dotnet · grendello · Sep 12, 2025 · Sep 1, 2025 · Sep 1, 2025 · Sep 2, 2025
@@ -233,6 +233,7 @@
   <PropertyGroup>
     <_MonoRuntimeFlavorDirName>mono</_MonoRuntimeFlavorDirName>
     <_CLRRuntimeFlavorDirName>clr</_CLRRuntimeFlavorDirName>
+    <_NativeAotRuntimeFlavorDirName>nativeaot</_NativeAotRuntimeFlavorDirName>
     <_RuntimeRedistDirName>redist</_RuntimeRedistDirName>
   </PropertyGroup>
 

@@ -49,6 +49,8 @@ Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "native-mono", "src\native\n
 EndProject
 Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "native-clr", "src\native\native-clr.csproj", "{9B42A5BB-74CB-46E2-BCE0-AF763A792551}"
 EndProject
+Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "native-nativeaot", "src\native\native-nativeaot.csproj", "{645E1718-C8C4-4C23-8A49-5A37E4ECF7ED}"
+EndProject
 Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "Tests", "Tests", "{CAB438D8-B0F5-4AF0-BEBD-9E2ADBD7B483}"
 EndProject
 Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "Xamarin.ProjectTools", "src\Xamarin.Android.Build.Tasks\Tests\Xamarin.ProjectTools\Xamarin.ProjectTools.csproj", "{2DD1EE75-6D8D-4653-A800-0A24367F7F38}"
@@ -211,6 +213,10 @@ Global
 		{9B42A5BB-74CB-46E2-BCE0-AF763A792551}.Debug|AnyCPU.Build.0 = Debug|Any CPU
 		{9B42A5BB-74CB-46E2-BCE0-AF763A792551}.Release|AnyCPU.ActiveCfg = Release|Any CPU
 		{9B42A5BB-74CB-46E2-BCE0-AF763A792551}.Release|AnyCPU.Build.0 = Release|Any CPU
+		{645E1718-C8C4-4C23-8A49-5A37E4ECF7ED}.Debug|AnyCPU.ActiveCfg = Debug|Any CPU
+		{645E1718-C8C4-4C23-8A49-5A37E4ECF7ED}.Debug|AnyCPU.Build.0 = Debug|Any CPU
+		{645E1718-C8C4-4C23-8A49-5A37E4ECF7ED}.Release|AnyCPU.ActiveCfg = Release|Any CPU
+		{645E1718-C8C4-4C23-8A49-5A37E4ECF7ED}.Release|AnyCPU.Build.0 = Release|Any CPU
 		{2DD1EE75-6D8D-4653-A800-0A24367F7F38}.Debug|AnyCPU.ActiveCfg = Debug|Any CPU
 		{2DD1EE75-6D8D-4653-A800-0A24367F7F38}.Debug|AnyCPU.Build.0 = Debug|Any CPU
 		{2DD1EE75-6D8D-4653-A800-0A24367F7F38}.Release|AnyCPU.ActiveCfg = Release|Any CPU
@@ -383,6 +389,7 @@ Global
 		{D48EE8D0-0A0A-4493-AEF5-DAF5F8CF86AD} = {864062D3-A415-4A6F-9324-5820237BA058}
 		{53EE4C57-1C03-405A-8243-8DA539546C88} = {04E3E11E-B47D-4599-8AFC-50515A95E715}
 		{9B42A5BB-74CB-46E2-BCE0-AF763A792551} = {04E3E11E-B47D-4599-8AFC-50515A95E715}
+		{645E1718-C8C4-4C23-8A49-5A37E4ECF7ED} = {04E3E11E-B47D-4599-8AFC-50515A95E715}
 		{2DD1EE75-6D8D-4653-A800-0A24367F7F38} = {CAB438D8-B0F5-4AF0-BEBD-9E2ADBD7B483}
 		{53E4ABF0-1085-45F9-B964-DCAE4B819998} = {CAB438D8-B0F5-4AF0-BEBD-9E2ADBD7B483}
 		{38C762AB-8FD1-44DE-9855-26AAE7129DC3} = {864062D3-A415-4A6F-9324-5820237BA058}

