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| 1 // Copyright (c) 2013, 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 schedule; | |
| 6 | |
| 7 import 'dart:async'; | |
| 8 import 'dart:collection'; | |
| 9 | |
| 10 import 'package:stack_trace/stack_trace.dart'; | |
| 11 | |
| 12 import 'mock_clock.dart' as mock_clock; | |
| 13 import 'schedule_error.dart'; | |
| 14 import 'substitute_future.dart'; | |
| 15 import 'task.dart'; | |
| 16 import 'utils.dart'; | |
| 17 | |
| 18 /// The schedule of tasks to run for a single test. This has three separate task | |
| 19 /// queues: [tasks], [onComplete], and [onException]. It also provides | |
| 20 /// visibility into the current state of the schedule. | |
| 21 class Schedule { | |
| 22 /// The main task queue for the schedule. These tasks are run before the other | |
| 23 /// queues and generally constitute the main test body. | |
| 24 TaskQueue get tasks => _tasks; | |
| 25 TaskQueue _tasks; | |
| 26 | |
| 27 /// The queue of tasks to run if an error is caught while running [tasks]. The | |
| 28 /// error will be available in [errors]. These tasks won't be run if no error | |
| 29 /// occurs. Note that expectation failures count as errors. | |
| 30 /// | |
| 31 /// This queue runs before [onComplete], and errors in [onComplete] will not | |
| 32 /// cause this queue to be run. | |
| 33 /// | |
| 34 /// If an error occurs in a task in this queue, all further tasks will be | |
| 35 /// skipped. | |
| 36 TaskQueue get onException => _onException; | |
| 37 TaskQueue _onException; | |
| 38 | |
| 39 /// The queue of tasks to run after [tasks] and possibly [onException] have | |
| 40 /// run. This queue will run whether or not an error occurred. If one did, it | |
| 41 /// will be available in [errors]. Note that expectation failures count as | |
| 42 /// errors. | |
| 43 /// | |
| 44 /// This queue runs after [onException]. If an error occurs while running | |
| 45 /// [onException], that error will be available in [errors] after the original | |
| 46 /// error. | |
| 47 /// | |
| 48 /// If an error occurs in a task in this queue, all further tasks will be | |
| 49 /// skipped. | |
| 50 TaskQueue get onComplete => _onComplete; | |
| 51 TaskQueue _onComplete; | |
| 52 | |
| 53 /// Returns the [Task] that's currently executing, or `null` if there is no | |
| 54 /// such task. This will be `null` both before the schedule starts running and | |
| 55 /// after it's finished. | |
| 56 Task get currentTask => _currentTask; | |
| 57 Task _currentTask; | |
| 58 | |
| 59 /// The current state of the schedule. | |
| 60 ScheduleState get state => _state; | |
| 61 ScheduleState _state = ScheduleState.SET_UP; | |
| 62 | |
| 63 /// Errors thrown by the task queues. | |
| 64 /// | |
| 65 /// When running tasks in [tasks], this will always be empty. If an error | |
| 66 /// occurs in [tasks], it will be added to this list and then [onException] | |
| 67 /// will be run. If an error occurs there as well, it will be added to this | |
| 68 /// list and [onComplete] will be run. Errors thrown during [onComplete] will | |
| 69 /// also be added to this list, although no scheduled tasks will be run | |
| 70 /// afterwards. | |
| 71 /// | |
| 72 /// Any out-of-band callbacks that throw errors will also have those errors | |
| 73 /// added to this list. | |
| 74 List<ScheduleError> get errors => | |
| 75 new UnmodifiableListView<ScheduleError>(_errors); | |
| 76 final _errors = <ScheduleError>[]; | |
| 77 | |
| 78 /// Additional debugging info registered via [addDebugInfo]. | |
| 79 List<String> get debugInfo => new UnmodifiableListView<String>(_debugInfo); | |
| 80 final _debugInfo = <String>[]; | |
| 81 | |
| 82 /// The task queue that's currently being run. One of [tasks], [onException], | |
| 83 /// or [onComplete]. This starts as [tasks], and can only be `null` after the | |
| 84 /// schedule is done. | |
