如何对具有最新上下文的多个并发任务执行一次取消/异常清理？

问：

我正在编写一个桌面应用程序来控制一个小型 XY 阶段，遵循 MVP 架构。有一个 UI 线程，该线程发送到使用它们的 Operation 线程，并执行实际控制。Operation 线程在使用新事件时并发运行其硬件控制逻辑。存在覆盖当前任务（例如停止然后开始执行）的一个或多个新事件的情况。我希望能够取消任务、执行特定的清理和处理错误，例如使用操作线程中提供的最新上下文。ViewEventViewEvent.StopViewEvent.MoveRightViewEvent.MoveLeftViewEventLostConnectionException

我尝试运行一个循环，该循环从 a 读取并执行 's without 并利用它来处理取消/失败清理。生成任务的业务逻辑将在 Presenter 内部执行。asyncBlockingCollection<ViewEvent>async TaskawaitTask.ContinueWith

public async Task HandleEventsBlocking()
{
    foreach (var viewEvent in _viewEventsQueue.GetConsumingEnumerable())
    {
        switch (viewEvent)
        {
            case ViewEvent.Start:
                Presenter.HandleStartAsync(_cts.Token).ContinueWith((task) =>
                {
                    if (task.IsFaulted)
                    {
                        // Clean up and cancel all other tasks.
                        foreach (var innerException in task.Exception.InnerExceptions)
                        {
                            Console.WriteLine($"Caught exception: {innerException.Message}");
                        }
                        _cts.Cancel();
                    }
                    else if (task.IsCanceled)
                    {
                        // Clean up.
                        await Presenter.CleanUp();
                    }
                });
                break;
            case ViewEvent.Faulty:
                Presenter.HandleFaultyAsync(_cts.Token).ContinueWith((task) =>
                {
                    if (task.IsFaulted)
                    {
                        // Clean up and cancel all other tasks.
                        foreach (var innerException in task.Exception.InnerExceptions)
                        {
                            Console.WriteLine($"Caught exception: {innerException.Message}");
                        }
                        _cts.Cancel();
                    }
                    else if (task.IsCanceled)
                    {
                        // Clean up.
                        await Presenter.CleanUp();
                    }

                });
                break;
            case ViewEvent.Stop:
                _cts.Cancel();
                break;
            case ViewEvent.Reset:
                _cts.Dispose();
                _cts = new CancellationTokenSource();
                break;
        }
    }
}

public async Task HandleStartAsync(CancellationToken token)
{
    await Task.Run(async () =>
    {
        token.ThrowIfCancellationRequested();
        await Task.Delay(2000); // Simulated work. Would be passed token.
        token.ThrowIfCancellationRequested();
    });
}

public async Task HandleFaultyAsync(CancellationToken token)
{
    await Task.Run(async () =>
    {
        token.ThrowIfCancellationRequested();
        await Task.Delay(2000); // Simulated work that failed. Would be passed token.
        throw new InvalidOperationException("FAILED ON PURPOSE");
    });
}

但是，这种方法不起作用，因为每个人都可能会执行重复的清理工作。async Task

将添加一个额外的布尔标志，该标志在 之前运行，并在所有执行时使用 退出，然后执行清理。该标志将因失败而设置一次，随后将跳过设置它。PerformCleanUpswitchTask.WaitAllasync TaskTaskContinueWith