Add EventPipe interop instrumentation for wrapper lifecycle and GC-bridge reachability

external/Java.Interop/Documentation/EventPipeInteropEvents.md

@@ -0,0 +1,42 @@
+# Java.Interop EventPipe interop events
+
+The .NET ↔ Java interop layer emits EventPipe events through a single provider:
+
+- **Provider name:** `Java.Interop`
+
+## Event catalog
+
+| Event ID | Event name | Meaning |
+|---|---|---|
+| 1 | `DotNetWrapperCreated` | A managed wrapper for a Java object was created. |
+| 2 | `JavaWrapperCreated` | A Java wrapper for a managed object was created. |
+| 3 | `DotNetWrapperReleasedJavaReference` | A managed wrapper released its Java reference. |
+| 4 | `JavaWrapperReleasedDotNetReference` | A Java wrapper released its managed reference. |
+| 5 | `DotNetObjectOnlyReachableFromJava` | A managed object is only reachable from Java during bridge processing. |
+| 6 | `JavaObjectOnlyReachableFromDotNet` | A Java object is only reachable from .NET during bridge processing. |
+
+## Payload schema
+
+All events contain:
+
+- `managedType` (`string`)
+- `javaType` (`string`)
+- `jniIdentityHashCode` (`int`)
+- `managedObjectHashCode` (`int`)
+- `runtimeMode` (`string`)
+
+Reachability events (`5`, `6`) additionally contain:
+
+- `componentIndex` (`int`)
+- `contextIndex` (`int`)
+- `contextPointer` (`long`)
+
+## Collecting events
+
+Use `dotnet-trace` to capture the provider:
+
+```bash
+dotnet-trace collect --process-id <pid> --providers Java.Interop:0x3:4
+```
+
+`0x3` enables both wrapper lifecycle and reachability keywords, and `4` enables informational-level events.

