| // Copyright (c) 2022, 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 'dart:io'; |
| import 'dart:_internal'; |
| |
| import 'package:expect/expect.dart'; |
| import 'package:path/path.dart' as path; |
| import 'package:vm_service/vm_service.dart'; |
| |
| import 'use_flag_test_helper.dart'; |
| |
| final bool alwaysTrue = int.parse('1') == 1; |
| |
| @pragma('vm:entry-point') // Prevent name mangling |
| class Foo {} |
| |
| var global = null; |
| |
| main() async { |
| if (const bool.fromEnvironment('dart.vm.product')) { |
| var exception; |
| try { |
| await runTest(); |
| } catch (e) { |
| exception = e; |
| } |
| Expect.contains( |
| 'Heap snapshots are only supported in non-product mode.', '$exception'); |
| return; |
| } |
| |
| await runTest(); |
| } |
| |
| Future runTest() async { |
| await withTempDir('heap_snapshot_test', (String dir) async { |
| final state1 = path.join(dir, 'state1.heapsnapshot'); |
| final state2 = path.join(dir, 'state2.heapsnapshot'); |
| final state3 = path.join(dir, 'state3.heapsnapshot'); |
| |
| var local; |
| |
| VMInternalsForTesting.writeHeapSnapshotToFile(state1); |
| if (alwaysTrue) { |
| global = Foo(); |
| local = Foo(); |
| } |
| VMInternalsForTesting.writeHeapSnapshotToFile(state2); |
| if (alwaysTrue) { |
| global = null; |
| local = null; |
| } |
| VMInternalsForTesting.writeHeapSnapshotToFile(state3); |
| |
| final int count1 = countFooInstances( |
| findReachableObjects(loadHeapSnapshotFromFile(state1))); |
| final int count2 = countFooInstances( |
| findReachableObjects(loadHeapSnapshotFromFile(state2))); |
| final int count3 = countFooInstances( |
| findReachableObjects(loadHeapSnapshotFromFile(state3))); |
| |
| Expect.equals(0, count1); |
| Expect.equals(2, count2); |
| Expect.equals(0, count3); |
| |
| reachabilityFence(local); |
| reachabilityFence(global); |
| }); |
| } |
| |
| HeapSnapshotGraph loadHeapSnapshotFromFile(String filename) { |
| final bytes = File(filename).readAsBytesSync(); |
| return HeapSnapshotGraph.fromChunks([bytes.buffer.asByteData()]); |
| } |
| |
| Set<HeapSnapshotObject> findReachableObjects(HeapSnapshotGraph graph) { |
| const int rootObjectIdx = 1; |
| |
| final reachableObjects = Set<HeapSnapshotObject>(); |
| final worklist = <HeapSnapshotObject>[]; |
| |
| final rootObject = graph.objects[rootObjectIdx]; |
| |
| reachableObjects.add(rootObject); |
| worklist.add(rootObject); |
| |
| while (worklist.isNotEmpty) { |
| final objectToExpand = worklist.removeLast(); |
| |
| for (final successor in objectToExpand.successors) { |
| if (!reachableObjects.contains(successor)) { |
| reachableObjects.add(successor); |
| worklist.add(successor); |
| } |
| } |
| } |
| return reachableObjects; |
| } |
| |
| int countFooInstances(Set<HeapSnapshotObject> reachableObjects) { |
| int count = 0; |
| for (final object in reachableObjects) { |
| if (object.klass.name == 'Foo') count++; |
| } |
| return count; |
| } |