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Issue 1212513002: sdk files reorganization to make dart2js a proper package (Closed) Base URL: git@github.com:dart-lang/sdk.git@master
Patch Set: renamed Created 5 years, 5 months ago
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1 // Copyright (c) 2012, the Dart project authors. Please see the AUTHORS file
2 // for details. All rights reserved. Use of this source code is governed by a
3 // BSD-style license that can be found in the LICENSE file.
4
5 library _isolate_helper;
6
7 import 'dart:_js_embedded_names' show
8 CLASS_ID_EXTRACTOR,
9 CLASS_FIELDS_EXTRACTOR,
10 CREATE_NEW_ISOLATE,
11 CURRENT_SCRIPT,
12 GLOBAL_FUNCTIONS,
13 INITIALIZE_EMPTY_INSTANCE,
14 INSTANCE_FROM_CLASS_ID;
15
16 import 'dart:async';
17 import 'dart:collection' show Queue;
18 import 'dart:isolate';
19 import 'dart:_native_typed_data' show NativeByteBuffer, NativeTypedData;
20
21 import 'dart:_js_helper' show
22 Closure,
23 InternalMap,
24 Null,
25 Primitives,
26 convertDartClosureToJS,
27 isDartObject,
28 random64,
29 requiresPreamble;
30
31 import 'dart:_foreign_helper' show DART_CLOSURE_TO_JS,
32 JS,
33 JS_CURRENT_ISOLATE_CONTEXT,
34 JS_CURRENT_ISOLATE,
35 JS_EMBEDDED_GLOBAL,
36 JS_SET_CURRENT_ISOLATE,
37 IsolateContext;
38
39 import 'dart:_interceptors' show Interceptor,
40 JSArray,
41 JSExtendableArray,
42 JSFixedArray,
43 JSIndexable,
44 JSMutableArray,
45 JSObject;
46
47
48 part 'isolate_serialization.dart';
49
50 /**
51 * Called by the compiler to support switching
52 * between isolates when we get a callback from the DOM.
53 */
54 _callInIsolate(_IsolateContext isolate, Function function) {
55 var result = isolate.eval(function);
56 // If we are not already running the event-loop start it now.
57 if (!_currentIsolate()._isExecutingEvent) _globalState.topEventLoop.run();
58 return result;
59 }
60
61 /// Marks entering a JavaScript async operation to keep the worker alive.
62 ///
63 /// To be called by library code before starting an async operation controlled
64 /// by the JavaScript event handler.
65 ///
66 /// Also call [leaveJsAsync] in all callback handlers marking the end of that
67 /// async operation (also error handlers) so the worker can be released.
68 ///
69 /// These functions only has to be called for code that can be run from a
70 /// worker-isolate (so not for general dom operations).
71 enterJsAsync() {
72 _globalState.topEventLoop._activeJsAsyncCount++;
73 }
74
75 /// Marks leaving a javascript async operation.
76 ///
77 /// See [enterJsAsync].
78 leaveJsAsync() {
79 _globalState.topEventLoop._activeJsAsyncCount--;
80 assert(_globalState.topEventLoop._activeJsAsyncCount >= 0);
81 }
82
83 /// Returns true if we are currently in a worker context.
84 bool isWorker() => _globalState.isWorker;
85
86 /**
87 * Called by the compiler to fetch the current isolate context.
88 */
89 _IsolateContext _currentIsolate() => _globalState.currentContext;
90
91 /**
92 * Wrapper that takes the dart entry point and runs it within an isolate. The
93 * dart2js compiler will inject a call of the form
94 * [: startRootIsolate(main); :] when it determines that this wrapping
95 * is needed. For single-isolate applications (e.g. hello world), this
96 * call is not emitted.
97 */
98 void startRootIsolate(entry, args) {
99 // The dartMainRunner can inject a new arguments array. We pass the arguments
100 // through a "JS", so that the type-inferrer loses track of it.
101 args = JS("", "#", args);
102 if (args == null) args = [];
103 if (args is! List) {
104 throw new ArgumentError("Arguments to main must be a List: $args");
105 }
106 _globalState = new _Manager(entry);
107
108 // Don't start the main loop again, if we are in a worker.
109 if (_globalState.isWorker) return;
110 final rootContext = new _IsolateContext();
111 _globalState.rootContext = rootContext;
112
113 // BUG(5151491): Setting currentContext should not be necessary, but
114 // because closures passed to the DOM as event handlers do not bind their
115 // isolate automatically we try to give them a reasonable context to live in
116 // by having a "default" isolate (the first one created).
117 _globalState.currentContext = rootContext;
118 if (entry is _MainFunctionArgs) {
119 rootContext.eval(() { entry(args); });
120 } else if (entry is _MainFunctionArgsMessage) {
121 rootContext.eval(() { entry(args, null); });
122 } else {
123 rootContext.eval(entry);
124 }
125 _globalState.topEventLoop.run();
126 }
127
128 /********************************************************
129 Inserted from lib/isolate/dart2js/isolateimpl.dart
130 ********************************************************/
131
132 /**
133 * Concepts used here:
134 *
135 * "manager" - A manager contains one or more isolates, schedules their
136 * execution, and performs other plumbing on their behalf. The isolate
137 * present at the creation of the manager is designated as its "root isolate".
138 * A manager may, for example, be implemented on a web Worker.
139 *
140 * [_Manager] - State present within a manager (exactly once, as a global).
141 *
142 * [_ManagerStub] - A handle held within one manager that allows interaction
143 * with another manager. A target manager may be addressed by zero or more
144 * [_ManagerStub]s.
145 * TODO(ahe): The _ManagerStub concept is broken. It was an attempt
146 * to create a common interface between the native Worker class and
147 * _MainManagerStub.
148 */
149
150 /**
151 * A native object that is shared across isolates. This object is visible to all
152 * isolates running under the same manager (either UI or background web worker).
153 *
154 * This is code that is intended to 'escape' the isolate boundaries in order to
155 * implement the semantics of isolates in JavaScript. Without this we would have
156 * been forced to implement more code (including the top-level event loop) in
157 * JavaScript itself.
158 */
159 // TODO(eub, sigmund): move the "manager" to be entirely in JS.
160 // Running any Dart code outside the context of an isolate gives it
161 // the chance to break the isolate abstraction.