| 85 TaskQueue get currentQueue => | |
| 86 _state == ScheduleState.DONE ? null : _currentQueue; | |
| 87 TaskQueue _currentQueue; | |
| 88 | |
| 89 /// The time to wait before terminating a task queue for inactivity. Defaults | |
| 90 /// to 5 seconds. This can be set to `null` to disable timeouts entirely. Note | |
| 91 /// that the timeout is the maximum time a task is allowed between | |
| 92 /// interactions with the schedule, *not* the maximum time an entire test is | |
| 93 /// allowed. See also [heartbeat]. | |
| 94 /// | |
| 95 /// If a task queue times out, an error will be raised that can be handled as | |
| 96 /// usual in the [onException] and [onComplete] queues. If [onException] times | |
| 97 /// out, that can only be handled in [onComplete]; if [onComplete] times out, | |
| 98 /// that cannot be handled. | |
| 99 /// | |
| 100 /// If a task times out and then later completes with an error, that error | |
| 101 /// cannot be handled. The user will still be notified of it. | |
| 102 Duration get timeout => _timeout; | |
| 103 Duration _timeout = new Duration(seconds: 5); | |
| 104 set timeout(Duration duration) { | |
| 105 _timeout = duration; | |
| 106 heartbeat(); | |
| 107 } | |
| 108 | |
| 109 /// The timer for keeping track of task timeouts. This may be null. | |
| 110 Timer _timeoutTimer; | |
| 111 | |
| 112 /// Creates a new schedule with empty task queues. | |
| 113 Schedule() { | |
| 114 _tasks = new TaskQueue._("tasks", this); | |
| 115 _onComplete = new TaskQueue._("onComplete", this); | |
| 116 _onException = new TaskQueue._("onException", this); | |
| 117 _currentQueue = _tasks; | |
| 118 | |
| 119 heartbeat(); | |
| 120 } | |
| 121 | |
| 122 /// Sets up this schedule by running [setUp], then runs all the task queues in | |
| 123 /// order. Any errors in [setUp] will cause [onException] to run. | |
| 124 Future run(void setUp()) { | |
| 125 return new Future.value().then((_) { | |
| 126 try { | |
| 127 setUp(); | |
| 128 } catch (e, stackTrace) { | |
| 129 // Even though the scheduling failed, we need to run the onException and | |
| 130 // onComplete queues, so we set the schedule state to RUNNING. | |
| 131 _state = ScheduleState.RUNNING; | |
| 132 throw new ScheduleError.from(this, e, stackTrace: stackTrace); | |
| 133 } | |
| 134 | |
| 135 _state = ScheduleState.RUNNING; | |
| 136 return tasks._run(); | |
| 137 }).catchError((error, stackTrace) { | |
| 138 _addError(error, stackTrace); | |
| 139 return onException._run().catchError((innerError, innerTrace) { | |
| 140 // If an error occurs in a task in the onException queue, make sure it's | |
| 141 // registered in the error list and re-throw it. We could also re-throw | |
| 142 // `error`; ultimately, all the errors will be shown to the user if any | |
| 143 // ScheduleError is thrown. | |
| 144 _addError(innerError, innerTrace); | |
| 145 throw innerError; | |
| 146 }).then((_) { | |
| 147 // If there are no errors in the onException queue, re-throw the | |
| 148 // original error that caused it to run. | |
| 149 throw error; | |
| 150 }); | |
| 151 }).whenComplete(() { | |
| 152 return onComplete._run().catchError((error, stackTrace) { | |
| 153 // If an error occurs in a task in the onComplete queue, make sure it's | |
| 154 // registered in the error list and re-throw it. | |
| 155 _addError(error, stackTrace); | |
| 156 throw error; | |
| 157 }); | |
| 158 }).whenComplete(() { | |
| 159 if (_timeoutTimer != null) _timeoutTimer.cancel(); | |
| 160 _state = ScheduleState.DONE; | |
| 161 }); | |
| 162 } | |
| 163 | |
| 164 /// Stop the current [TaskQueue] after the current task and any out-of-band | |
| 165 /// tasks stop executing. If this is called before [this] has started running, | |
| 166 /// no tasks in the [tasks] queue will be run. | |
| 167 /// | |
| 168 /// This won't cause an error, but any errors that are otherwise signaled will | |
| 169 /// still cause the test to fail. | |
