notifyError method

@protected void notifyError(Object error, StackTrace stackTrace)

Announces error and asks for an answer to it.

For the errors that have nowhere else to go: an action abandoned by JobContext.abandonable failing later, a disposer, a callback of JobContext.onCancel, Job.whenCancelled or Job.whenFinished, work handed over with JobContext.unattended. The observer hears it through JobObserver.onError, and one that is a JobAnswerer answers for it through JobAnswerer.onUnanswered; without such an observer the error goes to the zone the job was created in.

Two calls, each guarded on its own: an onError that throws does not cost the error its answer. Both go by the walk of Job.visitErrors: onError is told about each error inside a ParallelWaitError on its own, and the answer is asked for each failure.

A cancellation — a Cancelled, or a ParallelWaitError carrying nothing but cancellations — never reaches the zone from here, and nobody is asked to answer for it: it is a decision somebody made, not a failure. An observer hears it through onError; without one, nobody does. Nor is anybody asked about a failure that Job.isCancellationError names, once the job has accepted a cancellation.

Which failures go on to the answer is settled before onError hears any of them, and onError is told so: JobErrorAnswer.answered for each of those, JobErrorAnswer.cancellation for a cancellation and for a failure the filter names.

See Where each error goes on the error rules page.

Implementation

@protected
void notifyError(Object error, StackTrace stackTrace) {
  final verdicts = _verdicts(error, stackTrace);
  // A failure the walk that took the verdicts did not meet is asked about
  // by nobody.
  _notifyObserver(
    error,
    stackTrace,
    verdicts: verdicts,
    otherwise: JobErrorAnswer.never,
  );
  _askForAnswers(error, verdicts);
}