162 _Manager get _globalState => JS("_Manager", "init.globalState");
163
164 set _globalState(_Manager val) {
165 JS("void", "init.globalState = #", val);
166 }
167
168 /** State associated with the current manager. See [globalState]. */
169 // TODO(sigmund): split in multiple classes: global, thread, main-worker states?
170 class _Manager {
171
172 /** Next available isolate id within this [_Manager]. */
173 int nextIsolateId = 0;
174
175 /** id assigned to this [_Manager]. */
176 int currentManagerId = 0;
177
178 /**
179 * Next available manager id. Only used by the main manager to assign a unique
180 * id to each manager created by it.
181 */
182 int nextManagerId = 1;
183
184 /** Context for the currently running [Isolate]. */
185 _IsolateContext currentContext = null;
186
187 /** Context for the root [Isolate] that first run in this [_Manager]. */
188 _IsolateContext rootContext = null;
189
190 /** The top-level event loop. */
191 _EventLoop topEventLoop;
192
193 /** Whether this program is running from the command line. */
194 bool fromCommandLine;
195
196 /** Whether this [_Manager] is running as a web worker. */
197 bool isWorker;
198
199 /** Whether we support spawning web workers. */
200 bool supportsWorkers;
201
202 /**
203 * Whether to use web workers when implementing isolates. Set to false for
204 * debugging/testing.
205 */
206 bool get useWorkers => supportsWorkers;
207
208 /**
209 * Registry of isolates. Isolates must be registered if, and only if, receive
210 * ports are alive. Normally no open receive-ports means that the isolate is
211 * dead, but DOM callbacks could resurrect it.
212 */
213 Map<int, _IsolateContext> isolates;
214
215 /** Reference to the main [_Manager]. Null in the main [_Manager] itself. */
216 _MainManagerStub mainManager;
217
218 /// Registry of active Web Workers. Only used in the main [_Manager].
219 Map<int, dynamic /* Worker */> managers;
220
221 /** The entry point given by [startRootIsolate]. */
222 final Function entry;
223
224 _Manager(this.entry) {
225 _nativeDetectEnvironment();
226 topEventLoop = new _EventLoop();
227 isolates = new Map<int, _IsolateContext>();
228 managers = new Map<int, dynamic>();
229 if (isWorker) { // "if we are not the main manager ourself" is the intent.
230 mainManager = new _MainManagerStub();
231 _nativeInitWorkerMessageHandler();
232 }
233 }
234
235 void _nativeDetectEnvironment() {
236 bool isWindowDefined = globalWindow != null;
237 bool isWorkerDefined = globalWorker != null;
238
239 isWorker = !isWindowDefined && globalPostMessageDefined;
240 supportsWorkers = isWorker
241 || (isWorkerDefined && IsolateNatives.thisScript != null);
242 fromCommandLine = !isWindowDefined && !isWorker;
243 }
244
245 void _nativeInitWorkerMessageHandler() {
246 var function = JS('',
247 "(function (f, a) { return function (e) { f(a, e); }})(#, #)",
248 DART_CLOSURE_TO_JS(IsolateNatives._processWorkerMessage),
249 mainManager);
250 JS("void", r"self.onmessage = #", function);
251 // We ensure dartPrint is defined so that the implementation of the Dart
252 // print method knows what to call.
253 JS('', '''self.dartPrint = self.dartPrint || (function(serialize) {
254 return function (object) {
255 if (self.console && self.console.log) {
256 self.console.log(object)
257 } else {
258 self.postMessage(serialize(object));
259 }
260 }
261 })(#)''', DART_CLOSURE_TO_JS(_serializePrintMessage));
262 }
263
264 static _serializePrintMessage(object) {
265 return _serializeMessage({"command": "print", "msg": object});
266 }
267
268 /**
269 * Close the worker running this code if all isolates are done and
270 * there are no active async JavaScript tasks still running.
271 */
272 void maybeCloseWorker() {
273 if (isWorker
274 && isolates.isEmpty
275 && topEventLoop._activeJsAsyncCount == 0) {
276 mainManager.postMessage(_serializeMessage({'command': 'close'}));
277 }
278 }
279 }
280
281 /** Context information tracked for each isolate. */
282 class _IsolateContext implements IsolateContext {
283 /** Current isolate id. */
284 final int id = _globalState.nextIsolateId++;
285
286 /** Registry of receive ports currently active on this isolate. */
287 final Map<int, RawReceivePortImpl> ports = new Map<int, RawReceivePortImpl>();
288
289 /** Registry of weak receive ports currently active on this isolate. */
290 final Set<int> weakPorts = new Set<int>();
291
292 /** Holds isolate globals (statics and top-level properties). */
293 // native object containing all globals of an isolate.
294 final isolateStatics =
295 JS('', "#()", JS_EMBEDDED_GLOBAL('', CREATE_NEW_ISOLATE));
296
297 final RawReceivePortImpl controlPort = new RawReceivePortImpl._controlPort();
298
299 final Capability pauseCapability = new Capability();
300 final Capability terminateCapability = new Capability(); // License to kill.
301
302 /// Boolean flag set when the initial method of the isolate has been executed.
303 ///
304 /// Used to avoid considering the isolate dead when it has no open
305 /// receive ports and no scheduled timers, because it hasn't had time to
306 /// create them yet.
307 bool initialized = false;
308
309 // TODO(lrn): Store these in single "PauseState" object, so they don't take
310 // up as much room when not pausing.
311 bool isPaused = false;
312 List<_IsolateEvent> delayedEvents = [];
313 Set<Capability> pauseTokens = new Set();
314
315 // Container with the "on exit" handler send-ports and responses.
316 var doneHandlers;
317
318 /**
319 * Queue of functions to call when the current event is complete.
320 *
321 * These events are not just put at the front of the event queue, because
322 * they represent control messages, and should be handled even if the
323 * event queue is paused.
324 */
325 var _scheduledControlEvents;
326 bool _isExecutingEvent = false;
327
328 /** Whether uncaught errors are considered fatal. */
329 bool errorsAreFatal = true;
330
331 // Set of ports that listen to uncaught errors.