| 170 void abort() { | |
| 171 if (_state == ScheduleState.DONE) { | |
| 172 throw new StateError("Called abort() after the schedule has finished " | |
| 173 "running."); | |
| 174 } | |
| 175 | |
| 176 currentQueue._abort(); | |
| 177 } | |
| 178 | |
| 179 /// Signals that an out-of-band error has occurred. Using [wrapAsync] along | |
| 180 /// with `throw` is usually preferable to calling this directly. | |
| 181 /// | |
| 182 /// The metadata in [ScheduleError]s will be preserved. | |
| 183 void signalError(error, [stackTrace]) { | |
| 184 heartbeat(); | |
| 185 | |
| 186 var scheduleError = new ScheduleError.from(this, error, | |
| 187 stackTrace: stackTrace); | |
| 188 if (_state == ScheduleState.DONE) { | |
| 189 throw new StateError( | |
| 190 "An out-of-band error was signaled outside of wrapAsync after the " | |
| 191 "schedule finished running.\n" | |
| 192 "${errorString()}"); | |
| 193 } else if (state == ScheduleState.SET_UP) { | |
| 194 // If we're setting up, throwing the error will pipe it into the main | |
| 195 // error-handling code. | |
| 196 throw scheduleError; | |
| 197 } else { | |
| 198 _currentQueue._signalError(scheduleError); | |
| 199 } | |
| 200 } | |
| 201 | |
| 202 /// Adds [info] to the debugging output that will be printed if the test | |
| 203 /// fails. Unlike [signalError], this won't cause the test to fail, nor will | |
| 204 /// it short-circuit the current [TaskQueue]; it's just useful for providing | |
| 205 /// additional information that may not fit cleanly into an existing error. | |
| 206 void addDebugInfo(String info) => _debugInfo.add(info); | |
| 207 | |
| 208 /// Notifies the schedule of an error that occurred in a task or out-of-band | |
| 209 /// callback after the appropriate queue has timed out. If this schedule is | |
| 210 /// still running, the error will be added to the errors list to be shown | |
| 211 /// along with the timeout error; otherwise, a top-level error will be thrown. | |
| 212 void _signalPostTimeoutError(error, [stackTrace]) { | |
| 213 var scheduleError = new ScheduleError.from(this, error, | |
| 214 stackTrace: stackTrace); | |
| 215 _addError(scheduleError); | |
| 216 if (_state == ScheduleState.DONE) { | |
| 217 throw new StateError( | |
| 218 "An out-of-band error was caught after the test timed out.\n" | |
| 219 "${errorString()}"); | |
| 220 } | |
| 221 } | |
| 222 | |
| 223 /// Returns a function wrapping [fn] that pipes any errors into the schedule | |
| 224 /// chain. This will also block the current task queue from completing until | |
| 225 /// the returned function has been called. It's used to ensure that | |
| 226 /// out-of-band callbacks are properly handled by the scheduled test. | |
| 227 /// | |
| 228 /// [description] provides an optional description of the callback, which is | |
| 229 /// used when generating error messages. | |
| 230 /// | |
| 231 /// The top-level `wrapAsync` function should usually be used in preference to | |
| 232 /// this in test code. | |
| 233 Function wrapAsync(fn(arg), [String description]) { | |
| 234 if (_state == ScheduleState.DONE) { | |
| 235 throw new StateError("wrapAsync called after the schedule has finished " | |
| 236 "running."); | |
| 237 } | |
| 238 heartbeat(); | |
| 239 | |
| 240 return currentQueue._wrapAsync(fn, description); | |
| 241 } | |
| 242 | |
| 243 /// Like [wrapAsync], this ensures that the current task queue waits for | |
| 244 /// out-of-band asynchronous code, and that errors raised in that code are | |
| 245 /// handled correctly. However, [wrapFuture] wraps a [Future] chain rather | |
| 246 /// than a single callback. | |
| 247 /// | |
| 248 /// The returned [Future] completes to the same value or error as [future]. | |
| 249 /// | |
| 250 /// [description] provides an optional description of the future, which is | |
| 251 /// used when generating error messages. | |
| 252 /// | |
