Commit 6bfd9bb9 authored by Ian Hickson's avatar Ian Hickson Committed by Dan Field

Fix a race condition in vmservice_test.dart (#23835)

Fixes https://github.com/flutter/flutter/issues/19273
parent 17fe191a
......@@ -82,15 +82,13 @@ class FlutterDevice {
vmServices = localVmServices;
}
Future<void> refreshViews() {
Future<void> refreshViews() async {
if (vmServices == null || vmServices.isEmpty)
return Future<void>.value(null);
final List<Future<void>> futures = <Future<void>>[];
for (VMService service in vmServices)
futures.add(service.vm.refreshViews());
final Completer<void> completer = Completer<void>();
Future.wait(futures).whenComplete(() => completer.complete(null)); // ignore: unawaited_futures
return completer.future;
futures.add(service.vm.refreshViews(waitForViews: true));
await Future.wait(futures);
}
List<FlutterView> get views {
......@@ -490,8 +488,10 @@ abstract class ResidentRunner {
}
Future<void> refreshViews() async {
final List<Future<void>> futures = <Future<void>>[];
for (FlutterDevice device in flutterDevices)
await device.refreshViews();
futures.add(device.refreshViews());
await Future.wait(futures);
}
Future<void> _debugDumpApp() async {
......
......@@ -163,7 +163,10 @@ class HotRunner extends ResidentRunner {
}) async {
_didAttach = true;
try {
await connectToServiceProtocol(reloadSources: _reloadSourcesService, compileExpression: _compileExpressionService);
await connectToServiceProtocol(
reloadSources: _reloadSourcesService,
compileExpression: _compileExpressionService,
);
} catch (error) {
printError('Error connecting to the service protocol: $error');
return 2;
......@@ -189,8 +192,10 @@ class HotRunner extends ResidentRunner {
}
final Stopwatch initialUpdateDevFSsTimer = Stopwatch()..start();
final bool devfsResult = await _updateDevFS(fullRestart: true);
_addBenchmarkData('hotReloadInitialDevFSSyncMilliseconds',
initialUpdateDevFSsTimer.elapsed.inMilliseconds);
_addBenchmarkData(
'hotReloadInitialDevFSSyncMilliseconds',
initialUpdateDevFSsTimer.elapsed.inMilliseconds,
);
if (!devfsResult)
return 3;
......@@ -276,7 +281,7 @@ class HotRunner extends ResidentRunner {
return attach(
connectionInfoCompleter: connectionInfoCompleter,
appStartedCompleter: appStartedCompleter
appStartedCompleter: appStartedCompleter,
);
}
......
......@@ -105,7 +105,7 @@ const Duration kShortRequestTimeout = Duration(seconds: 5);
// TODO(flutter/flutter#23031): Test this.
/// A connection to the Dart VM Service.
class VMService {
VMService._(
VMService(
this._peer,
this.httpAddress,
this.wsAddress,
......@@ -236,7 +236,7 @@ class VMService {
final Uri wsUri = httpUri.replace(scheme: 'ws', path: fs.path.join(httpUri.path, 'ws'));
final StreamChannel<String> channel = await _openChannel(wsUri);
final rpc.Peer peer = rpc.Peer.withoutJson(jsonDocument.bind(channel));
final VMService service = VMService._(peer, httpUri, wsUri, requestTimeout, reloadSources, compileExpression);
final VMService service = VMService(peer, httpUri, wsUri, requestTimeout, reloadSources, compileExpression);
// This call is to ensure we are able to establish a connection instead of
// keeping on trucking and failing farther down the process.
await service._sendRequest('getVersion', const <String, dynamic>{});
......@@ -311,7 +311,7 @@ class VMService {
final Map<String, dynamic> eventIsolate = eventData['isolate'];
// Log event information.
printTrace(data.toString());
printTrace('Notification from VM: $data');
ServiceEvent event;
if (eventIsolate != null) {
......@@ -341,15 +341,9 @@ class VMService {
}
/// Reloads the VM.
Future<VM> getVM() async {
return await _vm.reload();
}
Future<void> getVM() async => await vm.reload();
Future<void> refreshViews() async {
if (!vm.isFlutterEngine)
return;
await vm.refreshViews();
}
Future<void> refreshViews({ bool waitForViews = false }) => vm.refreshViews(waitForViews: waitForViews);
}
/// An error that is thrown when constructing/updating a service object.