332 Set<SendPort> errorPorts = new Set();
333
334 _IsolateContext() {
335 this.registerWeak(controlPort._id, controlPort);
336 }
337
338 void addPause(Capability authentification, Capability resume) {
339 if (pauseCapability != authentification) return;
340 if (pauseTokens.add(resume) && !isPaused) {
341 isPaused = true;
342 }
343 _updateGlobalState();
344 }
345
346 void removePause(Capability resume) {
347 if (!isPaused) return;
348 pauseTokens.remove(resume);
349 if (pauseTokens.isEmpty) {
350 while(delayedEvents.isNotEmpty) {
351 _IsolateEvent event = delayedEvents.removeLast();
352 _globalState.topEventLoop.prequeue(event);
353 }
354 isPaused = false;
355 }
356 _updateGlobalState();
357 }
358
359 void addDoneListener(SendPort responsePort, Object response) {
360 if (doneHandlers == null) {
361 doneHandlers = [];
362 }
363 for (int i = 0; i < doneHandlers.length; i += 2) {
364 if (responsePort == doneHandlers[i]) {
365 doneHandlers[i + 1] = response;
366 return;
367 }
368 }
369 doneHandlers.add(responsePort);
370 doneHandlers.add(response);
371 }
372
373 void removeDoneListener(SendPort responsePort) {
374 if (doneHandlers == null) return;
375 for (int i = 0; i < doneHandlers.length; i += 2) {
376 if (responsePort == doneHandlers[i]) {
377 doneHandlers.removeRange(i, i + 2);
378 return;
379 }
380 }
381 }
382
383 void setErrorsFatal(Capability authentification, bool errorsAreFatal) {
384 if (terminateCapability != authentification) return;
385 this.errorsAreFatal = errorsAreFatal;
386 }
387
388 void handlePing(SendPort responsePort, int pingType, Object response) {
389 if (pingType == Isolate.IMMEDIATE ||
390 (pingType == Isolate.BEFORE_NEXT_EVENT &&
391 !_isExecutingEvent)) {
392 responsePort.send(response);
393 return;
394 }
395 void respond() { responsePort.send(response); }
396 assert(pingType == Isolate.BEFORE_NEXT_EVENT);
397 if (_scheduledControlEvents == null) {
398 _scheduledControlEvents = new Queue();
399 }
400 _scheduledControlEvents.addLast(respond);
401 }
402
403 void handleKill(Capability authentification, int priority) {
404 if (this.terminateCapability != authentification) return;
405 if (priority == Isolate.IMMEDIATE ||
406 (priority == Isolate.BEFORE_NEXT_EVENT &&
407 !_isExecutingEvent)) {
408 kill();
409 return;
410 }
411 assert(priority == Isolate.BEFORE_NEXT_EVENT);
412 if (_scheduledControlEvents == null) {
413 _scheduledControlEvents = new Queue();
414 }
415 _scheduledControlEvents.addLast(kill);
416 }
417
418 void addErrorListener(SendPort port) {
419 errorPorts.add(port);
420 }
421
422 void removeErrorListener(SendPort port) {
423 errorPorts.remove(port);
424 }
425
426 /** Function called with an uncaught error. */
427 void handleUncaughtError(error, StackTrace stackTrace) {
428 // Just print the error if there is no error listener registered.
429 if (errorPorts.isEmpty) {
430 // An uncaught error in the root isolate will terminate the program?
431 if (errorsAreFatal && identical(this, _globalState.rootContext)) {
432 // The error will be rethrown to reach the global scope, so
433 // don't print it.
434 return;
435 }
436 if (JS('bool', 'self.console && self.console.error')) {
437 JS('void', 'self.console.error(#, #)', error, stackTrace);
438 } else {
439 print(error);
440 if (stackTrace != null) print(stackTrace);
441 }
442 return;
443 }
444 List message = new List(2)
445 ..[0] = error.toString()
446 ..[1] = (stackTrace == null) ? null : stackTrace.toString();
447 for (SendPort port in errorPorts) port.send(message);
448 }
449
450 /**
451 * Run [code] in the context of the isolate represented by [this].
452 */
453 dynamic eval(Function code) {
454 var old = _globalState.currentContext;
455 _globalState.currentContext = this;
456 this._setGlobals();
457 var result = null;
458 var oldIsExecutingEvent = _isExecutingEvent;
459 _isExecutingEvent = true;
460 try {
461 result = code();
462 } catch (e, s) {
463 handleUncaughtError(e, s);
464 if (errorsAreFatal) {
465 kill();
466 // An uncaught error in the root context terminates all isolates.
467 if (identical(this, _globalState.rootContext)) {
468 rethrow;
469 }
470 }
471 } finally {
472 _isExecutingEvent = oldIsExecutingEvent;
473 _globalState.currentContext = old;
474 if (old != null) old._setGlobals();
475 if (_scheduledControlEvents != null) {
476 while (_scheduledControlEvents.isNotEmpty) {
477 (_scheduledControlEvents.removeFirst())();
478 }
479 }
480 }
481 return result;
482 }
483
484 void _setGlobals() {
485 JS_SET_CURRENT_ISOLATE(isolateStatics);
486 }
487
488 /**
489 * Handle messages comming in on the control port.
490 *
491 * These events do not go through the event queue.
492 * The `_globalState.currentContext` context is not set to this context
493 * during the handling.
494 */
495 void handleControlMessage(message) {
496 switch (message[0]) {
497 case "pause":
498 addPause(message[1], message[2]);
499 break;
500 case "resume":
501 removePause(message[1]);
502 break;
503 case 'add-ondone':
504 addDoneListener(message[1], message[2]);
505 break;
506 case 'remove-ondone':
507 removeDoneListener(message[1]);
508 break;
509 case 'set-errors-fatal':
510 setErrorsFatal(message[1], message[2]);
511 break;
512 case "ping":
513 handlePing(message[1], message[2], message[3]);
514 break;
515 case "kill":
516 handleKill(message[1], message[2]);
517 break;
518 case "getErrors":
519 addErrorListener(message[1]);
520 break;
521 case "stopErrors":
522 removeErrorListener(message[1]);
523 break;
524 default:
525 }
526 }
527
528 /** Looks up a port registered for this isolate. */
529 RawReceivePortImpl lookup(int portId) => ports[portId];
530
531 void _addRegistration(int portId, RawReceivePortImpl port) {
532 if (ports.containsKey(portId)) {
533 throw new Exception("Registry: ports must be registered only once.");
534 }
535 ports[portId] = port;
536 }
537
538 /** Registers a port on this isolate. */
539 void register(int portId, RawReceivePortImpl port) {
540 _addRegistration(portId, port);
541 _updateGlobalState();
542 }
543
544 /**
545 * Registers a weak port on this isolate.
