sample of c# async usage

AboutAsyncMain.cs

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

namespace FunctionalExperiments
{
    class AboutAsyncMain
    {
        static void Main(string[] args)
        {
            var runner = new AboutAsync();
            long time = Systime();
            int count = 3;
            var tasks = new List<Task>(count);

            for (int i = 0; i < count; i++)
            {
               Task t = runner.AsyncCall(BlockingFunction,$"val={i}");
               tasks.Add(t);
            }

            tasks.ForEach((t) =>
            {
                t.Wait();
            });

            time = Systime() - time;
            Console.WriteLine($"time is: {time}");
            Console.ReadKey();
        }

        static void BlockingFunction(String val)
        {
            Thread.Sleep(1000);
            Console.WriteLine($"executed {val}");
        }

        static long Systime()
        {
            return DateTimeOffset.Now.ToUnixTimeMilliseconds();
        }
    }

    class AboutAsync
    {
        public delegate void BFCall(String val);

        public async Task AsyncCall(BFCall call, String val)
        {            
            await Task.Run(()=>
            {
                call(val);
            });
        }
    }
}