using System;

using System.Threading;

using System.Threading.Tasks;

using System.Threading.Tasks.Dataflow;

​

static class Program

{

    public static void Main()

    {

        var block1 = new TransformBlock<char, char>(item =>

        {

            Console.WriteLine($"Block-1 processing {item}");

            return item;

        });

​

        var block2 = new TransformBlock<char, char>(item =>

        {

            Console.WriteLine($"Block-2 processing {item}");

            Thread.Sleep(200);

            return item;

        });

​

        var block3 = new ActionBlock<char>(item =>

        {

            Console.WriteLine($"Block-3 processing {item}");

            Thread.Sleep(100);

            throw new Exception();

        });

​

        block1.LinkTo(block2, new() { PropagateCompletion = true });

        block2.PropagateFailure(block1);

​

        block2.LinkTo(block3, new() { PropagateCompletion = true });

        block3.PropagateFailure(block2);

​

        block1.Post('A');

        block1.Post('B');

        block1.Complete();

​

        Task whenAll = Task.WhenAll(block1.Completion, block2.Completion, block3.Completion);

        try { whenAll.Wait(1000); } catch { }

        Console.WriteLine("Task.WhenAll " + (whenAll.IsCompleted ? "Completed" : "Timed-out"));

    }

    static async void PropagateFailure(this IDataflowBlock block1, IDataflowBlock block2)

    {

        try { await block1.Completion.ConfigureAwait(false); } catch { }

        if (block1.Completion.IsFaulted) block2.Fault(block1.Completion.Exception);

    }

}