public void AddToCount() { var tasks = new List <Task>(); for (int i = 0; i < 1000; i++) { for (int j = 0; j < 10; j++) { tasks.Add( Task.Factory.StartNew((() => Server.GetCount()))); } tasks.Add( Task.Factory.StartNew(() => Server.AddToCount(1))); } Task.WaitAll(tasks.ToArray()); Assert.AreEqual(1000, Server.GetCount()); }