如何获取异步执行的完整堆栈跟踪

Question

举个小例子

import 'dart:async';
import 'package:stack_trace/stack_trace.dart';

void main() {
  scheduleAsync();
}

void scheduleAsync() {
  new Future.delayed(new Duration(seconds: 1))
      .then((_) => runAsync());
}

void runAsync() {
  throw 'oh no!';
}

我得到了这个堆栈跟踪。我能追踪到的最远的回调是 scheduleAsync() 中的 runAsync() 调用。没有留下任何信息，scheduleAsync 是从 main.

调用的

未处理的异常：
未捕获的错误：哦不！
堆栈跟踪：
#0 runAsync (文件:///home/myuser/dart/playground/bin/stack_trace/main.dart:14:3)
#1 scheduleAsync。 (文件:///home/myuser/dart/playground/bin/stack_trace/main.dart:10:28)
#2 _RootZone.runUnary（飞镖：async/zone.飞镖：1155）
#3 _Future._propagateToListeners.handleValueCallback（飞镖：async/future_impl.飞镖：484）
#4 _Future._propagateToListeners（飞镖：async/future_impl.飞镖：567）
#5 _Future._complete（飞镖：async/future_impl.飞镖：348）
#6 Future.Future.delayed。 (飞镖:async/future.飞镖:228)
#7 Timer._createTimer。 (飞镖:async-patch/timer_patch.飞镖:16)
#8 _Timer._runTimers（飞镖：isolate-patch/timer_impl.飞镖：385）
#9 _handleMessage (飞镖:isolate-patch/timer_impl.飞镖:411)
#10 _RawReceivePortImpl._handleMessage（飞镖：isolate-patch/isolate_patch.飞镖：142）

#0 _rootHandleUncaughtError。 (飞镖:async/zone.飞镖:886)
#1 _asyncRunCallbackLoop (飞镖:async/schedule_microtask.飞镖:41)
#2 _asyncRunCallback (飞镖:async/schedule_microtask.飞镖:48)
#3 _runPendingImmediateCallback（飞镖：isolate-patch/isolate_patch.飞镖：96）
#4 _Timer._runTimers（飞镖：isolate-patch/timer_impl.飞镖：392）
#5 _handleMessage (飞镖:isolate-patch/timer_impl.飞镖:411)
#6 _RawReceivePortImpl._handleMessage（飞镖：isolate-patch/isolate_patch.飞镖：142）

进程结束，退出代码为 255

有没有办法获得完整的堆栈跟踪？

Answer 1

stack_trace 包 https://pub.dartlang.org/packages/stack_trace 将整个堆栈跟踪放在一起。

另见
- this blog post 来自 stack_trace 包的开发者。
- http://news.dartlang.org/2016/01/unboxing-packages-stacktrace.html?m=1

import 'dart:async';
import 'package:stack_trace/stack_trace.dart';

void main() {
  Chain.capture(() {
    scheduleAsync(); // <= pass my code in Chain.capture
    }, onError: (error, stack) {
      print(error);
      print(stack);
    });
}

void scheduleAsync() {
  new Future.delayed(new Duration(seconds: 1))
      .then((_) => runAsync());
}

void runAsync() {
  throw 'oh no!';
}

生成此输出，允许追溯到 main 中的第一行。

oh no!
main.dart 19:3                                                runAsync
main.dart 15:28                                               scheduleAsync.
package:stack_trace/src/stack_zone_specification.dart 134:26  registerUnaryCallback..
package:stack_trace/src/stack_zone_specification.dart 210:15  StackZoneSpecification._run
package:stack_trace/src/stack_zone_specification.dart 134:18  registerUnaryCallback.
dart:async/zone.dart 902                                      _rootRunUnary
dart:async/zone.dart 804                                      _CustomZone.runUnary
dart:async/future_impl.dart 484                               _Future._propagateToListeners.handleValueCallback
dart:async/future_impl.dart 567                               _Future._propagateToListeners
dart:async/future_impl.dart 348                               _Future._complete
dart:async/future.dart 228                                    Future.Future.delayed.
package:stack_trace/src/stack_zone_specification.dart 210:15  StackZoneSpecification._run
package:stack_trace/src/stack_zone_specification.dart 124:52  registerCallback.
dart:async/zone.dart 891                                      _rootRun
dart:async/zone.dart 796                                      _CustomZone.run
dart:async/zone.dart 704                                      _CustomZone.runGuarded
dart:async/zone.dart 729                                      _CustomZone.bindCallback.
package:stack_trace/src/stack_zone_specification.dart 210:15  StackZoneSpecification._run
package:stack_trace/src/stack_zone_specification.dart 124:52  registerCallback.
dart:async/zone.dart 895                                      _rootRun
dart:async/zone.dart 796                                      _CustomZone.run
dart:async/zone.dart 704                                      _CustomZone.runGuarded
dart:async/zone.dart 729                                      _CustomZone.bindCallback.
dart:async-patch/timer_patch.dart 16                          Timer._createTimer.
dart:isolate-patch/timer_impl.dart 385                        _Timer._runTimers
dart:isolate-patch/timer_impl.dart 411                        _handleMessage
dart:isolate-patch/isolate_patch.dart 142                     _RawReceivePortImpl._handleMessage
===== asynchronous gap ===========================
dart:async/zone.dart 828                                      _CustomZone.registerUnaryCallback
dart:async/future_impl.dart 208                               _Future.then
main.dart 15:12                                               scheduleAsync
main.dart 6:18                                                main.
package:stack_trace/src/chain.dart 82:24                      Chain.capture.
dart:async/zone.dart 895                                      _rootRun
dart:async/zone.dart 796                                      _CustomZone.run
dart:async/zone.dart 1251                                     runZoned
package:stack_trace/src/chain.dart 80:20                      Chain.capture
main.dart 5:16                                                main
dart:isolate-patch/isolate_patch.dart 255                     _startIsolate.
dart:isolate-patch/isolate_patch.dart 142                     _RawReceivePortImpl._handleMessage


Process finished with exit code 0

更有用的是简洁的版本

import 'dart:async';
import 'package:stack_trace/stack_trace.dart';

void main() {
  Chain.capture(() {
    scheduleAsync();
    }, onError: (error, stack) {
      print(error);
      print(new Trace.from(stack).terse);
    });
}

void scheduleAsync() {
  new Future.delayed(new Duration(seconds: 1))
      .then((_) => runAsync());
}

void runAsync() {
  throw 'oh no!';
}

产生：

oh no!
main.dart 19:3       runAsync
main.dart 15:28      scheduleAsync.
===== asynchronous gap ===========================
dart:async           _Future.then
main.dart 15:12      scheduleAsync
main.dart 6:18       main.
package:stack_trace  Chain.capture
main.dart 5:16       main


Process finished with exit code 0

如何获取异步执行的完整堆栈跟踪

How to get the full stack trace for async execution

dart

dart-async