using System;

using System.Collections.Generic;

using System.Threading.Tasks;

public class Program

{

    public void Main()

    {

        PackageView packageView = null;

        var executes = new List<Func<Task>>(2);

        executes.Add(new Func<Task>(async () =>

                     {

                         await CreateAuditAccess();

                     }));

        executes.Add(new Func<Task>(async () =>

                     {

                         packageView = await GetPackageView();

                     }));

        WhenAll(executes).GetAwaiter().GetResult();

        Console.WriteLine("All went well");

    }

    public static async Task CreateAuditAccess()

    {

        await Task.Delay(5000).ConfigureAwait(false);

        //throw new Exception("AuditException");

    }

    public static async Task<PackageView> GetPackageView()

    {

        await Task.Delay(5000).ConfigureAwait(false);

        throw new Exception("PackageView Exception");

        return new PackageView();

    }

    public static async Task WhenAll(List<Func<Task>> execute, byte concurrency = 50)

    {

        var taskBuffer = new List<Task>(concurrency);

            if (execute.Count <= concurrency)

            {

                foreach (var executor in execute)

                {

                    taskBuffer.Add(executor());

                }

​

                await Task.WhenAll(taskBuffer).ConfigureAwait(false);

            }

​

            int completed = 0;

            int inputPosition = concurrency;

            for (int index = 0; index < concurrency; index++)

            {

                taskBuffer.Add(execute[index]());

            }

            while (execute.Count > completed)

            {

                var completedTask = await Task.WhenAny(taskBuffer).ConfigureAwait(false);

​

                taskBuffer.Remove(completedTask);

                completed++;

                await completedTask;

​

                if (inputPosition < execute.Count)

                {

                    taskBuffer.Add(execute[inputPosition]());

                    inputPosition++;

                }

            }

    }

}

​

public class Output

{

    public bool Result {get; set; }

    public Exception Exception {get; set; }

}

​

public class PackageView

{

}