......@@ -371,9 +365,8 @@ String _stripRef(String type) => _hasRef(type) ? type.substring(1) : type;
/// to return a cached / canonicalized object.
void _upgradeCollection(dynamic collection,
ServiceObjectOwner owner) {
if (collection is ServiceMap) {
if (collection is ServiceMap)
return;
}
if (collection is Map<String, dynamic>) {
_upgradeMap(collection, owner);
} else if (collection is List) {
......@@ -382,7 +375,7 @@ void _upgradeCollection(dynamic collection,
}
void _upgradeMap(Map<String, dynamic> map, ServiceObjectOwner owner) {
map.forEach((String k, dynamic v) {
map.forEach((String k, Object v) {
if ((v is Map<String, dynamic>) && _isServiceMap(v)) {
map[k] = owner.getFromMap(v);
} else if (v is List) {
......@@ -394,8 +387,8 @@ void _upgradeMap(Map<String, dynamic> map, ServiceObjectOwner owner) {
}
void _upgradeList(List<dynamic> list, ServiceObjectOwner owner) {
for (int i = 0; i < list.length; i++) {
final dynamic v = list[i];
for (int i = 0; i < list.length; i += 1) {
final Object v = list[i];
if ((v is Map<String, dynamic>) && _isServiceMap(v)) {
list[i] = owner.getFromMap(v);
} else if (v is List) {
......@@ -477,9 +470,8 @@ abstract class ServiceObject {
/// If this is not already loaded, load it. Otherwise reload.
Future<ServiceObject> load() async {
if (loaded) {
if (loaded)
return this;
}
return reload();
}
......@@ -499,15 +491,12 @@ abstract class ServiceObject {
// We should always reload the VM.
// We can't reload objects without an id.
// We shouldn't reload an immutable and already loaded object.
final bool skipLoad = !isVM && (!hasId || (immutable && loaded));
if (skipLoad) {
if (!isVM && (!hasId || (immutable && loaded)))
return this;
}
if (_inProgressReload == null) {
final Completer<ServiceObject> completer = Completer<ServiceObject>();
_inProgressReload = completer.future;
try {
final Map<String, dynamic> response = await _fetchDirect();
if (_stripRef(response['type']) == 'Sentinel') {
......@@ -661,9 +650,7 @@ class VM extends ServiceObjectOwner {
VM get vm => this;
@override
Future<Map<String, dynamic>> _fetchDirect() async {
return invokeRpcRaw('getVM');
}
Future<Map<String, dynamic>> _fetchDirect() => invokeRpcRaw('getVM');
@override
void _update(Map<String, dynamic> map, bool mapIsRef) {
......@@ -675,11 +662,9 @@ class VM extends ServiceObjectOwner {
_upgradeCollection(map, this);
_loaded = true;
// TODO(johnmccutchan): Extract any properties we care about here.
_pid = map['pid'];
if (map['_heapAllocatedMemoryUsage'] != null) {
if (map['_heapAllocatedMemoryUsage'] != null)
_heapAllocatedMemoryUsage = map['_heapAllocatedMemoryUsage'];
}
_maxRSS = map['_maxRSS'];
_embedder = map['_embedder'];
......@@ -818,6 +803,13 @@ class VM extends ServiceObjectOwner {
return Future<Isolate>.value(_isolateCache[isolateId]);
}
static String _truncate(String message, int width, String ellipsis) {
assert(ellipsis.length < width);
if (message.length <= width)
return message;
return message.substring(0, width - ellipsis.length) + ellipsis;
}
/// Invoke the RPC and return the raw response.
///
/// If `timeoutFatal` is false, then a timeout will result in a null return
......@@ -827,14 +819,14 @@ class VM extends ServiceObjectOwner {
Duration timeout,
bool timeoutFatal = true,
}) async {
printTrace('$method: $params');
printTrace('Sending to VM service: $method($params)');
assert(params != null);
timeout ??= _vmService._requestTimeout;
try {
final Map<String, dynamic> result = await _vmService
._sendRequest(method, params)
.timeout(timeout);
printTrace('Result: ${_truncate(result.toString(), 250, '...')}');
return result;
} on TimeoutException {
printTrace('Request to Dart VM Service timed out: $method($params)');
......@@ -949,12 +941,29 @@ class VM extends ServiceObjectOwner {
return invokeRpcRaw('_getVMTimeline', timeout: kLongRequestTimeout);
}
Future<void> refreshViews() {
Future<void> refreshViews({ bool waitForViews = false }) async {
assert(waitForViews != null);
assert(loaded);
if (!isFlutterEngine)
return Future<void>.value();
_viewCache.clear();
// Send one per-application request that refreshes all views in the app.
return vmService.vm.invokeRpc<ServiceObject>('_flutter.listViews', timeout: kLongRequestTimeout);
return;
int failCount = 0;
while (true) {
_viewCache.clear();
// When the future returned by invokeRpc() below returns,
// the _viewCache will have been updated.
