[tests] Isolate JNI reference leak tests

.github/skills/tests/references/test-catalog.md

@@ -123,6 +123,7 @@ Device: **Yes**
 | Test Area | Project | Notes |
 |-----------|---------|-------|
 | **runtime** (all) | `tests/Mono.Android-Tests/Mono.Android-Tests/Mono.Android.NET-Tests.csproj` | Core runtime tests |
+| **JNI reference leaks** | `tests/JniReferenceLeakTests/JniReferenceLeakTests.csproj` | Dedicated serial NUnit/MTP app for JNI reference and peer leak checks |
 | **networking** | Same project — tests in `Xamarin.Android.Net/` and `System.Net/` | `AndroidMessageHandlerTests`, `AndroidMessageHandlerIntegrationTests` |
 | **java interop (on-device)** | Same project — tests in `Java.Interop/` | `JnienvTest`, `JavaListTest` |
 | **android app** | Same project — tests in `Android.App/` | `Application`, `Activity` tests |
@@ -154,6 +155,15 @@ Command:
 
 Results are `.trx` files under `bin/TestDebug/TestResults/` and are published as VSTest results in CI. Always pass the same configuration and MSBuild properties to the install and `dotnet test --no-build` commands (for example, `-c Release -p:UseMonoRuntime=false`).
 
+For the dedicated JNI reference leak tests:
+```bash
+./dotnet-local.sh build -t:Install -c Debug tests/JniReferenceLeakTests/JniReferenceLeakTests.csproj
+(
+  cd tests/JniReferenceLeakTests
+  ../../dotnet-local.sh test JniReferenceLeakTests.csproj --no-build -c Debug --report-trx --results-directory ../../bin/TestDebug/TestResults
+)
+```
+
 For `Xamarin.Android.JcwGen-Tests`, use the same pattern from `tests/CodeGen-Binding/Xamarin.Android.JcwGen-Tests/`:
 ```bash
 ./dotnet-local.sh build -t:Install -c Debug tests/CodeGen-Binding/Xamarin.Android.JcwGen-Tests/Xamarin.Android.JcwGen-Tests.csproj

Xamarin.Android-Tests.slnx

@@ -27,6 +27,7 @@
     <Project Path="samples/HelloWorld/HelloWorld/HelloWorld.DotNet.csproj" />
   </Folder>
   <Folder Name="/tests/">
+    <Project Path="tests/JniReferenceLeakTests/JniReferenceLeakTests.csproj" />
     <Project Path="tests/StartupHook/StartupHook.csproj" />
   </Folder>
   <Folder Name="/tests/Mono.Android-Tests/" />

build-tools/automation/azure-pipelines-nightly.yaml

@@ -145,6 +145,30 @@ stages:
         artifactSource: bin/Test$(XA.Build.Configuration)/$(DotNetTargetFramework)-android/Mono.Android.NET_Tests-Signed.aab
         artifactFolder: Mono.Android-$(XA.Build.Configuration)-$(avdApiLevel)
 
+    - template: /build-tools/automation/yaml-templates/apk-instrumentation.yaml
+      parameters:
+        buildConfiguration: $(XA.Build.Configuration)
+        configuration: Debug
+        testName: JniReferenceLeakTests-$(avdApiLevel)
+        project: tests/JniReferenceLeakTests/JniReferenceLeakTests.csproj
+        extraBuildArgs: -p:UseMonoRuntime=false -p:TestAvdApiLevel=$(avdApiLevel) -p:TestAvdAbi=$(avdAbi) -p:TestAvdType=$(avdType)
+        artifactSource: bin/TestDebug/$(DotNetTargetFramework)-android/net.dot.jni.referenceleaktests-Signed.apk
+        artifactFolder: JniReferenceLeakTests-$(avdApiLevel)
+
+    # Also run in Release so full trimming (TrimMode=full, Release-only) is
+    # exercised - trimming can remove code paths that keep peers/references
+    # alive, exactly the regressions this app exists to catch. Kept in nightly
+    # (not PR package-tests) to avoid adding an emulator run to every PR.
