static void SomeBoringTask()
{
Pool.WaitOne();
// do something in the task
var item = new CustomClass();
item.AddItems();
item.CreateTempFile();
// have a nap
Thread.Sleep(Random.Next(5000, 10000));
Console.WriteLine("Task {0} finished", item.Id);
// release the semaphore
Pool.Release();
count--;
UpdateMessage();
}