// This message updates all the views of every isolate.
await vmService.vm.invokeRpc<ServiceObject>(
'_flutter.listViews',
timeout: kLongRequestTimeout,
);
if (_viewCache.values.isNotEmpty || !waitForViews)
return;
failCount += 1;
if (failCount == 5) // waited 200ms
printStatus('Flutter is taking longer than expected to report its views. Still trying...');
await Future<void>.delayed(const Duration(milliseconds: 50));
await reload();
}
}
Iterable<FlutterView> get views => _viewCache.values;
......@@ -1080,9 +1089,7 @@ class Isolate extends ServiceObjectOwner {
}
@override
Future<Map<String, dynamic>> _fetchDirect() {
return invokeRpcRaw('getIsolate');
}
Future<Map<String, dynamic>> _fetchDirect() => invokeRpcRaw('getIsolate');
/// Invoke the RPC and return the raw response.
Future<Map<String, dynamic>> invokeRpcRaw(String method, {
......@@ -1427,7 +1434,7 @@ class FlutterView extends ServiceObject {
packagesUri,
assetsDirectoryUri);
await completer.future;
await owner.vm.refreshViews();
await owner.vm.refreshViews(waitForViews: true);
await subscription.cancel();
}
......
......@@ -2,12 +2,158 @@
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
import 'dart:async';
import 'package:flutter_tools/src/base/io.dart';
import 'package:flutter_tools/src/base/logger.dart';
import 'package:flutter_tools/src/vmservice.dart';
import 'package:json_rpc_2/json_rpc_2.dart' as rpc;
import 'package:quiver/testing/async.dart';
import 'src/common.dart';
import 'src/context.dart';
import 'src/mocks.dart';
class MockPeer implements rpc.Peer {
@override
Future<dynamic> get done async {
throw 'unexpected call to done';
}
@override
bool get isClosed {
throw 'unexpected call to isClosed';
}
@override
Future<dynamic> close() async {
throw 'unexpected call to close()';
}
@override
Future<dynamic> listen() async {
// this does get called
}
@override
void registerFallback(dynamic callback(rpc.Parameters parameters)) {
throw 'unexpected call to registerFallback';
}
@override
void registerMethod(String name, Function callback) {
// this does get called
}
@override
void sendNotification(String method, [ dynamic parameters ]) {
throw 'unexpected call to sendNotification';
}
bool isolatesEnabled = false;
Future<void> _getVMLatch;
Completer<void> _currentGetVMLatchCompleter;
void tripGetVMLatch() {
final Completer<void> lastCompleter = _currentGetVMLatchCompleter;
_currentGetVMLatchCompleter = Completer<void>();
_getVMLatch = _currentGetVMLatchCompleter.future;
lastCompleter?.complete();
}
int returnedFromSendRequest = 0;
@override
Future<dynamic> sendRequest(String method, [ dynamic parameters ]) async {
if (method == 'getVM')
await _getVMLatch;
await Future<void>.delayed(Duration.zero);
returnedFromSendRequest += 1;
if (method == 'getVM') {
return <String, dynamic>{
'type': 'VM',
'name': 'vm',
'architectureBits': 64,
'targetCPU': 'x64',
'hostCPU': ' Intel(R) Xeon(R) CPU E5-1650 v2 @ 3.50GHz',
'version': '2.1.0-dev.7.1.flutter-45f9462398 (Fri Oct 19 19:27:56 2018 +0000) on "linux_x64"',
'_profilerMode': 'Dart',
'_nativeZoneMemoryUsage': 0,
'pid': 103707,
'startTime': 1540426121876,
'_embedder': 'Flutter',
'_maxRSS': 312614912,
'_currentRSS': 33091584,
'isolates': isolatesEnabled ? <dynamic>[
<String, dynamic>{
'type': '@Isolate',
'fixedId': true,
'id': 'isolates/242098474',
'name': 'main.dart:main()',
'number': 242098474,
},
] : <dynamic>[],
};
}
if (method == 'getIsolate') {
return <String, dynamic>{
'type': 'Isolate',
'fixedId': true,
'id': 'isolates/242098474',
'name': 'main.dart:main()',
'number': 242098474,
'_originNumber': 242098474,
'startTime': 1540488745340,
'_heaps': <String, dynamic>{
'new': <String, dynamic>{
'used': 0,
'capacity': 0,
'external': 0,
'collections': 0,
'time': 0.0,
'avgCollectionPeriodMillis': 0.0,
},
'old': <String, dynamic>{
'used': 0,
'capacity': 0,
'external': 0,
'collections': 0,
'time': 0.0,
'avgCollectionPeriodMillis': 0.0,
},
},
};
}
if (method == '_flutter.listViews') {
return <String, dynamic>{
'type': 'FlutterViewList',