| 253 /// The top-level `wrapFuture` function should usually be used in preference | |
| 254 /// to this in test code. | |
| 255 Future wrapFuture(Future future, [String description]) { | |
| 256 var done = wrapAsync((fn) => fn(), description); | |
| 257 | |
| 258 future = future.then((result) => done(() => result)) | |
| 259 .catchError((error, stackTrace) { | |
| 260 done(() { | |
| 261 throw new ScheduleError.from(this, error, stackTrace: stackTrace); | |
| 262 }); | |
| 263 // wrapAsync will catch the first throw, so we throw [e] again so it | |
| 264 // propagates through the Future chain. | |
| 265 throw error; | |
| 266 }); | |
| 267 | |
| 268 // Don't top-level the error, since it's already been signaled to the | |
| 269 // schedule. | |
| 270 future.catchError((_) => null); | |
| 271 | |
| 272 return future; | |
| 273 } | |
| 274 | |
| 275 /// Returns a string representation of all errors registered on this schedule. | |
| 276 String errorString() { | |
| 277 if (errors.isEmpty) return "The schedule had no errors."; | |
| 278 if (errors.length == 1 && debugInfo.isEmpty) return errors.first.toString(); | |
| 279 | |
| 280 var border = "\n===========================================================" | |
| 281 "=====================\n"; | |
| 282 var errorStrings = errors.map((e) => e.toString()).join(border); | |
| 283 var message = "The schedule had ${errors.length} errors:\n$errorStrings"; | |
| 284 | |
| 285 if (!debugInfo.isEmpty) { | |
| 286 message = "$message$border\nDebug info:\n${debugInfo.join(border)}"; | |
| 287 } | |
| 288 | |
| 289 return message; | |
| 290 } | |
| 291 | |
| 292 /// Notifies the schedule that progress is being made on an asynchronous task. | |
| 293 /// This resets the timeout timer, and can be used in long-running tasks to | |
| 294 /// keep them from timing out. | |
| 295 void heartbeat() { | |
| 296 if (_timeoutTimer != null) _timeoutTimer.cancel(); | |
| 297 if (_timeout == null) { | |
| 298 _timeoutTimer = null; | |
| 299 } else { | |
| 300 _timeoutTimer = mock_clock.newTimer(_timeout, () { | |
| 301 _timeoutTimer = null; | |
| 302 currentQueue._signalTimeout(new ScheduleError.from(this, "The schedule " | |
| 303 "timed out after $_timeout of inactivity.")); | |
| 304 }); | |
| 305 } | |
| 306 } | |
| 307 | |
| 308 /// Register an error in the schedule's error list. This ensures that there | |
| 309 /// are no duplicate errors, and that all errors are wrapped in | |
| 310 /// [ScheduleError]. | |
| 311 void _addError(error, [StackTrace stackTrace]) { | |
| 312 error = new ScheduleError.from(this, error, stackTrace: stackTrace); | |
| 313 if (errors.contains(error)) return; | |
| 314 _errors.add(error); | |
| 315 } | |
| 316 } | |
| 317 | |
| 318 /// An enum of states for a [Schedule]. | |
| 319 class ScheduleState { | |
| 320 /// The schedule can have tasks added to its queue, but is not yet running | |
| 321 /// them. | |
| 322 static const SET_UP = const ScheduleState._("SET_UP"); | |
| 323 | |
| 324 /// The schedule is actively running tasks. This includes running tasks in | |
| 325 /// [Schedule.onException] and [Schedule.onComplete]. | |
| 326 static const RUNNING = const ScheduleState._("RUNNING"); | |
| 327 | |
| 328 /// The schedule has finished running all its tasks, either successfully or | |
| 329 /// with an error. | |
| 330 static const DONE = const ScheduleState._("DONE"); | |
| 331 | |
| 332 /// The name of the state. | |
| 333 final String name; | |
| 334 | |
| 335 const ScheduleState._(this.name); | |
| 336 | |
| 337 String toString() => name; | |
| 338 } | |
| 339 | |
| 340 /// A queue of asynchronous tasks to execute in order. | |
| 341 class TaskQueue { | |
| 342 /// The tasks in the queue. | |
| 343 List<Task> get contents => new UnmodifiableListView<Task>(_contents); | |
| 344 final _contents = new Queue<Task>(); | |
| 345 | |
| 346 /// The name of the queue, for debugging purposes. | |
