带任务取消机制的有序任务队列实现方案可行性咨询

我需要实现一个按顺序执行的任务队列，核心要求是：

• 添加新任务时，立即取消队列中当前正在执行的所有任务
• 新任务必须等被取消的任务完全结束（包括处理取消后的逻辑）后，才能启动执行

举个场景例子：先加入一个耗时5秒的task1，1秒后再加入task2，此时需要先触发task1的取消操作，等task1彻底完成取消流程后，再启动task2。

我基于一段现有代码做了适配，添加了上述取消相关的逻辑，想请教这个方案是否可行：

public sealed class ExecutionQueue
{
    private readonly BlockingCollection<Func<Task>> _queue = new BlockingCollection<Func<Task>>();
    private CancellationTokenSource? _cancellationTokenSource;

    public ExecutionQueue() => Completion = Task.Run(() => ProcessQueueAsync());

    public Task Completion { get; }

    public void Complete() => _queue.CompleteAdding();

    private async Task ProcessQueueAsync()
    {
        foreach (var value in _queue.GetConsumingEnumerable())
            await value();
    }

    public Task Run(Func<CancellationToken, Task> lambda)
    {
        if (_cancellationTokenSource != null)
        {
            _cancellationTokenSource.Cancel();
            _cancellationTokenSource.Dispose();
        }

        _cancellationTokenSource = new CancellationTokenSource();

        var tcs = new TaskCompletionSource<object>();
        _queue.Add(async () =>
        {
            try
            {
                await lambda(_cancellationTokenSource.Token);
                tcs.TrySetResult(null);
            }
            catch (OperationCanceledException ex)
            {
                tcs.TrySetCanceled(ex.CancellationToken);
            }
            catch (Exception ex)
            {
                tcs.TrySetException(ex);
            }
        }, _cancellationTokenSource.Token);
        return tcs.Task;
    }
}

示例用法：

public partial class MainWindow : Window
{
    private ExecutionQueue _queue = new ExecutionQueue();

    public MainWindow()
    {
        DataContext = this;
        InitializeComponent();
    }

    int count = 0;

    private void Button_Click(object sender, RoutedEventArgs e)
    {
        int v = count++;

        _queue.Run(async (c) =>
        {
            try
            {
                Debug.WriteLine($"{v} started");
                await Task.Delay(3000, c);
                Debug.WriteLine($"{v} completed");
            }
            catch (OperationCanceledException)
            {
                Debug.WriteLine($"{v} cancelled");
            }
        });
    }
}

内容的提问来源于stack exchange，提问作者wforl