'views': isolatesEnabled ? <dynamic>[
<String, dynamic>{
'type': 'FlutterView',
'id': '_flutterView/0x4a4c1f8',
'isolate': <String, dynamic>{
'type': '@Isolate',
'fixedId': true,
'id': 'isolates/242098474',
'name': 'main.dart:main()',
'number': 242098474,
},
},
] : <dynamic>[],
};
}
return null;
}
@override
dynamic withBatch(dynamic callback()) {
throw 'unexpected call to withBatch';
}
}
void main() {
final MockStdio mockStdio = MockStdio();
group('VMService', () {
testUsingContext('fails connection eagerly in the connect() method', () async {
expect(
......@@ -15,5 +161,73 @@ void main() {
throwsToolExit(),
);
});
testUsingContext('refreshViews', () {
FakeAsync().run((FakeAsync time) {
bool done = false;
final MockPeer mockPeer = MockPeer();
expect(mockPeer.returnedFromSendRequest, 0);
final VMService vmService = VMService(mockPeer, null, null, const Duration(seconds: 1), null, null);
vmService.getVM().then((void value) { done = true; });
expect(done, isFalse);
expect(mockPeer.returnedFromSendRequest, 0);
time.elapse(Duration.zero);
expect(done, isTrue);
expect(mockPeer.returnedFromSendRequest, 1);
done = false;
mockPeer.tripGetVMLatch(); // this blocks the upcoming getVM call
final Future<void> ready = vmService.refreshViews(waitForViews: true);
ready.then((void value) { done = true; });
expect(mockPeer.returnedFromSendRequest, 1);
time.elapse(Duration.zero); // this unblocks the listViews call which returns nothing
expect(mockPeer.returnedFromSendRequest, 2);
time.elapse(const Duration(milliseconds: 50)); // the last listViews had no views, so it waits 50ms, then calls getVM
expect(done, isFalse);
expect(mockPeer.returnedFromSendRequest, 2);
mockPeer.tripGetVMLatch(); // this unblocks the getVM call
expect(mockPeer.returnedFromSendRequest, 2);
time.elapse(Duration.zero); // here getVM returns with no isolates and listViews returns no views
expect(mockPeer.returnedFromSendRequest, 4);
time.elapse(const Duration(milliseconds: 50)); // so refreshViews waits another 50ms
expect(done, isFalse);
expect(mockPeer.returnedFromSendRequest, 4);
mockPeer.tripGetVMLatch(); // this unblocks the getVM call
expect(mockPeer.returnedFromSendRequest, 4);
time.elapse(Duration.zero); // here getVM returns with no isolates and listViews returns no views
expect(mockPeer.returnedFromSendRequest, 6);
time.elapse(const Duration(milliseconds: 50)); // so refreshViews waits another 50ms
expect(done, isFalse);
expect(mockPeer.returnedFromSendRequest, 6);
mockPeer.tripGetVMLatch(); // this unblocks the getVM call
expect(mockPeer.returnedFromSendRequest, 6);
time.elapse(Duration.zero); // here getVM returns with no isolates and listViews returns no views
expect(mockPeer.returnedFromSendRequest, 8);
time.elapse(const Duration(milliseconds: 50)); // so refreshViews waits another 50ms
expect(done, isFalse);
expect(mockPeer.returnedFromSendRequest, 8);
mockPeer.tripGetVMLatch(); // this unblocks the getVM call
expect(mockPeer.returnedFromSendRequest, 8);
time.elapse(Duration.zero); // here getVM returns with no isolates and listViews returns no views
expect(mockPeer.returnedFromSendRequest, 10);
const String message = 'Flutter is taking longer than expected to report its views. Still trying...\n';
expect(mockStdio.writtenToStdout.join(''), message);
expect(mockStdio.writtenToStderr.join(''), '');
time.elapse(const Duration(milliseconds: 50)); // so refreshViews waits another 50ms
expect(done, isFalse);
expect(mockPeer.returnedFromSendRequest, 10);
mockPeer.isolatesEnabled = true;
mockPeer.tripGetVMLatch(); // this unblocks the getVM call
expect(mockPeer.returnedFromSendRequest, 10);
time.elapse(Duration.zero); // now it returns an isolate and the listViews call returns views
expect(mockPeer.returnedFromSendRequest, 13);
expect(done, isTrue);
expect(mockStdio.writtenToStdout.join(''), message);
expect(mockStdio.writtenToStderr.join(''), '');
});
}, overrides: <Type, Generator>{
Logger: () => StdoutLogger(),
Stdio: () => mockStdio,
});
});
}
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