external/Java.Interop/src/Java.Interop/Java.Interop/InteropEventSource.cs

@@ -0,0 +1,172 @@
+#nullable enable
+
+using System.Diagnostics.Tracing;
+
+namespace Java.Interop
+{
+	public static class InteropEventSource
+	{
+		internal const string ProviderName = "Java.Interop";
+		const string UnknownValue = "Unknown";
+
+		static readonly InteropEventSourceImplementation source = new InteropEventSourceImplementation ();
+
+		public static bool IsEnabled ()
+		{
+			return source.IsEnabled ();
+		}
+
+		public static void DotNetWrapperCreated (
+				string? managedType,
+				string? javaType,
+				int jniIdentityHashCode,
+				int managedObjectHashCode,
+				string? runtimeMode)
+		{
+			source.DotNetWrapperCreated (
+				GetPayloadValue (managedType),
+				GetPayloadValue (javaType),
+				jniIdentityHashCode,
+				managedObjectHashCode,
+				GetPayloadValue (runtimeMode));
+		}
+
+		public static void JavaWrapperCreated (
+				string? managedType,
+				string? javaType,
+				int jniIdentityHashCode,
+				int managedObjectHashCode,
+				string? runtimeMode)
+		{
+			source.JavaWrapperCreated (
+				GetPayloadValue (managedType),
+				GetPayloadValue (javaType),
+				jniIdentityHashCode,
+				managedObjectHashCode,
+				GetPayloadValue (runtimeMode));
+		}
+
+		public static void DotNetWrapperReleasedJavaReference (
+				string? managedType,
+				string? javaType,
+				int jniIdentityHashCode,
+				int managedObjectHashCode,
+				string? runtimeMode)
+		{
+			source.DotNetWrapperReleasedJavaReference (
+				GetPayloadValue (managedType),
+				GetPayloadValue (javaType),
+				jniIdentityHashCode,
+				managedObjectHashCode,
+				GetPayloadValue (runtimeMode));
+		}
+
+		public static void JavaWrapperReleasedDotNetReference (
+				string? managedType,
+				string? javaType,
+				int jniIdentityHashCode,
+				int managedObjectHashCode,
+				string? runtimeMode)
+		{
+			source.JavaWrapperReleasedDotNetReference (
+				GetPayloadValue (managedType),
+				GetPayloadValue (javaType),
+				jniIdentityHashCode,
+				managedObjectHashCode,
+				GetPayloadValue (runtimeMode));
+		}
+
+		public static void DotNetObjectOnlyReachableFromJava (
+				string? managedType,
+				string? javaType,
+				int jniIdentityHashCode,
+				int managedObjectHashCode,
+				string? runtimeMode,
+				int componentIndex,
+				int contextIndex,
+				long contextPointer)
+		{
+			source.DotNetObjectOnlyReachableFromJava (
+				GetPayloadValue (managedType),
+				GetPayloadValue (javaType),
+				jniIdentityHashCode,
+				managedObjectHashCode,
+				GetPayloadValue (runtimeMode),
+				componentIndex,
+				contextIndex,
+				contextPointer);
+		}
+
+		public static void JavaObjectOnlyReachableFromDotNet (
+				string? managedType,
+				string? javaType,
+				int jniIdentityHashCode,
+				int managedObjectHashCode,
+				string? runtimeMode,
+				int componentIndex,
+				int contextIndex,
+				long contextPointer)
+		{
+			source.JavaObjectOnlyReachableFromDotNet (
+				GetPayloadValue (managedType),
+				GetPayloadValue (javaType),
+				jniIdentityHashCode,
+				managedObjectHashCode,
+				GetPayloadValue (runtimeMode),
+				componentIndex,
+				contextIndex,
+				contextPointer);
+		}
+
+		static string GetPayloadValue (string? value)
+		{
+			return value ?? UnknownValue;
+		}
+
+		[EventSource (Name = ProviderName)]
+		sealed class InteropEventSourceImplementation : EventSource
+		{
+			public static class Keywords
+			{
+				public const EventKeywords WrapperLifecycle = (EventKeywords) 0x1;
+				public const EventKeywords Reachability = (EventKeywords) 0x2;
+			}
+
+			[Event (1, Level = EventLevel.Informational, Keywords = Keywords.WrapperLifecycle)]
+			public void DotNetWrapperCreated (string managedType, string javaType, int jniIdentityHashCode, int managedObjectHashCode, string runtimeMode)
+			{
+				WriteEvent (1, managedType, javaType, jniIdentityHashCode, managedObjectHashCode, runtimeMode);
+			}
+
+			[Event (2, Level = EventLevel.Informational, Keywords = Keywords.WrapperLifecycle)]
+			public void JavaWrapperCreated (string managedType, string javaType, int jniIdentityHashCode, int managedObjectHashCode, string runtimeMode)
+			{
+				WriteEvent (2, managedType, javaType, jniIdentityHashCode, managedObjectHashCode, runtimeMode);
+			}
+
+			[Event (3, Level = EventLevel.Informational, Keywords = Keywords.WrapperLifecycle)]
+			public void DotNetWrapperReleasedJavaReference (string managedType, string javaType, int jniIdentityHashCode, int managedObjectHashCode, string runtimeMode)
+			{
+				WriteEvent (3, managedType, javaType, jniIdentityHashCode, managedObjectHashCode, runtimeMode);
+			}
+
+			[Event (4, Level = EventLevel.Informational, Keywords = Keywords.WrapperLifecycle)]
+			public void JavaWrapperReleasedDotNetReference (string managedType, string javaType, int jniIdentityHashCode, int managedObjectHashCode, string runtimeMode)
+			{
+				WriteEvent (4, managedType, javaType, jniIdentityHashCode, managedObjectHashCode, runtimeMode);
+			}
+
+			[Event (5, Level = EventLevel.Informational, Keywords = Keywords.Reachability)]
+			public void DotNetObjectOnlyReachableFromJava (string managedType, string javaType, int jniIdentityHashCode, int managedObjectHashCode, string runtimeMode, int componentIndex, int contextIndex, long contextPointer)
+			{
+				WriteEvent (5, managedType, javaType, jniIdentityHashCode, managedObjectHashCode, runtimeMode, componentIndex, contextIndex, contextPointer);
+			}
+
+			[Event (6, Level = EventLevel.Informational, Keywords = Keywords.Reachability)]
+			public void JavaObjectOnlyReachableFromDotNet (string managedType, string javaType, int jniIdentityHashCode, int managedObjectHashCode, string runtimeMode, int componentIndex, int contextIndex, long contextPointer)
+			{
+				WriteEvent (6, managedType, javaType, jniIdentityHashCode, managedObjectHashCode, runtimeMode, componentIndex, contextIndex, contextPointer);
+			}
+		}
+	}
+}