| 347 final String name; | |
| 348 | |
| 349 /// The [Schedule] that created this queue. | |
| 350 final Schedule _schedule; | |
| 351 | |
| 352 /// An out-of-band error signaled by [_schedule]. If this is non-null, it | |
| 353 /// indicates that the queue should stop as soon as possible and re-throw this | |
| 354 /// error. | |
| 355 ScheduleError _error; | |
| 356 | |
| 357 /// The [SubstituteFuture] for the currently-running task in the queue, or | |
| 358 /// null if no task is currently running. | |
| 359 SubstituteFuture _taskFuture; | |
| 360 | |
| 361 /// The toal number of out-of-band callbacks that have been registered on | |
| 362 /// [this]. | |
| 363 int _totalCallbacks = 0; | |
| 364 | |
| 365 /// Whether to stop running after the current task. | |
| 366 bool _aborted = false; | |
| 367 | |
| 368 /// The descriptions of all callbacks that are blocking the completion of | |
| 369 /// [this]. | |
| 370 List<PendingCallback> get pendingCallbacks => | |
| 371 new UnmodifiableListView<PendingCallback>(_pendingCallbacks); | |
| 372 final _pendingCallbacks = new Queue<PendingCallback>(); | |
| 373 | |
| 374 /// A completer that will be completed once [_pendingCallbacks] becomes empty | |
| 375 /// after the queue finishes running its tasks. | |
| 376 Future get _noPendingCallbacks => _noPendingCallbacksCompleter.future; | |
| 377 final Completer _noPendingCallbacksCompleter = new Completer(); | |
| 378 | |
| 379 /// A [Future] that completes when the tasks in [this] are all complete. If an | |
| 380 /// error occurs while running this queue, the returned [Future] will complete | |
| 381 /// with that error. | |
| 382 /// | |
| 383 /// The returned [Future] can complete before outstanding out-of-band | |
| 384 /// callbacks have finished running. | |
| 385 Future get onTasksComplete => _onTasksCompleteCompleter.future; | |
| 386 final _onTasksCompleteCompleter = new Completer(); | |
| 387 | |
| 388 TaskQueue._(this.name, this._schedule) { | |
| 389 // Avoid top-leveling errors that are passed to onTasksComplete if there are | |
| 390 // no listeners. | |
| 391 onTasksComplete.catchError((_) {}); | |
| 392 } | |
| 393 | |
| 394 /// Whether this queue is currently running. | |
| 395 bool get isRunning => _schedule.state == ScheduleState.RUNNING && | |
| 396 _schedule.currentQueue == this; | |
| 397 | |
| 398 /// Whether this queue is running its tasks (as opposed to waiting for | |
| 399 /// out-of-band callbacks or not running at all). | |
| 400 bool get isRunningTasks => isRunning && _schedule.currentTask != null; | |
| 401 | |
| 402 /// Schedules a task, [fn], to run asynchronously as part of this queue. Tasks | |
| 403 /// will be run in the order they're scheduled. In [fn] returns a [Future], | |
| 404 /// tasks after it won't be run until that [Future] completes. | |
| 405 /// | |
| 406 /// The return value will be completed once the scheduled task has finished | |
| 407 /// running. Its return value is the same as the return value of [fn], or the | |
| 408 /// value it completes to if it's a [Future]. | |
| 409 /// | |
| 410 /// If [description] is passed, it's used to describe the task for debugging | |
| 411 /// purposes when an error occurs. | |
| 412 /// | |
| 413 /// If this is called when this queue is currently running, it will run [fn] | |
| 414 /// on the next event loop iteration rather than adding it to a queue--this is | |
| 415 /// known as a "nested task". The current task will not complete until [fn] | |
| 416 /// (and any [Future] it returns) has finished running. Any errors in [fn] | |
| 417 /// will automatically be handled. Nested tasks run in parallel, unlike | |
| 418 /// top-level tasks which run in sequence. | |
| 419 Future schedule(fn(), [String description]) { | |
| 420 if (isRunning) { | |
| 421 var task = _schedule.currentTask; | |
| 422 var wrappedFn = () => _schedule.wrapFuture( | |
| 423 new Future.value().then((_) => fn())); | |
