[ Service ] Add support for ID zones to package:dart_runtime_service_vm

Also disables logging by default, which can be enabled by specifying the
`VM_SERVICE_LOGGING` environment variable.

package:vm_service test suite is ~99% passing with this change.
Change-Id: I41578cc8b39afac93589b8792861be34b848f558
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/490921
Reviewed-by: Jessy Yameogo <yjessy@google.com>
Reviewed-by: Nicholas Shahan <nshahan@google.com>

pkg/dart_runtime_service/lib/src/clients.dart

@@ -22,7 +22,8 @@ typedef ServiceAlias = String;
 typedef ServiceNameAliasPair = ({ServiceName service, ServiceAlias alias});
 
 /// Represents a client that is connected to a service.
-base class Client {
+base class Client<BE extends DartRuntimeServiceBackend> {
+  @protected
   Client({
     required this.connection,
     required UnmodifiableClientNamedLookup clients,
@@ -63,7 +64,7 @@ base class Client {
   final StreamChannel<Object?> connection;
   late json_rpc.Peer _clientPeer;
   late final DartRuntimeServiceRpcs _internalRpcs;
-  final DartRuntimeServiceBackend backend;
+  final BE backend;
 
   /// If `true`, this client was created via
   /// [DartRuntimeService.addArtificialClient].
@@ -86,11 +87,7 @@ base class Client {
     logger.info('Initializing...');
     this.namespace = namespace;
     registerRpcHandlers();
-    done = _listen().then((_) {
-      logger.info('Client connection closed.');
-      // Cleanup stream subscription state when the client disconnects.
-      _internalRpcs.eventStreamMethods.onClientDisconnect(this);
-    });
+    done = _listen().then((_) => cleanup());
     logger.info('Initialization complete.');
     return done;
   }
@@ -107,6 +104,14 @@ base class Client {
     await _clientPeer.close();
   }
 
+  @protected
+  @mustCallSuper
+  Future<void> cleanup() async {
+    logger.info('Client connection closed.');
+    // Cleanup stream subscription state when the client disconnects.
+    _internalRpcs.eventStreamMethods.onClientDisconnect(this);
+  }
+
   @mustCallSuper
   void registerRpcHandlers() {
     _internalRpcs
@@ -242,11 +247,12 @@ abstract interface class ClientConnectionController {
 /// service.
 ///
 /// Call [addClient] when a client connects to your service.
-base class ClientManager implements ClientConnectionController {
+base class ClientManager<BE extends DartRuntimeServiceBackend>
+    implements ClientConnectionController {
   ClientManager({required this.backend, required this.eventStreamMethods});
 
   static const _kServicePrologue = 's';
-  final DartRuntimeServiceBackend backend;
+  final BE backend;
   final EventStreamMethods eventStreamMethods;
 
   final _logger = Logger('$ClientManager');
@@ -289,6 +295,25 @@ base class ClientManager implements ClientConnectionController {
     );
   }
 
+  @visibleForOverriding
+  Client clientBuilder({
+    required StreamChannel<Object?> connection,
+    required UnmodifiableClientNamedLookup clients,
+    required EventStreamMethods eventStreamMethods,
+    required BE backend,
+    required bool artificial,
+    String? name,
+  }) {
+    return Client(
+      connection: connection,
+      clients: clients,
+      eventStreamMethods: eventStreamMethods,
+      backend: backend,
+      name: name,
+      artificial: artificial,
+    );
+  }
+
   /// Creates a [Client] from [connection] and adds it to the list of connected
   /// clients.
   ///
@@ -299,7 +324,7 @@ base class ClientManager implements ClientConnectionController {
     String? name,
     bool artificial = false,
   }) {
-    final client = Client(
+    final client = clientBuilder(
       connection: connection,
       clients: clients,
       eventStreamMethods: eventStreamMethods,

pkg/dart_runtime_service/lib/src/dart_runtime_service.dart

@@ -107,10 +107,7 @@ class DartRuntimeService {
   ClientConnectionController get clientConnectionController => clientManager;
 
   @visibleForTesting
-  late final ClientManager clientManager = ClientManager(
-    backend: backend,
-    eventStreamMethods: eventStreamManager,
-  );
+  late final ClientManager clientManager = backend.clientManagerBuilder();
 
   /// The set of currently connected [Client]s.
   UnmodifiableClientNamedLookup get clients => clientManager.clients;

pkg/dart_runtime_service/lib/src/dart_runtime_service_backend.dart

@@ -8,6 +8,7 @@ import 'dart:collection';
 import 'package:meta/meta.dart';
 import 'package:shelf/shelf.dart';
 
