// https://stackoverflow.com/questions/46467275/weird-stack-trace-growth-with-async-await-and-taskcompletionsource

using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Runtime.Serialization;
using System.Runtime.Serialization.Formatters.Binary;
using System.Threading;
using System.Threading.Tasks;

namespace BatchErrorWithTcs
{
    class Program
    {
        static readonly List<TaskCompletionSource<bool>> buffer = 
                    new List<TaskCompletionSource<bool>>();
        static Timer timer;

        public static void Main()
        {
            var outstanding = Enumerable.Range(1, 2)
                .Select(Enqueue)
                .ToList();

            timer = new Timer(x => Flush(), null, 
                TimeSpan.FromSeconds(1),
                TimeSpan.FromMilliseconds(-1));

            outstanding.ForEach(WaitExecute);

            Console.ReadKey();
        }

        static void WaitExecute(Task t)
        {
            try
            {
                t.GetAwaiter().GetResult();
            }
            catch (Exception e)
            {
                Console.WriteLine($"Stack Trace:\nLength:{e.StackTrace.Length}\n{e.StackTrace}\n");
            }
        }

        static async Task Enqueue(int i)
        {
            var task = new TaskCompletionSource<bool>();
            buffer.Add(task);
            await task.Task;
        }

        static void Flush()
        {
            try
            {
                Some();
            }
            catch (Exception e)
            {
                foreach (var each in buffer)
                    each.TrySetException(DeepClone(e));
            }
        }

        static void Some() => throw new Exception("test");

        public static T DeepClone<T>(T obj)
        {
          using (var ms = new MemoryStream())
          {
            var formatter = new BinaryFormatter();
            formatter.Serialize(ms, obj);
            ms.Position = 0;

            return (T)formatter.Deserialize(ms);
          }
        }
    }
}