AsyncSemaphore\Program001.cs

using System;
using System.Linq;
using System.Threading.Tasks;
using Microsoft.WindowsAzure.Storage;
using Microsoft.WindowsAzure.Storage.Table;

namespace AsyncSemaphore
{
    partial class Program
    {
        static void InsertAsync001(CloudTable table, int start, int count)
        {
            var tasks = Enumerable.Range(start, count).Select(async i =>
            {
                var e = new TableEntity(PKEY_STRS[i % PKEY_STRS.Length], i.ToString("D10"));

                var insertOperation = TableOperation.Insert(e);
                try
                {
                    await table.ExecuteAsync(insertOperation).ConfigureAwait(false);

                    if (i != 0 && i % 100000 == 0)
                        Console.Error.WriteLine(i);
                }
                catch (StorageException se)
                {
                    Console.Error.WriteLine("{0}, {1}", i, se.ToString());
                }
            }).ToArray();

            Task.WhenAll(tasks);
        }
    }
}