using System;

using System.Collections.Concurrent;

using System.Threading;

using System.Threading.Tasks;

using System.Diagnostics;

​

public class Program

{

    public static void Main()

    {

        new Thread(() =>

        {

            var queue = new BlockingCollection<int>();

            Parallel.ForEach(queue.GetConsumingEnumerable(), _ => { });

        })

        { IsBackground = true }.Start();

​

        Stopwatch stopwatch = Stopwatch.StartNew();

        while (true)

        {

            Console.WriteLine($"ThreadCount: {ThreadPool.ThreadCount}");

            if (stopwatch.ElapsedMilliseconds > 8000) break;

            Thread.Sleep(1000);

        }

        Console.WriteLine("Finished");

    }

}

​