| 424 if (task == null) return wrappedFn(); | |
| 425 return task.runChild(wrappedFn, description); | |
| 426 } | |
| 427 | |
| 428 var task = new Task(() { | |
| 429 return syncFuture(fn).catchError((e, stackTrace) { | |
| 430 throw new ScheduleError.from(_schedule, e, stackTrace: stackTrace); | |
| 431 }); | |
| 432 }, description, this); | |
| 433 _contents.add(task); | |
| 434 return task.result; | |
| 435 } | |
| 436 | |
| 437 /// Runs all the tasks in this queue in order. | |
| 438 Future _run() { | |
| 439 _schedule._currentQueue = this; | |
| 440 _schedule.heartbeat(); | |
| 441 return Future.forEach(_contents, (task) { | |
| 442 _schedule._currentTask = task; | |
| 443 if (_error != null) throw _error; | |
| 444 if (_aborted) return null; | |
| 445 | |
| 446 _taskFuture = new SubstituteFuture(task.fn()); | |
| 447 return _taskFuture.whenComplete(() { | |
| 448 _taskFuture = null; | |
| 449 _schedule.heartbeat(); | |
| 450 }).catchError((e, trace) { | |
| 451 var error = new ScheduleError.from(_schedule, e, stackTrace: trace); | |
| 452 _signalError(error); | |
| 453 throw _error; | |
| 454 }); | |
| 455 }).whenComplete(() { | |
| 456 _schedule._currentTask = null; | |
| 457 }).then((_) { | |
| 458 _onTasksCompleteCompleter.complete(); | |
| 459 }).catchError((e, stackTrace) { | |
| 460 _onTasksCompleteCompleter.completeError(e, stackTrace); | |
| 461 throw e; | |
| 462 }).whenComplete(() { | |
| 463 if (pendingCallbacks.isEmpty) return null; | |
| 464 return _noPendingCallbacks.catchError((e, stackTrace) { | |
| 465 // Signal the error rather than passing it through directly so that if a | |
| 466 // timeout happens after an in-task error, both are reported. | |
| 467 _signalError(new ScheduleError.from(_schedule, e, | |
| 468 stackTrace: stackTrace)); | |
| 469 }); | |
| 470 }).whenComplete(() { | |
| 471 _schedule.heartbeat(); | |
| 472 // If the tasks were otherwise successful, make sure we throw any | |
| 473 // out-of-band errors. If a task failed, make sure we throw the most | |
| 474 // recent error. | |
| 475 if (_error != null) throw _error; | |
| 476 }); | |
| 477 } | |
| 478 | |
| 479 /// Stops this queue after the current task and any out-of-band callbacks | |
| 480 /// finish running. | |
| 481 void _abort() { | |
| 482 assert(_schedule.state == ScheduleState.SET_UP || isRunning); | |
| 483 _aborted = true; | |
| 484 } | |
| 485 | |
| 486 /// Returns a function wrapping [fn] that pipes any errors into the schedule | |
| 487 /// chain. This will also block [this] from completing until the returned | |
| 488 /// function has been called. It's used to ensure that out-of-band callbacks | |
| 489 /// are properly handled by the scheduled test. | |
| 490 Function _wrapAsync(fn(arg), String description) { | |
| 491 assert(_schedule.state == ScheduleState.SET_UP || isRunning); | |
| 492 | |
| 493 // It's possible that the queue timed out before [fn] finished. | |
| 494 bool _timedOut() => | |
| 495 _schedule.currentQueue != this || pendingCallbacks.isEmpty; | |
| 496 | |
| 497 _totalCallbacks++; | |
| 498 var chain = new Chain.current(); | |
| 499 var pendingCallback = new PendingCallback._(() { | |
| 500 var fullDescription = description; | |
| 501 if (fullDescription == null) { | |
| 502 fullDescription = "Out-of-band operation #${_totalCallbacks}"; | |
| 503 } | |
| 504 | |
| 505 var stackString = prefixLines(terseTraceString(chain)); | |
| 506 fullDescription += "\n\nStack chain:\n$stackString"; | |
| 507 return fullDescription; | |
| 508 }); | |
| 509 _pendingCallbacks.add(pendingCallback); | |
| 510 | |
| 511 return (arg) { | |
| 512 try { | |
| 513 return fn(arg); | |
| 514 } catch (e, stackTrace) { | |
| 515 var error = new ScheduleError.from( | |
| 516 _schedule, e, stackTrace: stackTrace); | |
| 517 if (_timedOut()) { | |
| 518 _schedule._signalPostTimeoutError(error); | |
| 519 } else { | |
