From ba0a61f422dda11363e1c0befac6815aee7a94e2 Mon Sep 17 00:00:00 2001
From: Marek Habersack <grendel@twistedcode.net>
Date: Wed, 2 Oct 2024 10:17:41 +0200
Subject: [PATCH] Add test for marshal methods hang (#9352)

Context: https://github.com/dotnet/android/pull/9343
Context: https://github.com/dotnet/android/issues/8253#issuecomment-2380714158

Test is based on the original repro from https://github.com/filipnavara/mm-deadlock-repro/
---
 .../Tests/InstallAndRunTests.cs               |   5 -
 .../Tests/MarshalMethodsGCHangTests.cs        | 115 ++++++++++++++++++
 2 files changed, 115 insertions(+), 5 deletions(-)
 create mode 100644 tests/MSBuildDeviceIntegration/Tests/MarshalMethodsGCHangTests.cs

diff --git a/tests/MSBuildDeviceIntegration/Tests/InstallAndRunTests.cs b/tests/MSBuildDeviceIntegration/Tests/InstallAndRunTests.cs
index 0ab31c828e3..c6516e8f7f1 100644
--- a/tests/MSBuildDeviceIntegration/Tests/InstallAndRunTests.cs
+++ b/tests/MSBuildDeviceIntegration/Tests/InstallAndRunTests.cs
@@ -30,11 +30,6 @@ public void Teardown ()
 		[Test]
 		public void NativeAssemblyCacheWithSatelliteAssemblies ([Values (true, false)] bool enableMarshalMethods)
 		{
-			// TODO: enable when marshal methods are fixed
-			if (enableMarshalMethods) {
-				Assert.Ignore ("Test is skipped when marshal methods are enabled, pending fixes to MM for .NET9");
-			}
-
 			var path = Path.Combine ("temp", TestName);
 			var lib = new XamarinAndroidLibraryProject {
 				ProjectName = "Localization",
diff --git a/tests/MSBuildDeviceIntegration/Tests/MarshalMethodsGCHangTests.cs b/tests/MSBuildDeviceIntegration/Tests/MarshalMethodsGCHangTests.cs
new file mode 100644
index 00000000000..cd24f8028ac
--- /dev/null
+++ b/tests/MSBuildDeviceIntegration/Tests/MarshalMethodsGCHangTests.cs
@@ -0,0 +1,115 @@
+using System;
+using NUnit.Framework;
+using Xamarin.ProjectTools;
+using System.IO;
+using System.Linq;
+using Microsoft.Build.Framework;
+using System.Text;
+using System.Xml.Linq;
+using System.Collections.Generic;
+
+namespace Xamarin.Android.Build.Tests;
+
+[TestFixture]
+[Category ("UsesDevice")]
+[Category ("MayHang")]
+public class MarshalMethodsGCHangTests : DeviceTest
+{
+	static readonly string MarshalMethodsAppRuns_PermissionManifest = @"<?xml version=""1.0"" encoding=""utf-8""?>
+<manifest xmlns:android=""http://schemas.android.com/apk/res/android"" android:versionCode=""1"" android:versionName=""1.0"" package=""{0}"">
+        <uses-sdk />
+        <application android:label=""{0}"">
+        </application>
+        <uses-permission android:name=""android.permission.INTERNET"" />
+</manifest>";
+
+	static readonly string MarshalMethodsAppRuns_MainActivity = @"using Android.Media;
+
+namespace marshal2;
+
+[Activity (Label = ""@string/app_name"", MainLauncher = true)]
+public class MainActivity : Activity
+{
+	protected override void OnCreate (Bundle? savedInstanceState)
+	{
+		base.OnCreate (savedInstanceState);
+		SetContentView (Resource.Layout.Main);
+	}
+
+	protected override void OnStart ()
+	{
+		base.OnStart ();
+
+		try {
+			var mp = new MediaPlayer ();
+			mp.SetDataSource (new StreamMediaDataSource (new MemoryStream (new byte[65536])));
+			mp.Prepare ();
+		} catch (Java.IO.IOException) {
+			GC.Collect ();
+		}
+	}
+
+	class StreamMediaDataSource (System.IO.Stream data) : MediaDataSource
+	{
+		public override long Size => data.Length;
+
+		public override int ReadAt (long position, byte[]? buffer, int offset, int size)
+		{
+			try {
+				Console.WriteLine ($""XXX:START StreamMediaDataSource.ReadAt {position} {buffer} {buffer?.Length ?? 0} {offset} {size}"");
+
+				// Allocate enough to trigger GC
+				for (int i = 0; i < 1000; i++) {
+					_ = new byte[8192];
+				}
+
+				if (data.CanSeek) {
+					data.Seek (position, SeekOrigin.Begin);
+				}
+				return data.Read (buffer ?? [], offset, size);
+			} finally {
+				Console.WriteLine ($""XXX:END //StreamMediaDataSource.ReadAt {position} {buffer} {buffer?.Length ?? 0} {offset} {size}"");
+			}
+		}
+
+		public override void Close ()
+		{
+			data.Dispose ();
+			data = System.IO.Stream.Null;
+		}
+	}
+}
+";
+
+	// All Tests here require the emulator to be started with -writable-system
+	[Test]
+	public void MarshalMethodsAppRuns ()
+	{
+		var proj = new XamarinAndroidApplicationProject (packageName: "marshal2") {
+			IsRelease = true,
+			EnableMarshalMethods = true,
+			TargetFramework = "net9.0-android",
+			SupportedOSPlatformVersion = "23",
+			TrimModeRelease = TrimMode.Full,
+			ProjectName = "marshal2",
+		};
+
+		proj.SetAndroidSupportedAbis (DeviceAbi);
+		proj.AndroidManifest = String.Format (MarshalMethodsAppRuns_PermissionManifest, proj.PackageName);
+		proj.MainActivity = MarshalMethodsAppRuns_MainActivity;
+		proj.SetDefaultTargetDevice ();
+
+		using var apkBuilder = CreateApkBuilder (Path.Combine ("temp", TestName));
+		Assert.True (apkBuilder.Install (proj), "Project should have installed.");
+		RunProjectAndAssert (proj, apkBuilder);
+
+		const string expectedLogcatOutput = "XXX:END //StreamMediaDataSource.ReadAt";
+		Assert.IsTrue (
+			MonitorAdbLogcat (
+				InstallAndRunTests.CreateLineChecker (expectedLogcatOutput),
+				logcatFilePath: Path.Combine (Root, apkBuilder.ProjectDirectory, "startup-logcat.log"), timeout: 60
+			),
+			$"Output did not contain {expectedLogcatOutput}!"
+		);
+	}
+}