@@ -46,6 +46,7 @@ projects that use the Microsoft.Android.Runtimes framework in .NET 6+.
       BeforeTargets="GetFilesToPackage" >
     <PropertyGroup>
       <_RuntimeFlavorDirName Condition=" '$(AndroidRuntime)' == 'CoreCLR' ">$(_CLRRuntimeFlavorDirName)</_RuntimeFlavorDirName>
+      <_RuntimeFlavorDirName Condition=" '$(AndroidRuntime)' == 'NativeAOT' ">$(_NativeAotRuntimeFlavorDirName)</_RuntimeFlavorDirName>
       <_RuntimeFlavorDirName Condition=" '$(AndroidRuntime)' == 'Mono' Or '$(AndroidRuntime)' == '' ">$(_MonoRuntimeFlavorDirName)</_RuntimeFlavorDirName>
       <_ClangArch Condition=" '$(AndroidRID)' == 'android-arm64' ">aarch64</_ClangArch>
       <_ClangArch Condition=" '$(AndroidRID)' == 'android-arm' ">arm</_ClangArch>
@@ -102,6 +103,8 @@ projects that use the Microsoft.Android.Runtimes framework in .NET 6+.
     </ItemGroup>
 
     <ItemGroup Condition=" '$(AndroidRuntime)' == 'NativeAOT' ">
+      <NativeRuntimeAsset Condition=" Exists('$(NativeRuntimeOutputRootDir)$(_RuntimeFlavorDirName)\$(AndroidRID)\libnaot-android.debug-static-debug.a') " Include="$(NativeRuntimeOutputRootDir)$(_RuntimeFlavorDirName)\$(AndroidRID)\libnaot-android.debug-static-debug.a" />
+      <NativeRuntimeAsset Condition=" Exists('$(NativeRuntimeOutputRootDir)$(_RuntimeFlavorDirName)\$(AndroidRID)\libnaot-android.release-static-release.a') " Include="$(NativeRuntimeOutputRootDir)$(_RuntimeFlavorDirName)\$(AndroidRID)\libnaot-android.release-static-release.a" />
       <_AndroidRuntimePackAssemblies Include="$(_MonoAndroidNETOutputRoot)$(AndroidLatestStableApiLevel)\Microsoft.Android.Runtime.NativeAOT.dll" />
     </ItemGroup>
 

@@ -3,6 +3,8 @@
 using Android.Util;
 using System.Reflection;
 using System.Runtime.InteropServices;
+using System.Security.Cryptography;
+using System.Text;
 
 namespace NativeAOT;
 
@@ -27,5 +29,9 @@ protected override void OnCreate(Bundle? savedInstanceState)
         if (t) {
             throw new InvalidOperationException ("What happened?");
         }
+
+        // This tests loading and initializing JNI shared libraries
+        var hashData = new byte[32];
+        SHA256.HashData(Encoding.ASCII.GetBytes("Hello World"), hashData.AsSpan());
     }
 }
@@ -0,0 +1,28 @@
+#!/bin/bash -e
+CONFIG=Release
+APK="bin/${CONFIG}/net10.0-android/net.dot.hellonativeaot-Signed.apk"
+PACKAGE="net.dot.hellonativeaot"
+ACTIVITY="my.MainActivity"
+
+FAILED=no
+rm -rf bin obj
+../../dotnet-local.sh build -c ${CONFIG} -bl || FAILED=yes
+../../dotnet-local.sh msbuild -v:diag msbuild.binlog > msbuild.txt
+if [ "${FAILED}" == "yes" ]; then
+  echo Build failed
+  exit 1
+fi
+
+if [ -n "${1}" ]; then
+  exit 0
+fi
+
+adb uninstall "${PACKAGE}" || true
+adb install -r -d --no-streaming --no-fastdeploy "${APK}"
+#adb shell setprop debug.mono.log default,assembly,timing=bare
+adb logcat -G 128M
+adb logcat -c
+adb shell am start -S --user "0" -a "android.intent.action.MAIN" -c "android.intent.category.LAUNCHER" -n "${PACKAGE}/${ACTIVITY}" -W
+echo "Waiting for the app to start..."
+sleep 5
+adb logcat -d > log.txt
@@ -8,11 +8,15 @@ static partial class JavaInteropRuntime
 {
 	static JniRuntime? runtime;
 