| 520 _schedule.signalError(error); | |
| 521 } | |
| 522 } finally { | |
| 523 if (_timedOut()) return null; | |
| 524 | |
| 525 _pendingCallbacks.remove(pendingCallback); | |
| 526 if (_pendingCallbacks.isEmpty && !isRunningTasks) { | |
| 527 _noPendingCallbacksCompleter.complete(); | |
| 528 } | |
| 529 } | |
| 530 }; | |
| 531 } | |
| 532 | |
| 533 /// Signals that an out-of-band error has been detected and the queue should | |
| 534 /// stop running as soon as possible. | |
| 535 void _signalError(ScheduleError error) { | |
| 536 // If multiple errors are detected while a task is running, make sure the | |
| 537 // earlier ones are recorded in the schedule. | |
| 538 if (_error != null) _schedule._addError(_error); | |
| 539 _error = error; | |
| 540 } | |
| 541 | |
| 542 /// Notifies the queue that it has timed out and it needs to terminate | |
| 543 /// immediately with a timeout error. | |
| 544 void _signalTimeout(ScheduleError error) { | |
| 545 _pendingCallbacks.clear(); | |
| 546 if (!isRunningTasks) { | |
| 547 _noPendingCallbacksCompleter.completeError(error); | |
| 548 } else if (_taskFuture != null) { | |
| 549 // Catch errors coming off the old task future, in case it completes after | |
| 550 // timing out. | |
| 551 _taskFuture.substitute(new Future.error(error)) | |
| 552 .catchError((e, stackTrace) { | |
| 553 _schedule._signalPostTimeoutError(e, stackTrace); | |
| 554 }); | |
| 555 } else { | |
| 556 // This branch probably won't be reached, but it's conceivable that the | |
| 557 // event loop might get pumped when _taskFuture is null but we haven't yet | |
| 558 // finished running all the tasks. | |
| 559 _signalError(error); | |
| 560 } | |
| 561 } | |
| 562 | |
| 563 String toString() => name; | |
| 564 | |
| 565 /// Returns a detailed representation of the queue as a tree of tasks. If | |
| 566 /// [highlight] is passed, that task is specially highlighted. | |
| 567 /// | |
| 568 /// [highlight] must be a task in this queue. | |
| 569 String generateTree([Task highlight]) { | |
| 570 assert(highlight == null || highlight.queue == this); | |
| 571 return _contents.map((task) { | |
| 572 var taskString = task == highlight | |
| 573 ? task.toStringWithStackTrace() | |
| 574 : task.toString(); | |
| 575 taskString = prefixLines(taskString, | |
| 576 firstPrefix: task == highlight ? "> " : "* "); | |
| 577 | |
| 578 if (task == highlight && !task.children.isEmpty) { | |
| 579 var childrenString = task.children.map((child) { | |
| 580 var prefix = ">"; | |
| 581 if (child.state == TaskState.ERROR) { | |
| 582 prefix = "X"; | |
| 583 } else if (child.state == TaskState.SUCCESS) { | |
| 584 prefix = "*"; | |
| 585 } | |
| 586 | |
| 587 var childString = prefix == "*" | |
| 588 ? child.toString() | |
| 589 : child.toStringWithStackTrace(); | |
| 590 return prefixLines(childString, | |
| 591 firstPrefix: " $prefix ", prefix: " | "); | |
| 592 }).join('\n'); | |
| 593 taskString = '$taskString\n$childrenString'; | |
| 594 } | |
| 595 | |
| 596 return taskString; | |
| 597 }).join("\n"); | |
| 598 } | |
| 599 } | |
| 600 | |
| 601 /// A thunk for lazily resolving the description of a [PendingCallback]. | |
| 602 typedef String _DescriptionThunk(); | |
| 603 | |
| 604 /// An identifier for an out-of-band callback running during a schedule. | |
| 605 class PendingCallback { | |
| 606 final _DescriptionThunk _thunk; | |
| 607 String _description; | |
| 608 | |
| 609 /// The string description of the callback. | |
| 610 String get description { | |
| 611 if (_description == null) _description = _thunk(); | |
| 612 return _description; | |
| 613 } | |
| 614 | |
| 615 String toString() => description; | |
| 616 | |
| 617 PendingCallback._(this._thunk); | |
| 618 } | |
| OLD | NEW |
|---|
Chromium Code Reviews
Issue 812253002:
Delete a bunch of packages that are now on GitHub. (Closed)
Base URL: https://dart.googlecode.com/svn/branches/bleeding_edge/dart