+import 'clients.dart';
 import 'dart_runtime_service.dart';
 import 'dart_runtime_service_rpcs.dart';
 import 'event_streams.dart';
@@ -30,6 +31,18 @@ abstract class DartRuntimeServiceBackend<IM extends IsolateManager> {
   /// Adds support for expression evaluation if non-null.
   ExpressionEvaluator? get expressionEvaluator => null;
 
+  /// Used by [DartRuntimeService] to create a [ClientManager].
+  ///
+  /// Backend implementations should override this method and return their own
+  /// [ClientManager] implementation if they require tracking additional state
+  /// for each [Client].
+  ClientManager<DartRuntimeServiceBackend<IM>> clientManagerBuilder() {
+    return ClientManager(
+      backend: this,
+      eventStreamMethods: frontend.eventStreams,
+    );
+  }
+
   /// Invoked by the [DartRuntimeService] when the service is initializing,
   /// before the service's HTTP server is started.
   ///

pkg/dart_runtime_service/test/utils/mocks.dart

@@ -14,6 +14,8 @@ import 'package:test/fake.dart';
 /// a backend implementation.
 base class FakeDartRuntimeServiceBackend extends Fake
     implements DartRuntimeServiceBackend {
+  FakeDartRuntimeServiceBackend({required this.frontend});
+
   @override
   Future<void> initialize() async {}
 
@@ -41,7 +43,7 @@ base class FakeDartRuntimeServiceBackend extends Fake
       UnmodifiableListView(const []);
 
   @override
-  DartRuntimeService get frontend => throw UnimplementedError();
+  final DartRuntimeService frontend;
 
   @override
   IsolateManager get isolateManager => throw UnimplementedError();
@@ -49,6 +51,14 @@ base class FakeDartRuntimeServiceBackend extends Fake
   @override
   ExpressionEvaluator? get expressionEvaluator => null;
 
+  @override
+  ClientManager<DartRuntimeServiceBackend> clientManagerBuilder() {
+    return ClientManager(
+      backend: this,
+      eventStreamMethods: frontend.eventStreams,
+    );
+  }
+
   @override
   void onStreamCancel({required String streamId}) {}
 

pkg/dart_runtime_service/test/utils/utilities.dart

@@ -24,7 +24,8 @@ Future<DartRuntimeService> createDartRuntimeServiceForTest({
 
   service = await DartRuntimeService.initialize(
     config: config,
-    backendBuilder: (_) => FakeDartRuntimeServiceBackend(),
+    backendBuilder: (frontend) =>
+        FakeDartRuntimeServiceBackend(frontend: frontend),
   );
   return service;
 }

pkg/dart_runtime_service_vm/bin/vm_service_entrypoint.dart

@@ -113,7 +113,7 @@ Future<void> main([List<String> args = const []]) async {
   }
   await DartRuntimeService.initialize(
     config: DartRuntimeServiceOptions(
-      enableLogging: true,
+      enableLogging: Platform.environment.containsKey('VM_SERVICE_LOGGING'),
       port: _port,
       disableAuthCodes: _authCodesDisabled,
       disableOriginCheck: _originCheckDisabled,

pkg/dart_runtime_service_vm/lib/dart_runtime_service_vm.dart

@@ -17,6 +17,7 @@ import 'package:stream_channel/stream_channel.dart';
 
 import 'src/dart_runtime_service_vm_rpcs.dart';
 import 'src/native_bindings.dart';
+import 'src/vm_clients.dart';
 import 'src/vm_dev_fs.dart';
 import 'src/vm_expression_evaluator.dart';
 import 'src/vm_isolate_manager.dart';
@@ -79,7 +80,7 @@ class DartRuntimeServiceVMBackend
   @override
   late final VmExpressionEvaluator expressionEvaluator;
 
-  final _vmServiceRpcs = DartRuntimeServiceVmRpcs();
+  late final _vmServiceRpcs = DartRuntimeServiceVmRpcs(backend: this);
 
   /// Adds support for launching and accepting connections from the
   /// Dart Development Service.
@@ -103,6 +104,10 @@ class DartRuntimeServiceVMBackend
   @override
   OptionalHandler get httpHandler => _devFs.handlePutStreamRequest;
 
