 +18,7 @@ extern "C" {
 	const char* clr_typemap_managed_to_java (const char *typeName, const uint8_t *mvid) noexcept;
 	bool clr_typemap_java_to_managed (const char *java_type_name, char const** assembly_name, uint32_t *managed_type_token_id) noexcept;
 	BridgeProcessingFtn clr_initialize_gc_bridge (
+		intptr_t java_marshal_value_manager_handle,
 		BridgeProcessingStartedFtn bridge_processing_started_callback,
 		BridgeProcessingFinishedFtn mark_cross_references_callback) noexcept;
 	void monodroid_log (xamarin::android::LogLevel level, LogCategories category, const char *message) noexcept;