546 *
547 * The port does not keep the isolate active.
548 */
549 void registerWeak(int portId, RawReceivePortImpl port) {
550 weakPorts.add(portId);
551 _addRegistration(portId, port);
552 }
553
554 void _updateGlobalState() {
555 if (ports.length - weakPorts.length > 0 || isPaused || !initialized) {
556 _globalState.isolates[id] = this; // indicate this isolate is active
557 } else {
558 kill();
559 }
560 }
561
562 void kill() {
563 if (_scheduledControlEvents != null) {
564 // Kill all pending events.
565 _scheduledControlEvents.clear();
566 }
567 // Stop listening on all ports.
568 // This should happen before sending events to done handlers, in case
569 // we are listening on ourselves.
570 // Closes all ports, including control port.
571 for (var port in ports.values) {
572 port._close();
573 }
574 ports.clear();
575 weakPorts.clear();
576 _globalState.isolates.remove(id); // indicate this isolate is not active
577 errorPorts.clear();
578 if (doneHandlers != null) {
579 for (int i = 0; i < doneHandlers.length; i += 2) {
580 SendPort responsePort = doneHandlers[i];
581 Object response = doneHandlers[i + 1];
582 responsePort.send(response);
583 }
584 doneHandlers = null;
585 }
586 }
587
588 /** Unregister a port on this isolate. */
589 void unregister(int portId) {
590 ports.remove(portId);
591 weakPorts.remove(portId);
592 _updateGlobalState();
593 }
594 }
595
596 /** Represent the event loop on a javascript thread (DOM or worker). */
597 class _EventLoop {
598 final Queue<_IsolateEvent> events = new Queue<_IsolateEvent>();
599
600 /// The number of waiting callbacks not controlled by the dart event loop.
601 ///
602 /// This could be timers or http requests. The worker will only be killed if
603 /// this count reaches 0.
604 /// Access this by using [enterJsAsync] before starting a JavaScript async
605 /// operation and [leaveJsAsync] when the callback has fired.
606 int _activeJsAsyncCount = 0;
607
608 _EventLoop();
609
610 void enqueue(isolate, fn, msg) {
611 events.addLast(new _IsolateEvent(isolate, fn, msg));
612 }
613
614 void prequeue(_IsolateEvent event) {
615 events.addFirst(event);
616 }
617
618 _IsolateEvent dequeue() {
619 if (events.isEmpty) return null;
620 return events.removeFirst();
621 }
622
623 void checkOpenReceivePortsFromCommandLine() {
624 if (_globalState.rootContext != null
625 && _globalState.isolates.containsKey(_globalState.rootContext.id)
626 && _globalState.fromCommandLine
627 && _globalState.rootContext.ports.isEmpty) {
628 // We want to reach here only on the main [_Manager] and only
629 // on the command-line. In the browser the isolate might
630 // still be alive due to DOM callbacks, but the presumption is
631 // that on the command-line, no future events can be injected
632 // into the event queue once it's empty. Node has setTimeout
633 // so this presumption is incorrect there. We think(?) that
634 // in d8 this assumption is valid.
635 throw new Exception("Program exited with open ReceivePorts.");
636 }
637 }
638
639 /** Process a single event, if any. */
640 bool runIteration() {
641 final event = dequeue();
642 if (event == null) {
643 checkOpenReceivePortsFromCommandLine();
644 _globalState.maybeCloseWorker();
645 return false;
646 }
647 event.process();
648 return true;
649 }
650
651 /**
652 * Runs multiple iterations of the run-loop. If possible, each iteration is
653 * run asynchronously.
654 */
655 void _runHelper() {
656 if (globalWindow != null) {
657 // Run each iteration from the browser's top event loop.
658 void next() {
659 if (!runIteration()) return;
660 Timer.run(next);
661 }
662 next();
663 } else {
664 // Run synchronously until no more iterations are available.
665 while (runIteration()) {}
666 }
667 }
668
669 /**
670 * Call [_runHelper] but ensure that worker exceptions are propagated.
671 */
672 void run() {
673 if (!_globalState.isWorker) {
674 _runHelper();
675 } else {
676 try {
677 _runHelper();
678 } catch (e, trace) {
679 _globalState.mainManager.postMessage(_serializeMessage(
680 {'command': 'error', 'msg': '$e\n$trace' }));
681 }
682 }
683 }
684 }
685
686 /** An event in the top-level event queue. */
687 class _IsolateEvent {
688 _IsolateContext isolate;
689 Function fn;
690 String message;
691
692 _IsolateEvent(this.isolate, this.fn, this.message);
693
694 void process() {
695 if (isolate.isPaused) {
696 isolate.delayedEvents.add(this);
697 return;
698 }
699 isolate.eval(fn);
700 }
701 }
702
703 /** A stub for interacting with the main manager. */
704 class _MainManagerStub {
705 void postMessage(msg) {
706 // "self" is a way to refer to the global context object that
707 // works in HTML pages and in Web Workers. It does not work in d8
708 // and Firefox jsshell, because that would have been too easy.
709 //
710 // See: http://www.w3.org/TR/workers/#the-global-scope
711 // and: http://www.w3.org/TR/Window/#dfn-self-attribute
712 requiresPreamble();
713 JS("void", r"self.postMessage(#)", msg);
714 }
715 }
716
717 const String _SPAWNED_SIGNAL = "spawned";
718 const String _SPAWN_FAILED_SIGNAL = "spawn failed";
719
720 get globalWindow {
721 requiresPreamble();
722 return JS('', "self.window");
723 }
724
725 get globalWorker {
726 requiresPreamble();
727 return JS('', "self.Worker");
728 }
729 bool get globalPostMessageDefined {
730 requiresPreamble();
731 return JS('bool', "!!self.postMessage");
732 }
733
734 typedef _MainFunction();
735 typedef _MainFunctionArgs(args);
736 typedef _MainFunctionArgsMessage(args, message);
737
738 /// Note: IsolateNatives depends on _globalState which is only set up correctly
739 /// when 'dart:isolate' has been imported.
740 class IsolateNatives {
741
742 // We set [enableSpawnWorker] to true (not null) when calling isolate
743 // primitives that require support for spawning workers. The field starts out
744 // by being null, and dart2js' type inference will track if it can have a
745 // non-null value. So by testing if this value is not null, we generate code
746 // that dart2js knows is dead when worker support isn't needed.