+  @override
+  VmClientManager clientManagerBuilder() =>
+      VmClientManager(backend: this, eventStreamMethods: frontend.eventStreams);
+
   @override
   Future<void> initialize() async {
     _logger.info('Initializing...');

pkg/dart_runtime_service_vm/lib/src/dart_runtime_service_vm_rpcs.dart

@@ -5,18 +5,34 @@
 import 'dart:collection';
 
 import 'package:dart_runtime_service/dart_runtime_service.dart';
+import 'package:json_rpc_2/json_rpc_2.dart' as json_rpc_2;
 import 'package:logging/logging.dart';
 import 'package:vm_service/vm_service.dart';
 
+import '../dart_runtime_service_vm.dart';
 import 'native_bindings.dart';
+import 'vm_clients.dart';
 
 /// Implementations of RPCs specific to the VM service that are not handled
 /// in runtime/vm/service.cc.
 final class DartRuntimeServiceVmRpcs {
+  DartRuntimeServiceVmRpcs({required this.backend});
+
   final _logger = Logger('$DartRuntimeServiceVmRpcs');
   final _nativeBindings = NativeBindings();
+  final DartRuntimeServiceVMBackend backend;
+
+  static const _kGetSupportedProtocols = 'getSupportedProtocols';
+  static const _kCreateIdZone = 'createIdZone';
+  static const _kDeleteIdZone = 'deleteIdZone';
+
+  static const _kIsolateId = 'isolateId';
+  static const _kIdZoneId = 'idZoneId';
+
   late final rpcs = UnmodifiableListView<ServiceRpcHandler>([
-    ('getSupportedProtocols', getSupportedProtocols),
+    (_kGetSupportedProtocols, getSupportedProtocols),
+    (_kCreateIdZone, createIdZone),
+    (_kDeleteIdZone, deleteIdZone),
   ]);
 
   /// Returns the list of protocols implemented by the service.
@@ -42,4 +58,40 @@ final class DartRuntimeServiceVmRpcs {
       ],
     ).toJson();
   }
+
+  /// Creates a new [IdZone] where temporary IDs for instances in the specified
+  /// isolate may be allocated for [client].
+  Future<RpcResponse> createIdZone(
+    json_rpc_2.Parameters parameters,
+    Client client,
+  ) async {
+    // The implementation of this RPC is in the VM, but we track which zones
+    // have been created by individual clients so we can clean them up when the
+    // clients disconnect.
+    final result = await backend.sendToRuntime(parameters);
+    final idZone = IdZone.parse(result);
+    if (idZone != null) {
+      final isolateId = parameters[_kIsolateId].asString;
+      final vmClient = client as VmClient;
+      vmClient.registerIdZone(isolateId: isolateId, idZone: idZone);
+    }
+    return result;
+  }
+
+  /// Destroys an [IdZone] owned by [client].
+  Future<RpcResponse> deleteIdZone(
+    json_rpc_2.Parameters parameters,
+    Client client,
+  ) async {
+    // The implementation of this RPC is in the VM, but we track which zones
+    // have been created by individual clients so we can clean them up when the
+    // clients disconnect.
+    final result = await backend.sendToRuntime(parameters);
+    final vmClient = client as VmClient;
+    vmClient.unregisterIdZone(
+      isolateId: parameters[_kIsolateId].asString,
+      idZoneId: parameters[_kIdZoneId].asString,
+    );
+    return result;
+  }
 }

