using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading;
using System.Threading.Tasks;

namespace ConsoleApp22
{
    class Program
    {
        internal class WorkTasksState
        {
            private int _inProgress = 0;
            public void AddTask() => Interlocked.Increment(ref _inProgress);
            public void SignalComplete() => Interlocked.Decrement(ref _inProgress);
            public bool AllDone => _inProgress == 0;
            public async Task WaitComplete()
            {
                while (!AllDone)
                {
                    await Task.Delay(1);
                }
            }
        }
        static async Task Main()
        {
            while (true)
            {
                Console.WriteLine("Loop");
                WorkTasksState state = new();
                for(int i = 0; i < 2048; i++)
                {
                    state.AddTask();
                    ThreadPool.QueueUserWorkItem(Foo, state);
                }
                await state.WaitComplete();
            }
        }
        private static async void Foo(object? state)
        {
            var s = state as WorkTasksState;
            Console.WriteLine($"Start Foo  in {Thread.CurrentThread.ManagedThreadId}");
            Random rnd = new();
            List<byte[]> temp = new();
            for(int i = 0; i < 1024; i++)
            {
                await Task.Yield();
                byte[] buffer = new byte[1024];
                temp.Add(buffer);
            }
            List<decimal> sums = new();
            foreach(var item in temp)
            {
                await Task.Yield();
                rnd.NextBytes(item);
                var sum = item.Sum(x=>x);
                sums.Add(sum);
            }
            //Раскоментируй и сравни
            //GC.Collect();
            Console.WriteLine($"Complete in {Thread.CurrentThread.ManagedThreadId}");
            s.SignalComplete();
        }
    }
}