747 // TODO(herhut): Initialize this to false when able to track compile-time
748 // constants.
749 static var enableSpawnWorker;
750
751 static String thisScript = computeThisScript();
752
753 /// Associates an ID with a native worker object.
754 static final Expando<int> workerIds = new Expando<int>();
755
756 /**
757 * The src url for the script tag that loaded this function.
758 *
759 * Used to create JavaScript workers and load deferred libraries.
760 */
761 static String computeThisScript() {
762 var currentScript = JS_EMBEDDED_GLOBAL('', CURRENT_SCRIPT);
763 if (currentScript != null) {
764 return JS('String', 'String(#.src)', currentScript);
765 }
766 // A worker has no script tag - so get an url from a stack-trace.
767 if (_globalState.isWorker) return computeThisScriptFromTrace();
768 return null;
769 }
770
771 static String computeThisScriptFromTrace() {
772 var stack = JS('String|Null', 'new Error().stack');
773 if (stack == null) {
774 // According to Internet Explorer documentation, the stack
775 // property is not set until the exception is thrown. The stack
776 // property was not provided until IE10.
777 stack = JS('String|Null',
778 '(function() {'
779 'try { throw new Error() } catch(e) { return e.stack }'
780 '})()');
781 if (stack == null) throw new UnsupportedError('No stack trace');
782 }
783 var pattern, matches;
784
785 // This pattern matches V8, Chrome, and Internet Explorer stack
786 // traces that look like this:
787 // Error
788 // at methodName (URI:LINE:COLUMN)
789 pattern = JS('',
790 r'new RegExp("^ *at [^(]*\\((.*):[0-9]*:[0-9]*\\)$", "m")');
791
792
793 matches = JS('JSExtendableArray|Null', '#.match(#)', stack, pattern);
794 if (matches != null) return JS('String', '#[1]', matches);
795
796 // This pattern matches Firefox stack traces that look like this:
797 // methodName@URI:LINE
798 pattern = JS('', r'new RegExp("^[^@]*@(.*):[0-9]*$", "m")');
799
800 matches = JS('JSExtendableArray|Null', '#.match(#)', stack, pattern);
801 if (matches != null) return JS('String', '#[1]', matches);
802
803 throw new UnsupportedError('Cannot extract URI from "$stack"');
804 }
805
806 /**
807 * Assume that [e] is a browser message event and extract its message data.
808 * We don't import the dom explicitly so, when workers are disabled, this
809 * library can also run on top of nodejs.
810 */
811 static _getEventData(e) => JS("", "#.data", e);
812
813 /**
814 * Process messages on a worker, either to control the worker instance or to
815 * pass messages along to the isolate running in the worker.
816 */
817 static void _processWorkerMessage(/* Worker */ sender, e) {
818 var msg = _deserializeMessage(_getEventData(e));
819 switch (msg['command']) {
820 case 'start':
821 _globalState.currentManagerId = msg['id'];
822 String functionName = msg['functionName'];
823 Function entryPoint = (functionName == null)
824 ? _globalState.entry
825 : _getJSFunctionFromName(functionName);
826 var args = msg['args'];
827 var message = _deserializeMessage(msg['msg']);
828 var isSpawnUri = msg['isSpawnUri'];
829 var startPaused = msg['startPaused'];
830 var replyTo = _deserializeMessage(msg['replyTo']);
831 var context = new _IsolateContext();
832 _globalState.topEventLoop.enqueue(context, () {
833 _startIsolate(entryPoint, args, message,
834 isSpawnUri, startPaused, replyTo);
835 }, 'worker-start');
836 // Make sure we always have a current context in this worker.
837 // TODO(7907): This is currently needed because we're using
838 // Timers to implement Futures, and this isolate library
839 // implementation uses Futures. We should either stop using
840 // Futures in this library, or re-adapt if Futures get a
841 // different implementation.
842 _globalState.currentContext = context;
843 _globalState.topEventLoop.run();
844 break;
845 case 'spawn-worker':
846 if (enableSpawnWorker != null) handleSpawnWorkerRequest(msg);
847 break;
848 case 'message':
849 SendPort port = msg['port'];
850 // If the port has been closed, we ignore the message.
851 if (port != null) {
852 msg['port'].send(msg['msg']);
853 }
854 _globalState.topEventLoop.run();
855 break;
856 case 'close':
857 _globalState.managers.remove(workerIds[sender]);
858 JS('void', '#.terminate()', sender);
859 _globalState.topEventLoop.run();
860 break;
861 case 'log':
862 _log(msg['msg']);
863 break;
864 case 'print':
865 if (_globalState.isWorker) {
866 _globalState.mainManager.postMessage(
867 _serializeMessage({'command': 'print', 'msg': msg}));
868 } else {
869 print(msg['msg']);
870 }
871 break;
872 case 'error':
873 throw msg['msg'];
874 }
875 }
876
877 static handleSpawnWorkerRequest(msg) {
878 var replyPort = msg['replyPort'];
879 spawn(msg['functionName'], msg['uri'],
880 msg['args'], msg['msg'],
881 false, msg['isSpawnUri'], msg['startPaused']).then((msg) {
882 replyPort.send(msg);
883 }, onError: (String errorMessage) {
884 replyPort.send([_SPAWN_FAILED_SIGNAL, errorMessage]);
885 });
886 }
887
888 /** Log a message, forwarding to the main [_Manager] if appropriate. */
889 static _log(msg) {
890 if (_globalState.isWorker) {
891 _globalState.mainManager.postMessage(
892 _serializeMessage({'command': 'log', 'msg': msg }));
893 } else {
894 try {
895 _consoleLog(msg);
896 } catch (e, trace) {
897 throw new Exception(trace);
898 }
899 }
900 }
901
902 static void _consoleLog(msg) {
903 requiresPreamble();
904 JS("void", r"self.console.log(#)", msg);
905 }
906
907 static _getJSFunctionFromName(String functionName) {
908 var globalFunctionsContainer = JS_EMBEDDED_GLOBAL("", GLOBAL_FUNCTIONS);
909 return JS("", "#[#]()", globalFunctionsContainer, functionName);
910 }
911
912 /**
913 * Get a string name for the function, if possible. The result for
914 * anonymous functions is browser-dependent -- it may be "" or "anonymous"
915 * but you should probably not count on this.