pkg/dart_runtime_service_vm/lib/src/vm_clients.dart

@@ -0,0 +1,82 @@
+// Copyright (c) 2026, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+import 'package:dart_runtime_service/dart_runtime_service.dart';
+import 'package:json_rpc_2/json_rpc_2.dart' hide Client;
+import 'package:meta/meta.dart';
+import 'package:stream_channel/stream_channel.dart';
+import 'package:vm_service/vm_service.dart';
+
+import '../dart_runtime_service_vm.dart';
+
+typedef ServiceIDZone = ({IdZone idZone, String isolateId});
+
+/// A [Client] of the VM service.
+final class VmClient extends Client<DartRuntimeServiceVMBackend> {
+  VmClient({
+    required super.connection,
+    required super.clients,
+    required super.eventStreamMethods,
+    required super.backend,
+    required super.artificial,
+    super.name,
+  });
+
+  final _idZones = <ServiceIDZone>{};
+
+  @override
+  @protected
+  Future<void> cleanup() async {
+    await _cleanupIdZones();
+    await super.cleanup();
+  }
+
+  /// Track a newly created [IdZone].
+  void registerIdZone({required String isolateId, required IdZone idZone}) {
+    _idZones.add((idZone: idZone, isolateId: isolateId));
+  }
+
+  /// Stop tracking a recently destroyed [IdZone].
+  void unregisterIdZone({required String isolateId, required String idZoneId}) {
+    _idZones.removeWhere(
+      (e) => e.isolateId == isolateId && e.idZone.id == idZoneId,
+    );
+  }
+
+  Future<void> _cleanupIdZones() async {
+    await Future.wait([
+      for (final (:idZone, :isolateId) in _idZones)
+        backend.sendToRuntime(
+          Parameters('deleteIdZone', {
+            'isolateId': isolateId,
+            'idZoneId': idZone.id!,
+          }),
+        ),
+    ]);
+  }
+}
+
+/// Manages and tracks clients of the VM service.
+final class VmClientManager extends ClientManager<DartRuntimeServiceVMBackend> {
+  VmClientManager({required super.backend, required super.eventStreamMethods});
+
+  @override
+  VmClient clientBuilder({
+    required StreamChannel<Object?> connection,
+    required UnmodifiableClientNamedLookup clients,
+    required EventStreamMethods eventStreamMethods,
+    required DartRuntimeServiceVMBackend backend,
+    required bool artificial,
+    String? name,
+  }) {
+    return VmClient(
+      connection: connection,
+      clients: clients,
+      eventStreamMethods: eventStreamMethods,
+      backend: backend,
+      name: name,
+      artificial: artificial,
+    );
+  }
+}

pkg/dart_runtime_service_vm/lib/src/vm_expression_evaluator.dart

@@ -29,8 +29,8 @@ final class VmExpressionEvaluator extends ExpressionEvaluator {
   static const kScope = 'scope';
   static const kDisableBreakpoints = 'disableBreakpoints';
 
-  // TODO(bkonyi): add ID zone support.
-  // static const kIdZoneId = 'idZoneId';
+  // ID zone support.
+  static const kIdZoneId = 'idZoneId';
 
   // `evaluate` specific parameters.
   static const kTargetId = 'targetId';
@@ -74,6 +74,9 @@ final class VmExpressionEvaluator extends ExpressionEvaluator {
       disableBreakpoints: parameters[kDisableBreakpoints].exists
           ? parameters[kDisableBreakpoints].asBool
           : null,
+      idZoneId: parameters[kIdZoneId].exists
+          ? parameters[kIdZoneId].asString
+          : null,
     );
   }
 
@@ -90,6 +93,9 @@ final class VmExpressionEvaluator extends ExpressionEvaluator {
       disableBreakpoints: parameters[kDisableBreakpoints].exists
           ? parameters[kDisableBreakpoints].asBool
           : null,
+      idZoneId: parameters[kIdZoneId].exists
+          ? parameters[kIdZoneId].asString
+          : null,
     );
   }
 
@@ -105,6 +111,7 @@ final class VmExpressionEvaluator extends ExpressionEvaluator {
     required String? targetId,
     required Map<String, String>? scope,
     required bool? disableBreakpoints,
+    required String? idZoneId,
   }) async {
     final buildScopeResponse = await _buildScope(
       isolateId: isolateId,
@@ -124,6 +131,7 @@ final class VmExpressionEvaluator extends ExpressionEvaluator {
       targetId: targetId,
       scope: scope,
       disableBreakpoints: disableBreakpoints,
+      idZoneId: idZoneId,
       kernelBase64: kernelBase64,
     );
   }
@@ -206,6 +214,7 @@ final class VmExpressionEvaluator extends ExpressionEvaluator {
     required int? frameIndex,
     required String? targetId,
     required bool? disableBreakpoints,
+    required String? idZoneId,
     required String kernelBase64,
   }) {
     final params = <String, Object?>{
@@ -215,6 +224,7 @@ final class VmExpressionEvaluator extends ExpressionEvaluator {
       kFrameIndex: ?frameIndex,
       kTargetId: ?targetId,
       kDisableBreakpoints: ?disableBreakpoints,
+      kIdZoneId: ?idZoneId,
       kKernelBytes: kernelBase64,
     };
     return backend.sendToRuntime(

pkg/dart_runtime_service_vm/pubspec.yaml

@@ -13,5 +13,6 @@ dependencies:
   file: any
   json_rpc_2: any
   logging: any
+  meta: any
   stream_channel: any
   vm_service: any