external/Java.Interop/src/Java.Interop/Java.Interop/JniRuntime.JniValueManager.cs

@@ -116,6 +116,15 @@ public virtual void DisposePeer (IJavaPeerable value)
 				var h = value.PeerReference;
 				if (!h.IsValid)
 					return;
+				if (InteropEventSource.IsEnabled ()) {
+					var javaType = JniEnvironment.Types.GetJniTypeNameFromInstance (h);
+					InteropEventSource.DotNetWrapperReleasedJavaReference (
+						value.GetType ().FullName,
+						javaType,
+						value.JniIdentityHashCode,
+						RuntimeHelpers.GetHashCode (value),
+						Runtime.GetType ().FullName);
+				}
 
 				DisposePeer (h, value);
 			}

external/Java.Interop/src/Java.Interop/Java.Interop/JniRuntime.ReflectionJniValueManager.cs

@@ -78,6 +78,9 @@ protected override void ConstructPeerCore (IJavaPeerable peer, ref JniObjectRefe
 
 				peer.SetPeerReference (newRef);
 				peer.SetJniIdentityHashCode (JniSystem.IdentityHashCode (newRef));
+				if (!peer.JniManagedPeerState.HasFlag (JniManagedPeerStates.Activatable) && InteropEventSource.IsEnabled ()) {
+					EmitJavaWrapperCreatedEvent (peer, newRef);
+				}
 
 				var o = Runtime.ObjectReferenceManager;
 				if (o.LogGlobalReferenceMessages) {
@@ -94,6 +97,34 @@ protected override void ConstructPeerCore (IJavaPeerable peer, ref JniObjectRefe
 				}
 			}
 
+			void EmitDotNetWrapperCreatedEvent (IJavaPeerable peer)
+			{
+				JniObjectReference reference = peer.PeerReference;
+				var javaType = reference.IsValid ? JniEnvironment.Types.GetJniTypeNameFromInstance (reference) : null;
+				InteropEventSource.DotNetWrapperCreated (
+					peer.GetType ().FullName,
+					javaType,
+					peer.JniIdentityHashCode,
+					RuntimeHelpers.GetHashCode (peer),
+					GetRuntimeMode ());
+			}
+
+			void EmitJavaWrapperCreatedEvent (IJavaPeerable peer, JniObjectReference reference)
+			{
+				var javaType = reference.IsValid ? JniEnvironment.Types.GetJniTypeNameFromInstance (reference) : null;
+				InteropEventSource.JavaWrapperCreated (
+					peer.GetType ().FullName,
+					javaType,
+					peer.JniIdentityHashCode,
+					RuntimeHelpers.GetHashCode (peer),
+					GetRuntimeMode ());
+			}
+
+			string GetRuntimeMode ()
+			{
+				return Runtime.GetType ().FullName ?? "Unknown";
+			}
+
 			// This base method implementation is NOT reachable in trimmable typemap - it is featureswitch guarded
 			public override IJavaPeerable? CreatePeer (
 					ref JniObjectReference reference,
@@ -143,6 +174,9 @@ protected override void ConstructPeerCore (IJavaPeerable peer, ref JniObjectRefe
 							JniEnvironment.Types.GetJniTypeNameFromInstance (reference), targetType));
 				}
 				peer.SetJniManagedPeerState (peer.JniManagedPeerState | JniManagedPeerStates.Replaceable);
+				if (InteropEventSource.IsEnabled ()) {
+					EmitDotNetWrapperCreatedEvent (peer);
+				}
 				return peer;
 			}
 