+	[DllImport("xa-internal-api")]
+	static extern int XA_Host_NativeAOT_JNI_OnLoad (IntPtr vm, IntPtr reserved);
+
 	[UnmanagedCallersOnly (EntryPoint="JNI_OnLoad")]
 	static int JNI_OnLoad (IntPtr vm, IntPtr reserved)
 	{
 		try {
 			AndroidLog.Print (AndroidLogLevel.Info, "JavaInteropRuntime", "JNI_OnLoad()");
+			XA_Host_NativeAOT_JNI_OnLoad (vm, reserved);
 			LogcatTextWriter.Init ();
 			return (int) JniVersion.v1_6;
 		}
@@ -29,6 +33,9 @@ static void JNI_OnUnload (IntPtr vm, IntPtr reserved)
 		runtime?.Dispose ();
 	}
 
+	[DllImport("xa-internal-api")]
+	static extern void XA_Host_NativeAOT_OnInit ();
+
 	// symbol name from `$(IntermediateOutputPath)obj/Release/osx-arm64/h-classes/net_dot_jni_hello_JavaInteropRuntime.h`
 	[UnmanagedCallersOnly (EntryPoint="Java_net_dot_jni_nativeaot_JavaInteropRuntime_init")]
 	static void init (IntPtr jnienv, IntPtr klass, IntPtr classLoader)
@@ -38,12 +45,11 @@ static void init (IntPtr jnienv, IntPtr klass, IntPtr classLoader)
 			var settings    = new DiagnosticSettings ();
 			settings.AddDebugDotnetLog ();
 
-			var typeManager = new ManagedTypeManager ();
 			var options = new NativeAotRuntimeOptions {
 				EnvironmentPointer          = jnienv,
-				ClassLoader                 = new JniObjectReference (classLoader),
-				TypeManager                 = typeManager,
-				ValueManager                = new SimpleValueManager (),
+				ClassLoader                 = new JniObjectReference (classLoader, JniObjectReferenceType.Global),
+				TypeManager                 = new ManagedTypeManager (),
+				ValueManager                = ManagedValueManager.GetOrCreateInstance (),
 				UseMarshalMemberBuilder     = false,
 				JniGlobalReferenceLogWriter = settings.GrefLog,
 				JniLocalReferenceLogWriter  = settings.LrefLog,
@@ -52,6 +58,7 @@ static void init (IntPtr jnienv, IntPtr klass, IntPtr classLoader)
 
 			// Entry point into Mono.Android.dll
 			JNIEnvInit.InitializeJniRuntime (runtime);
+			XA_Host_NativeAOT_OnInit ();
 
 			transition  = new JniTransition (jnienv);
 
@@ -64,4 +71,4 @@ static void init (IntPtr jnienv, IntPtr klass, IntPtr classLoader)
 		}
 		transition.Dispose ();
 	}
-}
+}
@@ -61,8 +61,8 @@ static NativeAotRuntimeOptions CreateJreVM (NativeAotRuntimeOptions builder)
 			builder.TypeManager     ??= new ManagedTypeManager ();
 #endif  // NET
 
-			builder.ValueManager            ??= new SimpleValueManager ();
-			builder.ObjectReferenceManager  ??= new ManagedObjectReferenceManager (builder.JniGlobalReferenceLogWriter, builder.JniLocalReferenceLogWriter);
+			builder.ValueManager            ??= ManagedValueManager.GetOrCreateInstance();
+			builder.ObjectReferenceManager  ??= new Android.Runtime.AndroidObjectReferenceManager ();
 
 			if (builder.InvocationPointer != IntPtr.Zero || builder.EnvironmentPointer != IntPtr.Zero)
 				return builder;