916 */
917 static String _getJSFunctionName(Function f) {
918 return (f is Closure) ? JS("String|Null", r'#.$name', f) : null;
919 }
920
921 /** Create a new JavaScript object instance given its constructor. */
922 static dynamic _allocate(var ctor) {
923 return JS("", "new #()", ctor);
924 }
925
926 static Future<List> spawnFunction(void topLevelFunction(message),
927 var message,
928 bool startPaused) {
929 IsolateNatives.enableSpawnWorker = true;
930 final name = _getJSFunctionName(topLevelFunction);
931 if (name == null) {
932 throw new UnsupportedError(
933 "only top-level functions can be spawned.");
934 }
935 bool isLight = false;
936 bool isSpawnUri = false;
937 return spawn(name, null, null, message, isLight, isSpawnUri, startPaused);
938 }
939
940 static Future<List> spawnUri(Uri uri, List<String> args, var message,
941 bool startPaused) {
942 IsolateNatives.enableSpawnWorker = true;
943 bool isLight = false;
944 bool isSpawnUri = true;
945 return spawn(null, uri.toString(), args, message,
946 isLight, isSpawnUri, startPaused);
947 }
948
949 // TODO(sigmund): clean up above, after we make the new API the default:
950
951 /// If [uri] is `null` it is replaced with the current script.
952 static Future<List> spawn(String functionName, String uri,
953 List<String> args, message,
954 bool isLight, bool isSpawnUri, bool startPaused) {
955 // Assume that the compiled version of the Dart file lives just next to the
956 // dart file.
957 // TODO(floitsch): support precompiled version of dart2js output.
958 if (uri != null && uri.endsWith(".dart")) uri += ".js";
959
960 ReceivePort port = new ReceivePort();
961 Completer<List> completer = new Completer();
962 port.first.then((msg) {
963 if (msg[0] == _SPAWNED_SIGNAL) {
964 completer.complete(msg);
965 } else {
966 assert(msg[0] == _SPAWN_FAILED_SIGNAL);
967 completer.completeError(msg[1]);
968 }
969 });
970
971 SendPort signalReply = port.sendPort;
972
973 if (_globalState.useWorkers && !isLight) {
974 _startWorker(
975 functionName, uri, args, message, isSpawnUri, startPaused,
976 signalReply, (String message) => completer.completeError(message));
977 } else {
978 _startNonWorker(
979 functionName, uri, args, message, isSpawnUri, startPaused,
980 signalReply);
981 }
982 return completer.future;
983 }
984
985 static void _startWorker(
986 String functionName, String uri,
987 List<String> args, message,
988 bool isSpawnUri,
989 bool startPaused,
990 SendPort replyPort,
991 void onError(String message)) {
992 // Make sure that the args list is a fresh generic list. A newly spawned
993 // isolate should be able to assume that the arguments list is an
994 // extendable list.
995 if (args != null) args = new List<String>.from(args);
996 if (_globalState.isWorker) {
997 _globalState.mainManager.postMessage(_serializeMessage({
998 'command': 'spawn-worker',
999 'functionName': functionName,
1000 'args': args,
1001 'msg': message,
1002 'uri': uri,
1003 'isSpawnUri': isSpawnUri,
1004 'startPaused': startPaused,
1005 'replyPort': replyPort}));
1006 } else {
1007 _spawnWorker(functionName, uri, args, message,
1008 isSpawnUri, startPaused, replyPort, onError);
1009 }
1010 }
1011
1012 static void _startNonWorker(
1013 String functionName, String uri,
1014 List<String> args, var message,
1015 bool isSpawnUri,
1016 bool startPaused,
1017 SendPort replyPort) {
1018 // TODO(eub): support IE9 using an iframe -- Dart issue 1702.
1019 if (uri != null) {
1020 throw new UnsupportedError(
1021 "Currently spawnUri is not supported without web workers.");
1022 }
1023 // Clone the message to enforce the restrictions we have on isolate
1024 // messages.
1025 message = _clone(message);
1026 // Make sure that the args list is a fresh generic list. A newly spawned
1027 // isolate should be able to assume that the arguments list is an
1028 // extendable list.
1029 if (args != null) args = new List<String>.from(args);
1030 _globalState.topEventLoop.enqueue(new _IsolateContext(), () {
1031 final func = _getJSFunctionFromName(functionName);
1032 _startIsolate(func, args, message, isSpawnUri, startPaused, replyPort);
1033 }, 'nonworker start');
1034 }
1035
1036 static Isolate get currentIsolate {
1037 _IsolateContext context = JS_CURRENT_ISOLATE_CONTEXT();
1038 return new Isolate(context.controlPort.sendPort,
1039 pauseCapability: context.pauseCapability,
1040 terminateCapability: context.terminateCapability);
1041 }
1042
1043 static void _startIsolate(Function topLevel,
1044 List<String> args, message,
1045 bool isSpawnUri,
1046 bool startPaused,
1047 SendPort replyTo) {
1048 _IsolateContext context = JS_CURRENT_ISOLATE_CONTEXT();
1049 Primitives.initializeStatics(context.id);
1050 // The isolate's port does not keep the isolate open.
1051 replyTo.send([_SPAWNED_SIGNAL,
1052 context.controlPort.sendPort,
1053 context.pauseCapability,
1054 context.terminateCapability]);
1055
1056 void runStartFunction() {
1057 context.initialized = true;
1058 if (!isSpawnUri) {
1059 topLevel(message);
1060 } else if (topLevel is _MainFunctionArgsMessage) {
1061 topLevel(args, message);
1062 } else if (topLevel is _MainFunctionArgs) {
1063 topLevel(args);
1064 } else {
1065 topLevel();
1066 }
1067 }
1068
1069 if (startPaused) {
1070 context.addPause(context.pauseCapability, context.pauseCapability);
1071 _globalState.topEventLoop.enqueue(context, runStartFunction,
1072 'start isolate');
1073 } else {
1074 runStartFunction();
1075 }
1076 }
1077
1078 /**
1079 * Spawns an isolate in a worker. [factoryName] is the Javascript constructor
1080 * name for the isolate entry point class.
1081 */
1082 static void _spawnWorker(functionName, String uri,
1083 List<String> args, message,
1084 bool isSpawnUri,
1085 bool startPaused,
1086 SendPort replyPort,
1087 void onError(String message)) {
1088 if (uri == null) uri = thisScript;
1089 final worker = JS('var', 'new Worker(#)', uri);
1090 // Trampolines are used when wanting to call a Dart closure from
1091 // JavaScript. The helper function DART_CLOSURE_TO_JS only accepts
1092 // top-level or static methods, and the trampoline allows us to capture
1093 // arguments and values which can be passed to a static method.
