Add disconnection from service to free up references. (#91)

doc/TROUBLESHOOT.md

@@ -97,4 +97,3 @@ TODO: add example
 
 Such cases are hard to troubleshoot. One way to fix them is to convert all closures,
 which reference the leaked type, to named methods.
-

pkgs/leak_tracker/CHANGELOG.md

@@ -1,3 +1,7 @@
+# 7.0.8
+
+* Disconnect from service after obtaining retaining paths.
+
 # 7.0.7
 
 * Protect from identityHashCode equal to 0.

pkgs/leak_tracker/lib/src/leak_tracking/_object_tracker.dart

@@ -10,6 +10,7 @@ import '_finalizer.dart';
 import '_gc_counter.dart';
 import '_object_record.dart';
 import 'leak_tracker_model.dart';
+import 'retaining_path/_connection.dart';
 import 'retaining_path/_retaining_path.dart';
 
 /// Keeps collection of object records until
@@ -187,14 +188,17 @@ class ObjectTracker implements LeakProvider {
  }
 
  Future<void> _addRetainingPath(List<int> objectsToGetPath) async {
+ final connection = await connect();
  final pathSetters = objectsToGetPath.map((code) async {
  final record = _objects.notGCed[code]!;
- final path = await obtainRetainingPath(record.type, record.code);
+ final path =
+ await obtainRetainingPath(connection, record.type, record.code);
  if (path != null) {
  record.setContext(ContextKeys.retainingPath, path);
  }
  });
  await Future.wait(pathSetters);
+ disconnect();
  }
 
  ObjectRecord _notGCed(int code) {

pkgs/leak_tracker/lib/src/leak_tracking/orchestration.dart

@@ -10,6 +10,7 @@ import '_formatting.dart';
 import '_gc_counter.dart';
 import 'leak_tracker.dart';
 import 'leak_tracker_model.dart';
+import 'retaining_path/_connection.dart';
 import 'retaining_path/_retaining_path.dart';
 
 /// Asynchronous callback.
@@ -95,8 +96,8 @@ Future<Leaks> withLeakTracking(
  await asyncCodeRunner(
  () async {
  if (leakDiagnosticConfig.collectRetainingPathForNonGCed) {
- // This early check is needed to collect retaing pathes before forced GC,
- // because pathes are unavailable for GCed objects.
+ // This early check is needed to collect retaing paths before forced GC,
+ // because paths are unavailable for GCed objects.
  await checkNonGCed();
  }
 
@@ -173,10 +174,13 @@ Future<void> forceGC({
 /// https://github.com/dart-lang/sdk/blob/3e80d29fd6fec56187d651ce22ea81f1e8732214/runtime/vm/object_graph.cc#L1803
 Future<String?> formattedRetainingPath(WeakReference ref) async {
  if (ref.target == null) return null;
+ final connection = await connect();
  final path = await obtainRetainingPath(
+ connection,
  ref.target.runtimeType,
  identityHashCode(ref.target),
  );
+ disconnect();
 
  if (path == null) return null;
  return retainingPathToString(path);

pkgs/leak_tracker/lib/src/leak_tracking/retaining_path/_connection.dart

@@ -41,9 +41,7 @@ Future<Connection> connect() async {
  );
  }
 
- final service = await _connectWithWebSocket(uri, (error) {
- throw error ?? Exception('Error connecting to service protocol');
- });
+ final service = await _connectWithWebSocket(uri, _handleError);
  await service.getVersion(); // Warming up and validating the connection.
  final isolates = await _getTwoIsolates(service);
 
@@ -52,6 +50,8 @@ Future<Connection> connect() async {
  return result;
 }
 
+void _handleError(Object? error) => throw error ?? Exception('Unknown error');
+
 /// Tries to wait for two isolates to be available.
 ///
 /// Depending on environment (command line / IDE, Flutter / Dart), isolates may have different names,

pkgs/leak_tracker/lib/src/leak_tracking/retaining_path/_retaining_path.dart

@@ -13,11 +13,11 @@ import '_connection.dart';
 ///
 /// Does not work for objects that have [identityHashCode] equal to 0.
 /// https://github.com/dart-lang/sdk/blob/3e80d29fd6fec56187d651ce22ea81f1e8732214/runtime/vm/object_graph.cc#L1803
-Future<RetainingPath?> obtainRetainingPath(Type type, int code) async {
- assert(code > 0);
-
- final connection = await connect();
-
+Future<RetainingPath?> obtainRetainingPath(
+ Connection connection,
+ Type type,
+ int code,
+) async {
  final fp = _ObjectFingerprint(type, code);
  final theObject = await _objectInIsolate(connection, fp);
  if (theObject == null) return null;

pkgs/leak_tracker/pubspec.yaml

@@ -1,5 +1,5 @@
 name: leak_tracker
-version: 7.0.7
+version: 7.0.8
 description: A framework for memory leak tracking for Dart and Flutter applications.
 repository: https://github.com/dart-lang/leak_tracker/tree/main/pkgs/leak_tracker
 

pkgs/leak_tracker/test/debug/leak_tracking/retaining_path/_retaining_path_test.dart

@@ -37,33 +37,42 @@ void main() {
 
  test('Path for $MyClass instance is found.', () async {
  final instance = MyClass();
+ final connection = await connect();
 
  final path = await obtainRetainingPath(
+ connection,
  instance.runtimeType,
  identityHashCode(instance),
  );
+ disconnect();
  expect(path!.elements, isNotEmpty);
  });
 
  test('Path for class with generic arg is found.', () async {
  final instance = MyArgClass<String>();
+ final connection = await connect();
+
  final path = await obtainRetainingPath(
+ connection,
  instance.runtimeType,
  identityHashCode(instance),
  );
+ disconnect();
  expect(path!.elements, isNotEmpty);
  });
 
  test('Connection is happening just once', () async {
  final instance1 = MyClass();
  final instance2 = MyClass();
+ final connection = await connect();
 
  final obtainers = [
- obtainRetainingPath(MyClass, identityHashCode(instance1)),
- obtainRetainingPath(MyClass, identityHashCode(instance2)),
+ obtainRetainingPath(connection, MyClass, identityHashCode(instance1)),
+ obtainRetainingPath(connection, MyClass, identityHashCode(instance2)),
  ];
 
  await Future.wait(obtainers);
+ disconnect();
 
  expect(
  _logs.where((item) => item == 'Connecting to vm service protocol...'),