using System;

using System.Linq;

using System.Threading;

using System.Threading.Tasks;

using System.Threading.Tasks.Dataflow;

​

public class Program

{

    public static async Task Main()

    {

        var xlsBlock = new TransformBlock<int, int>(document =>

        {

            int duration = 300 + document % 3 * 300;

            Thread.Sleep(duration); // Simulate CPU-bound work

            return document;

        });

        var pdfBlock = new TransformBlock<int, int>(document =>

        {

            int duration = 100 + document % 5 * 200;

            Thread.Sleep(duration); // Simulate CPU-bound work

            return document;

        });

​

        var uploader = new ActionBlock<int>(async document =>

        {

            Console.WriteLine("Uploading document #{0}", document);

            await Task.Delay(500); // Simulate I/O-bound work

        });

​

        xlsBlock.LinkTo(uploader);

        pdfBlock.LinkTo(uploader);

​

        foreach (var document in Enumerable.Range(1, 10))

        {

            if (document % 2 == 0)

                xlsBlock.Post(document);

            else

                pdfBlock.Post(document);

        }

        xlsBlock.Complete();

        pdfBlock.Complete();

        _ = Task.WhenAll(xlsBlock.Completion, pdfBlock.Completion)

            .ContinueWith(_ => uploader.Complete());

​

        await uploader.Completion;

    }

}