using System;

using System.Linq;

using System.Threading;

using System.Threading.Tasks;

public class Program

{

    public static void Main()

    {

        var task = Task.Delay(500);

        var workers = Enumerable.Range(1, 4).Select(async x =>

        {

            Console.WriteLine($"{DateTime.Now:HH:mm:ss.fff}" +

                $" [{Thread.CurrentThread.ManagedThreadId}] Worker{x} before await");

​

            await task;

            //await Task.WhenAll(task);

​

            Console.WriteLine($"{DateTime.Now:HH:mm:ss.fff}" +

                $" [{Thread.CurrentThread.ManagedThreadId}] Worker{x} after await");

​

            Thread.Sleep(1000); // Simulate some heavy CPU-bound computation

        }).ToArray();

        Task.WaitAll(workers);

    }

}