1094 final onerrorTrampoline = JS(
1095 '',
1096 '''
1097 (function (f, u, c) {
1098 return function(e) {
1099 return f(e, u, c)
1100 }
1101 })(#, #, #)''',
1102 DART_CLOSURE_TO_JS(workerOnError), uri, onError);
1103 JS('void', '#.onerror = #', worker, onerrorTrampoline);
1104
1105 var processWorkerMessageTrampoline = JS(
1106 '',
1107 """
1108 (function (f, a) {
1109 return function (e) {
1110 // We can stop listening for errors when the first message is received as
1111 // we only listen for messages to determine if the uri was bad.
1112 e.onerror = null;
1113 return f(a, e);
1114 }
1115 })(#, #)""",
1116 DART_CLOSURE_TO_JS(_processWorkerMessage),
1117 worker);
1118 JS('void', '#.onmessage = #', worker, processWorkerMessageTrampoline);
1119 var workerId = _globalState.nextManagerId++;
1120 // We also store the id on the worker itself so that we can unregister it.
1121 workerIds[worker] = workerId;
1122 _globalState.managers[workerId] = worker;
1123 JS('void', '#.postMessage(#)', worker, _serializeMessage({
1124 'command': 'start',
1125 'id': workerId,
1126 // Note: we serialize replyPort twice because the child worker needs to
1127 // first deserialize the worker id, before it can correctly deserialize
1128 // the port (port deserialization is sensitive to what is the current
1129 // workerId).
1130 'replyTo': _serializeMessage(replyPort),
1131 'args': args,
1132 'msg': _serializeMessage(message),
1133 'isSpawnUri': isSpawnUri,
1134 'startPaused': startPaused,
1135 'functionName': functionName }));
1136 }
1137
1138 static bool workerOnError(
1139 /* Event */ event,
1140 String uri,
1141 void onError(String message)) {
1142 // Attempt to shut up the browser, as the error has been handled. Chrome
1143 // ignores this :-(
1144 JS('void', '#.preventDefault()', event);
1145 String message = JS('String|Null', '#.message', event);
1146 if (message == null) {
1147 // Some browsers, including Chrome, fail to provide a proper error
1148 // event.
1149 message = 'Error spawning worker for $uri';
1150 } else {
1151 message = 'Error spawning worker for $uri ($message)';
1152 }
1153 onError(message);
1154 return true;
1155 }
1156 }
1157
1158 /********************************************************
1159 Inserted from lib/isolate/dart2js/ports.dart
1160 ********************************************************/
1161
1162 /** Common functionality to all send ports. */
1163 abstract class _BaseSendPort implements SendPort {
1164 /** Id for the destination isolate. */
1165 final int _isolateId;
1166
1167 const _BaseSendPort(this._isolateId);
1168
1169 void _checkReplyTo(SendPort replyTo) {
1170 if (replyTo != null
1171 && replyTo is! _NativeJsSendPort
1172 && replyTo is! _WorkerSendPort) {
1173 throw new Exception("SendPort.send: Illegal replyTo port type");
1174 }
1175 }
1176
1177 void send(var message);
1178 bool operator ==(var other);
1179 int get hashCode;
1180 }
1181
1182 /** A send port that delivers messages in-memory via native JavaScript calls. */
1183 class _NativeJsSendPort extends _BaseSendPort implements SendPort {
1184 final RawReceivePortImpl _receivePort;
1185
1186 const _NativeJsSendPort(this._receivePort, int isolateId) : super(isolateId);
1187
1188 void send(var message) {
1189 // Check that the isolate still runs and the port is still open
1190 final isolate = _globalState.isolates[_isolateId];
1191 if (isolate == null) return;
1192 if (_receivePort._isClosed) return;
1193 // Clone the message to enforce the restrictions we have on isolate
1194 // messages.
1195 var msg = _clone(message);
1196 if (isolate.controlPort == _receivePort) {
1197 isolate.handleControlMessage(msg);
1198 return;
1199 }
1200 _globalState.topEventLoop.enqueue(isolate, () {
1201 if (!_receivePort._isClosed) {
1202 _receivePort._add(msg);
1203 }
1204 }, 'receive $message');
1205 }
1206
1207 bool operator ==(var other) => (other is _NativeJsSendPort) &&
1208 (_receivePort == other._receivePort);
1209
1210 int get hashCode => _receivePort._id;
1211 }
1212
1213 /** A send port that delivers messages via worker.postMessage. */
1214 // TODO(eub): abstract this for iframes.
1215 class _WorkerSendPort extends _BaseSendPort implements SendPort {
1216 final int _workerId;
1217 final int _receivePortId;
1218
1219 const _WorkerSendPort(this._workerId, int isolateId, this._receivePortId)
1220 : super(isolateId);
1221
1222 void send(var message) {
1223 final workerMessage = _serializeMessage({
1224 'command': 'message',
1225 'port': this,
1226 'msg': message});
1227
1228 if (_globalState.isWorker) {
1229 // Communication from one worker to another go through the
1230 // main worker.
1231 _globalState.mainManager.postMessage(workerMessage);
1232 } else {
1233 // Deliver the message only if the worker is still alive.
1234 /* Worker */ var manager = _globalState.managers[_workerId];
1235 if (manager != null) {
1236 JS('void', '#.postMessage(#)', manager, workerMessage);
1237 }
1238 }
1239 }
1240
1241 bool operator ==(var other) {
1242 return (other is _WorkerSendPort) &&
1243 (_workerId == other._workerId) &&
1244 (_isolateId == other._isolateId) &&
1245 (_receivePortId == other._receivePortId);
1246 }
1247
1248 int get hashCode {
1249 // TODO(sigmund): use a standard hash when we get one available in corelib.
1250 return (_workerId << 16) ^ (_isolateId << 8) ^ _receivePortId;
1251 }
1252 }
1253
1254 class RawReceivePortImpl implements RawReceivePort {
1255 static int _nextFreeId = 1;
1256
1257 final int _id;
1258 Function _handler;
1259 bool _isClosed = false;
1260
1261 RawReceivePortImpl(this._handler) : _id = _nextFreeId++ {
1262 _globalState.currentContext.register(_id, this);
1263 }
1264
1265 RawReceivePortImpl.weak(this._handler) : _id = _nextFreeId++ {
1266 _globalState.currentContext.registerWeak(_id, this);
1267 }
1268
1269 // Creates the control port of an isolate.