external/Java.Interop/src/Java.Interop/Java.Interop/ManagedPeer.cs

@@ -8,6 +8,7 @@
 using System.Linq.Expressions;
 using System.Reflection;
 using System.Reflection.Emit;
+using System.Runtime.CompilerServices;
 using System.Runtime.InteropServices;
 using System.Runtime.Serialization;
 using System.Text;
@@ -105,6 +106,15 @@ static void Construct (
 
 				var typeSig = new JniTypeSignature (JniEnvironment.Types.GetJniTypeNameFromInstance (r_self));
 				var type    = GetTypeFromSignature (runtime.TypeManager, typeSig);
+				if (InteropEventSource.IsEnabled ()) {
+					var managedObjectHashCode = self != null ? RuntimeHelpers.GetHashCode (self) : 0;
+					InteropEventSource.JavaWrapperCreated (
+						type.FullName,
+						typeSig.SimpleReference,
+						runtime.ValueManager.GetJniIdentityHashCode (r_self),
+						managedObjectHashCode,
+						runtime.GetType ().FullName);
+				}
 
 				if (type.IsGenericTypeDefinition) {
 					throw new NotSupportedException (

external/Java.Interop/src/Java.Interop/PublicAPI.Unshipped.txt

@@ -117,3 +117,11 @@ override Java.Interop.JniRuntime.ReflectionJniTypeManager.GetTypesForSimpleRefer
 override Java.Interop.JniRuntime.ReflectionJniTypeManager.RegisterNativeMembers(Java.Interop.JniType! nativeClass, System.Type! type, string? methods) -> void
 override Java.Interop.JniRuntime.ReflectionJniTypeManager.RegisterNativeMembers(Java.Interop.JniType! nativeClass, System.Type! type, System.ReadOnlySpan<char> methods) -> void
 virtual Java.Interop.JniRuntime.ReflectionJniValueManager.TryConstructPeer(Java.Interop.IJavaPeerable! self, ref Java.Interop.JniObjectReference reference, Java.Interop.JniObjectReferenceOptions options, System.Type! type) -> bool
+static Java.Interop.InteropEventSource.DotNetObjectOnlyReachableFromJava(string? managedType, string? javaType, int jniIdentityHashCode, int managedObjectHashCode, string? runtimeMode, int componentIndex, int contextIndex, long contextPointer) -> void
+static Java.Interop.InteropEventSource.DotNetWrapperCreated(string? managedType, string? javaType, int jniIdentityHashCode, int managedObjectHashCode, string? runtimeMode) -> void
+static Java.Interop.InteropEventSource.DotNetWrapperReleasedJavaReference(string? managedType, string? javaType, int jniIdentityHashCode, int managedObjectHashCode, string? runtimeMode) -> void
+static Java.Interop.InteropEventSource.IsEnabled() -> bool
+static Java.Interop.InteropEventSource.JavaObjectOnlyReachableFromDotNet(string? managedType, string? javaType, int jniIdentityHashCode, int managedObjectHashCode, string? runtimeMode, int componentIndex, int contextIndex, long contextPointer) -> void
+static Java.Interop.InteropEventSource.JavaWrapperCreated(string? managedType, string? javaType, int jniIdentityHashCode, int managedObjectHashCode, string? runtimeMode) -> void
+static Java.Interop.InteropEventSource.JavaWrapperReleasedDotNetReference(string? managedType, string? javaType, int jniIdentityHashCode, int managedObjectHashCode, string? runtimeMode) -> void
+Java.Interop.InteropEventSource