+    - template: /build-tools/automation/yaml-templates/apk-instrumentation.yaml
+      parameters:
+        buildConfiguration: $(XA.Build.Configuration)
+        configuration: Release
+        testName: JniReferenceLeakTests-Release-$(avdApiLevel)
+        project: tests/JniReferenceLeakTests/JniReferenceLeakTests.csproj
+        extraBuildArgs: -p:UseMonoRuntime=false -p:TestAvdApiLevel=$(avdApiLevel) -p:TestAvdAbi=$(avdAbi) -p:TestAvdType=$(avdType)
+        artifactSource: bin/TestRelease/$(DotNetTargetFramework)-android/net.dot.jni.referenceleaktests-Signed.apk
+        artifactFolder: JniReferenceLeakTests-Release-$(avdApiLevel)
+
     - template: /build-tools/automation/yaml-templates/upload-results.yaml
       parameters:
         configuration: $(XA.Build.Configuration)

build-tools/automation/yaml-templates/stage-package-tests.yaml

@@ -140,6 +140,34 @@ stages:
 
     - template: /build-tools/automation/yaml-templates/start-stop-emulator.yaml
 
+    - template: /build-tools/automation/yaml-templates/apk-instrumentation.yaml
+      parameters:
+        buildConfiguration: $(XA.Build.Configuration)
+        configuration: Debug
+        testName: JniReferenceLeakTests-CoreCLR
+        project: tests/JniReferenceLeakTests/JniReferenceLeakTests.csproj
+        extraBuildArgs: -p:UseMonoRuntime=false
+        artifactSource: bin/TestDebug/$(DotNetTargetFramework)-android/net.dot.jni.referenceleaktests-Signed.apk
+        artifactFolder: $(DotNetTargetFramework)-JniReferenceLeakTests-CoreCLR
+
+    - template: /build-tools/automation/yaml-templates/apk-instrumentation.yaml
+      parameters:
+        configuration: $(XA.Build.Configuration)
+        testName: JniReferenceLeakTests-CoreCLRTrimmable
+        project: tests/JniReferenceLeakTests/JniReferenceLeakTests.csproj
+        extraBuildArgs: -p:_AndroidTypeMapImplementation=trimmable -p:UseMonoRuntime=false
+        artifactSource: bin/Test$(XA.Build.Configuration)/$(DotNetTargetFramework)-android/net.dot.jni.referenceleaktests-Signed.apk
+        artifactFolder: $(DotNetTargetFramework)-JniReferenceLeakTests-CoreCLRTrimmable
+
+    - template: /build-tools/automation/yaml-templates/apk-instrumentation.yaml
+      parameters:
+        configuration: $(XA.Build.Configuration)
+        testName: JniReferenceLeakTests-NativeAOT
+        project: tests/JniReferenceLeakTests/JniReferenceLeakTests.csproj
+        extraBuildArgs: -p:PublishAot=true
+        artifactSource: bin/Test$(XA.Build.Configuration)/$(DotNetTargetFramework)-android/net.dot.jni.referenceleaktests-Signed.apk
+        artifactFolder: $(DotNetTargetFramework)-JniReferenceLeakTests-NativeAOT
+
     - template: /build-tools/automation/yaml-templates/apk-instrumentation.yaml
       parameters:
         configuration: $(XA.Build.Configuration)

external/Java.Interop/tests/Java.Interop-Tests/Java.Interop/JavaArrayContract.cs

@@ -10,6 +10,7 @@ namespace Java.InteropTests
 {
 	public abstract class JavaArrayContract<T> : ListContract<T>
 	{
+#if !__ANDROID__
 		int lrefStartCount;
 
 		[OneTimeSetUp]
@@ -24,6 +25,7 @@ public void EndArrayTests ()
 			int lref    = JniEnvironment.LocalReferenceCount;
 			Assert.AreEqual (lrefStartCount, lref, "JNI local references");
 		}
+#endif // !__ANDROID__
 
 		[Test]
 		public void ToArray ()
@@ -41,4 +43,3 @@ public void ToArray ()
 		}
 	}
 }
-

external/Java.Interop/tests/Java.Interop-Tests/Java.Interop/JavaObjectArrayTest.cs

@@ -157,6 +157,7 @@ public class JavaObjectArray_object_ContractTest : JavaObjectArrayContractTest<o
