using System;
using System.Collections.Generic;
using System.Net.NetworkInformation;
using System.Threading;
using System.Threading.Tasks;

public class Example
{
    public static void Main()
    {
        int failed = 0;
        var tasks = new List<Task>();
        String[] urls = { "www.adatum.com", "www.cohovineyard.com",
                        "www.cohowinery.com", "www.northwindtraders.com",
                        "www.contoso.com" };

        foreach (var value in urls)
        {
            var url = value;
            tasks.Add(Task.Run(() => {
                var png = new Ping();
                try
                {
                    var reply = png.Send(url);
                    if (!(reply.Status == IPStatus.Success))
                    {
                        Interlocked.Increment(ref failed);
                        throw new TimeoutException("Unable to reach " + url + ".");
                    }
                }
                catch (PingException)
                {
                    Interlocked.Increment(ref failed);
                    throw;
                }
            }));
        }
        Task t = Task.WhenAll(tasks);
        try
        {
            t.Wait();
        }
        catch { }

        if (t.Status == TaskStatus.RanToCompletion)
            Console.WriteLine("All ping attempts succeeded.");
        else if (t.Status == TaskStatus.Faulted)
            Console.WriteLine("{0} ping attempts failed", failed);
    }
}