using System;

using System.Threading;

using System.Threading.Tasks;

​

public static class Program

{

    public static void Main()

    {

        CancellationToken token = new(canceled: true);

​

        Task taskA = TaskRun2(async () => token.ThrowIfCancellationRequested());

        Task taskB = TaskRun2(async () => token.ThrowIfCancellationRequested(), token);

        try { Task.WaitAll(taskA, taskB); } catch { }

        Console.WriteLine($"taskA.Status: {taskA.Status}");

        Console.WriteLine($"taskB.Status: {taskB.Status}");

    }

​

    /// <summary>

    /// Queues the specified work to run on the thread pool, and returns a proxy

    /// for the task returned by the action. The cancellation behavior is the same

    /// with the Task.Run(Action, CancellationToken) method.

    /// </summary>

    public static Task TaskRun2 (Func<Task> action,

        CancellationToken cancellationToken = default)

    {

        ArgumentNullException.ThrowIfNull(action);

        return Task.Run(action, cancellationToken).ContinueWith(t =>

        {

            if (t.IsCanceled)

            {

                CancellationToken taskToken = new TaskCanceledException(t).CancellationToken;

                if (taskToken != cancellationToken)

                    return Task.FromException(new OperationCanceledException(taskToken));

            }

            return t;

        }, CancellationToken.None, TaskContinuationOptions.DenyChildAttach |

            TaskContinuationOptions.ExecuteSynchronously,

            TaskScheduler.Default).Unwrap();

    }

​

}

​