 		protected override object CreateValueA () {return a;}
 		protected override object CreateValueB () {return 42;}
 
+#if !__ANDROID__
 		int grefStartCount;
 
 		[OneTimeSetUp]
@@ -176,6 +177,7 @@ public void EndCheckGlobalRefCount ()
 					string.Format ("JNI global references: grefStartCount={0}; gref={1}", grefStartCount, gref));
 			JniEnvironment.Runtime.ValueManager.CollectPeers ();
 		}
+#endif // !__ANDROID__
 
 		[Test]
 		public void ObjectArrayType ()

external/Java.Interop/tests/Java.Interop-Tests/Java.Interop/JavaObjectTest.cs

@@ -43,6 +43,7 @@ public void JavaReferencedInstanceSurvivesCollection ()
 		}
 #endif  // !NO_GC_BRIDGE_SUPPORT
 
+#if !__ANDROID__
 		[Test]
 		[Ignore ("Frequently failing: https://github.com/dotnet/android/issues/12031")]
 		public void UnregisterFromRuntime ()
@@ -63,6 +64,7 @@ public void UnregisterFromRuntime ()
 			JniObjectReference.Dispose (ref l);
 			Assert.Throws<ObjectDisposedException> (() => o.UnregisterFromRuntime ());
 		}
+#endif // !__ANDROID__
 
 		[Test]
 		public void RegisterWithVM_PermitsAliases ()

external/Java.Interop/tests/Java.Interop-Tests/Java.Interop/JniEnvironmentTests.cs

@@ -55,6 +55,7 @@ public unsafe void Handles_NewReturnToJniRef ()
 			}
 		}
 
+#if !__ANDROID__
 		[Test]
 		public void References_CreatedReference_InvalidRef ()
 		{
@@ -142,6 +143,6 @@ public void References_CreatedReference_GlobalRef ()
 				GetDeleteRefFunc ("java_interop_jnienv_delete_global_ref")?.Invoke (JniEnvironment.EnvironmentPointer, o.Handle);
 			}
 		}
+#endif // !__ANDROID__
 	}
 }
-

external/Java.Interop/tests/Java.Interop-Tests/Java.Interop/JniRuntimeJniValueManagerContract.cs

@@ -61,75 +61,51 @@ public void AddPeer ()
 		{
 		}
 
-		int GetSurfacedPeersCount ()
+		int GetSurfacedPeerCount (IJavaPeerable peer)
 		{
-			return valueManager.GetSurfacedPeers ().Count;
+			return valueManager.GetSurfacedPeers ().Count (candidate => {
+				return candidate.SurfacedPeer.TryGetTarget (out var target) && object.ReferenceEquals (target, peer);
+			});
 		}
 
 		[Test]
 		public void AddPeer_NoDuplicates ()
 		{
-			int startPeerCount  = GetSurfacedPeersCount ();
 			using (var v = new MyDisposableObject ()) {
 				// MyDisposableObject ctor implicitly calls AddPeer();
-				Assert.AreEqual (startPeerCount + 1, GetSurfacedPeersCount (), DumpPeers ());
+				Assert.AreEqual (1, GetSurfacedPeerCount (v), DumpPeers ());
 				valueManager.AddPeer (v);
-				Assert.AreEqual (startPeerCount + 1, GetSurfacedPeersCount (), DumpPeers ());
+				Assert.AreEqual (1, GetSurfacedPeerCount (v), DumpPeers ());
 			}
 		}
 
 		[Test]
 		public void ConstructPeer_ImplicitViaBindingConstructor_PeerIsInSurfacedPeers ()
 		{
-			int startPeerCount  = GetSurfacedPeersCount ();
-
 			var g               = new GetThis ();
-			var surfaced        = valueManager.GetSurfacedPeers ();
-			Assert.AreEqual (startPeerCount + 1, surfaced.Count);
-
-			var found           = false;
-			foreach (var pr in surfaced) {
-				if (!pr.SurfacedPeer.TryGetTarget (out var p))
-					continue;
-				if (object.ReferenceEquals (g, p)) {
-					found = true;
-				}
-			}
-			Assert.IsTrue (found);
+			Assert.AreEqual (1, GetSurfacedPeerCount (g), DumpPeers ());
 
 			var localRef        = g.PeerReference.NewLocalRef ();
 			g.Dispose ();
-			Assert.AreEqual (startPeerCount, GetSurfacedPeersCount ());
+			Assert.AreEqual (0, GetSurfacedPeerCount (g));
 			Assert.IsNull (valueManager.PeekPeer (localRef));
 			JniObjectReference.Dispose (ref localRef);
 		}
 
 		[Test]