@@ -102,7 +102,8 @@ public AndroidRuntimeOptions (IntPtr jnienv,
 		}
 	}
 
-	class AndroidObjectReferenceManager : JniRuntime.JniObjectReferenceManager {
+	// TODO: this shouldn't be public
+	public class AndroidObjectReferenceManager : JniRuntime.JniObjectReferenceManager {
 		public override int GlobalReferenceCount {
 			get {return RuntimeNativeMethods._monodroid_gref_get ();}
 		}
@@ -186,7 +187,7 @@ public override JniObjectReference CreateGlobalReference (JniObjectReference val
 			var from  = log ? new StringBuilder (new StackTrace (true).ToString ()) : null;
 			int gc 		= RuntimeNativeMethods._monodroid_gref_log_new (value.Handle, ctype, r.Handle, ntype, tname, tid, from, 1);
 			if (gc >= JNIEnvInit.gref_gc_threshold) {
-				Logger.Log (LogLevel.Info, "monodroid-gc", gc + " outstanding GREFs. Performing a full GC!");
+				Logger.Log (LogLevel.Debug, "monodroid-gc", gc + " outstanding GREFs. Performing a full GC!");
 				System.GC.Collect ();
 			}
 

@@ -82,6 +82,10 @@ static Type TypeGetType (string typeName) =>
 		internal static void InitializeJniRuntime (JniRuntime runtime)
 		{
 			androidRuntime = runtime;
+			gref_gc_threshold = RuntimeNativeMethods._monodroid_max_gref_get ();
+			if (gref_gc_threshold != int.MaxValue) {
+				gref_gc_threshold = checked((gref_gc_threshold * 9) / 10);
+			}
 			SetSynchronizationContext ();
 		}
 

@@ -8,6 +8,8 @@ This file contains the NativeAOT-specific MSBuild logic for .NET for Android.
 <Project>
 
   <UsingTask TaskName="Xamarin.Android.Tasks.SetNdkPathForIlc" AssemblyFile="$(_XamarinAndroidBuildTasksAssembly)" />
+  <UsingTask TaskName="Xamarin.Android.Tasks.GenerateNativeAotLibraryLoadAssemblerSources" AssemblyFile="$(_XamarinAndroidBuildTasksAssembly)" />
+  <UsingTask TaskName="Xamarin.Android.Tasks.GenerateNativeAotEnvironmentAssemblerSources" AssemblyFile="$(_XamarinAndroidBuildTasksAssembly)" />
 
