using System.Collections.Generic;
using System.Threading.Tasks;
public static void Main()
var dealIds = new List<int>();
for(var i=0; i < 100; i++)
List<Task> tasks = new List<Task>();
foreach(var dealId in dealIds){
tasks.Add(Task.Run( () => {
Console.WriteLine("WELCOME : " + dealId);
Task.WaitAll( tasks.ToArray() );
tasks = new List<Task>();
Console.WriteLine("***********************************************************");