 		public void ConstructPeer_ImplicitViaBindingMethod_PeerIsInSurfacedPeers ()
 		{
-			int startPeerCount  = GetSurfacedPeersCount ();
-
 			var g               = new GetThis ();
-			var surfaced        = valueManager.GetSurfacedPeers ();
-			Assert.AreEqual (startPeerCount + 1, surfaced.Count);
-
-			var found           = false;
-			foreach (var pr in surfaced) {
-				if (!pr.SurfacedPeer.TryGetTarget (out var p))
-					continue;
-				if (object.ReferenceEquals (g, p)) {
-					found = true;
-				}
-			}
-			Assert.IsTrue (found);
+			Assert.AreEqual (1, GetSurfacedPeerCount (g), DumpPeers ());
 
 			var localRef        = g.PeerReference.NewLocalRef ();
 			g.Dispose ();
-			Assert.AreEqual (startPeerCount, GetSurfacedPeersCount ());
+			Assert.AreEqual (0, GetSurfacedPeerCount (g));
 			Assert.IsNull (valueManager.PeekPeer (localRef));
 			JniObjectReference.Dispose (ref localRef);
 		}
 
+#if !__ANDROID__
 		// https://github.com/dotnet/android/issues/11101
 		[Test]
 		public void ConstructPeer_CalledMultipleTimes_ShouldNotLeakGlobalRefs ()
@@ -169,6 +145,7 @@ public void ConstructPeer_CalledMultipleTimes_ShouldNotLeakGlobalRefs ()
 				}
 			}
 		}
+#endif // !__ANDROID__
 
 
 		[Test]

external/Java.Interop/tests/Java.Interop-Tests/Java.Interop/JniTypeUtf8Test.cs

@@ -90,8 +90,8 @@ public void TryFindClass_Utf8 ()
 			Assert.IsFalse (notFound.IsValid);
 		}
 
+#if !__ANDROID__
 		[Test]
-		[Ignore ("Frequently failing: https://github.com/dotnet/android/issues/12031")]
 		public void TryFindClass_Utf8_DoesNotLeakGlobalRefs ()
 		{
 			int grefsBefore = JniEnvironment.Runtime.GlobalReferenceCount;
@@ -110,6 +110,7 @@ public void TryFindClass_String_DoesNotLeakGlobalRefs ()
 			Assert.AreEqual (grefsBefore, grefsAfter,
 				"TryFindClass for non-existent classes should not leak global references");
 		}
+#endif // !__ANDROID__
 
 		[Test]
 		public void GetMethodID_Utf8_MatchesStringOverload ()

src/Mono.Android/Android.Runtime/JNIEnv.cs

@@ -384,7 +384,7 @@ public static void EnsureLocalCapacity (int capacity)
 
 		internal static void DeleteRef (IntPtr handle, JniHandleOwnership transfer)
 		{
-			switch (transfer) {
+			switch (transfer & ~JniHandleOwnership.DoNotRegister) {
 			case JniHandleOwnership.DoNotTransfer:
 				break;
 			case JniHandleOwnership.TransferLocalRef:

tests/CodeGen-Binding/Xamarin.Android.JcwGen-Tests/BindingTests.cs

@@ -101,16 +101,12 @@ public void JavaSideActivation ()
 				// To ensure that CallMethodFromCtor.class_ref is initialized
 			}
 			using (var c = Java.Lang.Class.FromType (typeof (ConstructorTest))) {
-				int initGref = Java.Interop.Runtime.GlobalReferenceCount;
 				using (var j = Com.Xamarin.Android.CallMethodFromCtor.NewInstance (c)) {
 					var instance = j.JavaCast<ConstructorTest>();
 					Assert.AreSame (j, instance);
 					Assert.IsTrue (instance.DefaultConstructorInvoked);
 					Assert.IsTrue (instance.ActivationConstructorInvoked);
 				}
-				int finiGref = Java.Interop.Runtime.GlobalReferenceCount;
-				Assert.AreEqual (initGref, finiGref,
-						string.Format ("Initial grefc={0}; final gref={1}; No GREFs should be lost!", initGref, finiGref));
 			}
 		}
 
@@ -391,4 +387,3 @@ public class B : Java.Lang.Object {
 		}
 	}
 }
-

tests/JniReferenceLeakTests/AndroidManifest.xml

@@ -0,0 +1,6 @@
+<?xml version="1.0" encoding="utf-8"?>
+<manifest xmlns:android="http://schemas.android.com/apk/res/android">
+  <application android:label="JniReferenceLeakTests">
+  </application>
+  <uses-permission android:name="android.permission.INTERNET" />
+</manifest>