1270 // This is created before the isolate context object itself,
1271 // so it cannot access the static _nextFreeId field.
1272 RawReceivePortImpl._controlPort() : _handler = null, _id = 0;
1273
1274 void set handler(Function newHandler) {
1275 _handler = newHandler;
1276 }
1277
1278 // Close the port without unregistering it.
1279 // Used by an isolate context to close all ports when shutting down.
1280 void _close() {
1281 _isClosed = true;
1282 _handler = null;
1283 }
1284
1285 void close() {
1286 if (_isClosed) return;
1287 _isClosed = true;
1288 _handler = null;
1289 _globalState.currentContext.unregister(_id);
1290 }
1291
1292 void _add(dataEvent) {
1293 if (_isClosed) return;
1294 _handler(dataEvent);
1295 }
1296
1297 SendPort get sendPort {
1298 return new _NativeJsSendPort(this, _globalState.currentContext.id);
1299 }
1300 }
1301
1302 class ReceivePortImpl extends Stream implements ReceivePort {
1303 final RawReceivePort _rawPort;
1304 StreamController _controller;
1305
1306 ReceivePortImpl() : this.fromRawReceivePort(new RawReceivePortImpl(null));
1307
1308 ReceivePortImpl.weak()
1309 : this.fromRawReceivePort(new RawReceivePortImpl.weak(null));
1310
1311 ReceivePortImpl.fromRawReceivePort(this._rawPort) {
1312 _controller = new StreamController(onCancel: close, sync: true);
1313 _rawPort.handler = _controller.add;
1314 }
1315
1316 StreamSubscription listen(void onData(var event),
1317 {Function onError,
1318 void onDone(),
1319 bool cancelOnError}) {
1320 return _controller.stream.listen(onData, onError: onError, onDone: onDone,
1321 cancelOnError: cancelOnError);
1322 }
1323
1324 void close() {
1325 _rawPort.close();
1326 _controller.close();
1327 }
1328
1329 SendPort get sendPort => _rawPort.sendPort;
1330 }
1331
1332 class TimerImpl implements Timer {
1333 final bool _once;
1334 bool _inEventLoop = false;
1335 int _handle;
1336
1337 TimerImpl(int milliseconds, void callback())
1338 : _once = true {
1339 if (milliseconds == 0 && (!hasTimer() || _globalState.isWorker)) {
1340
1341 void internalCallback() {
1342 _handle = null;
1343 callback();
1344 }
1345
1346 // Setting _handle to something different from null indicates that the
1347 // callback has not been run. Hence, the choice of 1 is arbitrary.
1348 _handle = 1;
1349
1350 // This makes a dependency between the async library and the
1351 // event loop of the isolate library. The compiler makes sure
1352 // that the event loop is compiled if [Timer] is used.
1353 // TODO(7907): In case of web workers, we need to use the event
1354 // loop instead of setTimeout, to make sure the futures get executed in
1355 // order.
1356 _globalState.topEventLoop.enqueue(
1357 _globalState.currentContext, internalCallback, 'timer');
1358 _inEventLoop = true;
1359 } else if (hasTimer()) {
1360
1361 void internalCallback() {
1362 _handle = null;
1363 leaveJsAsync();
1364 callback();
1365 }
1366
1367 enterJsAsync();
1368
1369 _handle = JS('int', 'self.setTimeout(#, #)',
1370 convertDartClosureToJS(internalCallback, 0),
1371 milliseconds);
1372 } else {
1373 assert(milliseconds > 0);
1374 throw new UnsupportedError("Timer greater than 0.");
1375 }
1376 }
1377
1378 TimerImpl.periodic(int milliseconds, void callback(Timer timer))
1379 : _once = false {
1380 if (hasTimer()) {
1381 enterJsAsync();
1382 _handle = JS('int', 'self.setInterval(#, #)',
1383 convertDartClosureToJS(() { callback(this); }, 0),
1384 milliseconds);
1385 } else {
1386 throw new UnsupportedError("Periodic timer.");
1387 }
1388 }
1389
1390 void cancel() {
1391 if (hasTimer()) {
1392 if (_inEventLoop) {
1393 throw new UnsupportedError("Timer in event loop cannot be canceled.");
1394 }
1395 if (_handle == null) return;
1396 leaveJsAsync();
1397 if (_once) {
1398 JS('void', 'self.clearTimeout(#)', _handle);
1399 } else {
1400 JS('void', 'self.clearInterval(#)', _handle);
1401 }
1402 _handle = null;
1403 } else {
1404 throw new UnsupportedError("Canceling a timer.");
1405 }
1406 }
1407
1408 bool get isActive => _handle != null;
1409 }
1410
1411 bool hasTimer() {
1412 requiresPreamble();
1413 return JS('', 'self.setTimeout') != null;
1414 }
1415
1416
1417 /**
1418 * Implementation class for [Capability].
1419 *
1420 * It has the same name to make it harder for users to distinguish.
1421 */
1422 class CapabilityImpl implements Capability {
1423 /** Internal random secret identifying the capability. */
1424 final int _id;
1425
1426 CapabilityImpl() : this._internal(random64());
1427
1428 CapabilityImpl._internal(this._id);
1429
1430 int get hashCode {
1431 // Thomas Wang 32 bit Mix.
1432 // http://www.concentric.net/~Ttwang/tech/inthash.htm
1433 // (via https://gist.github.com/badboy/6267743)
1434 int hash = _id;
1435 hash = (hash >> 0) ^ (hash ~/ 0x100000000); // To 32 bit from ~64.
1436 hash = (~hash + (hash << 15)) & 0xFFFFFFFF;
1437 hash ^= hash >> 12;
1438 hash = (hash * 5) & 0xFFFFFFFF;
1439 hash ^= hash >> 4;
1440 hash = (hash * 2057) & 0xFFFFFFFF;
1441 hash ^= hash >> 16;
1442 return hash;
1443 }
1444
1445 bool operator==(Object other) {
1446 if (identical(other, this)) return true;
1447 if (other is CapabilityImpl) {
1448 return identical(_id, other._id);
1449 }
1450 return false;
1451 }
1452 }
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