   <!-- Default property values for NativeAOT -->
   <PropertyGroup>
@@ -93,6 +95,9 @@ This file contains the NativeAOT-specific MSBuild logic for .NET for Android.
     <ItemGroup>
       <!-- Android needs a proper soname property or it will refuse to load the library -->
       <LinkerArg Include="&quot;-Wl,-soname,lib$(TargetName)$(NativeBinaryExt)&quot;" />
+      <LinkerArg Include="-Wl,--error-unresolved-symbols" />
+      <LinkerArg Include="-Wl,--no-undefined" />
+
       <!-- Required for [UnmanagedCallersOnly] to work inside this assembly -->
       <UnmanagedEntryPointsAssembly Include="Microsoft.Android.Runtime.NativeAOT" />
       <!-- Give ILLink's output to ILC -->
@@ -110,7 +115,85 @@ This file contains the NativeAOT-specific MSBuild logic for .NET for Android.
       <ResolvedFileToPublish Include="$(_NdkSysrootDir)libc++_shared.so" RuntimeIdentifier="$(RuntimeIdentifier)" />
       <!-- Satellite assemblies -->
       <IlcSatelliteAssembly Include="$(_OuterIntermediateSatelliteAssembliesWithTargetPath)" />
+
+      <LinkerArg Include="@(RuntimePackAsset->WithMetadataValue('Filename', 'libnaot-android.$(Configuration.ToLower())-static-$(Configuration.ToLower())'))" />
+      <LinkerArg Include="$(_NdkSysrootDir)libc++_shared.so" />
+
+      <!-- Every p/invoke using the `xa-internal-api` "library" will be called directly -->
+      <DirectPInvoke Include="xa-internal-api" />
+    </ItemGroup>
+  </Target>
+
+  <Target Name="_PrepareNativeAotAndroidAppInputs">
+    <ItemGroup>
+      <_PrivateBuildTargetAbi Condition=" '$(RuntimeIdentifier)' == 'android-arm64' " Include="arm64-v8a" />
+      <_PrivateBuildTargetAbi Condition=" '$(RuntimeIdentifier)' == 'android-x64' " Include="x86_64" />
     </ItemGroup>
+
+    <PrepareAbiItems
+        BuildTargetAbis="@(_PrivateBuildTargetAbi)"
+        NativeSourcesDir="$(_NativeAssemblySourceDir)"
+        Debug="$(AndroidIncludeDebugSymbols)"
+        Mode="jni_init">
+      <Output TaskParameter="AssemblySources" ItemName="_PrivateJniInitFuncsAssemblySource" />
+    </PrepareAbiItems>
+
+    <PrepareAbiItems
+        BuildTargetAbis="@(_PrivateBuildTargetAbi)"
+        NativeSourcesDir="$(_NativeAssemblySourceDir)"
+        Debug="$(AndroidIncludeDebugSymbols)"
+        Mode="environment">
+      <Output TaskParameter="AssemblySources" ItemName="_PrivateEnvironmentAssemblySource" />
+    </PrepareAbiItems>
+
+    <ItemGroup>
+      <_PrivateJniInitFuncsNativeObjectFile Include="@(_PrivateJniInitFuncsAssemblySource->'$([System.IO.Path]::ChangeExtension('%(Identity)', '.o'))')">
+        <abi>%(_PrivateJniInitFuncsAssemblySource.abi)</abi>
+      </_PrivateJniInitFuncsNativeObjectFile>
+
+      <_PrivateEnvironmentNativeObjectFile Include="@(_PrivateEnvironmentAssemblySource->'$([System.IO.Path]::ChangeExtension('%(Identity)', '.o'))')">
+        <abi>%(_PrivateEnvironmentAssemblySource.abi)</abi>
+      </_PrivateEnvironmentNativeObjectFile>
+
+      <_PrivateAndroidNaotResolvedAssemblyFiles Include="@(ResolvedFileToPublish->Distinct())" Condition=" '%(ResolvedFileToPublish.Extension)' == '.dll' " />
+    </ItemGroup>
+  </Target>
+
+  <Target
+      Name="_GenerateNativeAotAndroidAppAssemblerSources"
+      DependsOnTargets="_GenerateEnvironmentFiles;_PrepareNativeAotAndroidAppInputs"
+      Inputs="@(_PrivateAndroidNaotResolvedAssemblyFiles);@(AndroidEnvironment);@(LibraryEnvironments)"
+      Outputs="@(_PrivateJniInitFuncsAssemblySource);@(_PrivateJniInitFuncsNativeObjectFile);@(_PrivateEnvironmentAssemblySource);@(_PrivateEnvironmentNativeObjectFile)">
+    <GenerateNativeAotLibraryLoadAssemblerSources
+        ResolvedAssemblies="@(_PrivateAndroidNaotResolvedAssemblyFiles)"
+        CustomJniInitFunctions="@(AndroidStaticJniInitFunction)"
+        OutputSources="@(_PrivateJniInitFuncsAssemblySource)" />
+
+    <GenerateNativeAotEnvironmentAssemblerSources
+        Debug="$(AndroidIncludeDebugSymbols)"
+        Environments="@(AndroidEnvironment);@(LibraryEnvironments)"
+        HttpClientHandlerType="$(AndroidHttpClientHandlerType)"
+        OutputSources="@(_PrivateEnvironmentAssemblySource)"
+        RID="$(RuntimeIdentifier)" />
+
+    <CompileNativeAssembly
+        Sources="@(_PrivateJniInitFuncsAssemblySource);@(_PrivateEnvironmentAssemblySource)"
+        DebugBuild="$(AndroidIncludeDebugSymbols)"
+        WorkingDirectory="$(_NativeAssemblySourceDir)"
+        AndroidBinUtilsDirectory="$(AndroidBinUtilsDirectory)" />
+
+    <ItemGroup>
+      <LinkerArg Include="@(_PrivateJniInitFuncsNativeObjectFile)" />
+      <LinkerArg Include="@(_PrivateEnvironmentNativeObjectFile)" />
+    </ItemGroup>
+  </Target>
+
+  <!-- Make sure we have a chance to generate our application-specific static library before linking
+       takes place. We must run after `IlcCompile`, which is a dependency of `LinkNative`  -->
+  <Target
+      Name="_GenerateNativeAotAndroidAppLibrary"
+      AfterTargets="IlcCompile"
+      DependsOnTargets="_GenerateNativeAotAndroidAppAssemblerSources">
   </Target>
 
   <Target Name="_AndroidFixNativeLibraryFileName" AfterTargets="ComputeFilesToPublish">

@@ -91,32 +91,6 @@ public override bool RunTask ()
 			return !Log.HasLoggedErrors;
 		}
 
-		XAAssemblyResolver MakeResolver (bool useMarshalMethods, AndroidTargetArch targetArch, Dictionary<string, ITaskItem> assemblies)
-		{
-			var readerParams = new ReaderParameters ();
-			if (useMarshalMethods) {
-				readerParams.ReadWrite = true;
-				readerParams.InMemory = true;
-			}
-
-			var res = new XAAssemblyResolver (targetArch, Log, loadDebugSymbols: true, loadReaderParameters: readerParams);
-			var uniqueDirs = new HashSet<string> (StringComparer.OrdinalIgnoreCase);
-
-			Log.LogDebugMessage ($"Adding search directories to new architecture {targetArch} resolver:");
-			foreach (var kvp in assemblies) {
-				string assemblyDir = Path.GetDirectoryName (kvp.Value.ItemSpec);
-				if (uniqueDirs.Contains (assemblyDir)) {
-					continue;
-				}
-
-				uniqueDirs.Add (assemblyDir);
-				res.SearchDirectories.Add (assemblyDir);
-				Log.LogDebugMessage ($"  {assemblyDir}");
-			}
-
-			return res;
-		}
-
 		void Run (bool useMarshalMethods)
 		{
 			PackageNamingPolicy pnp;
@@ -253,7 +227,7 @@ internal static Dictionary<string, ITaskItem> MaybeGetArchAssemblies (Dictionary
 
 		(bool success, NativeCodeGenState? stubsState) GenerateJavaSourcesAndMaybeClassifyMarshalMethods (AndroidTargetArch arch, Dictionary<string, ITaskItem> assemblies, Dictionary<string, ITaskItem> userAssemblies, bool useMarshalMethods, bool generateJavaCode)
 		{
-			XAAssemblyResolver resolver = MakeResolver (useMarshalMethods, arch, assemblies);
+			XAAssemblyResolver resolver = MonoAndroidHelper.MakeResolver (Log, useMarshalMethods, arch, assemblies);
 			var tdCache = new TypeDefinitionCache ();
 			(List<TypeDefinition> allJavaTypes, List<TypeDefinition> javaTypesForJCW) = ScanForJavaTypes (resolver, tdCache, assemblies, userAssemblies, useMarshalMethods);
 			var jcwContext = new JCWGeneratorContext (arch, resolver, assemblies.Values, javaTypesForJCW, tdCache);