Locks access to an System.Web.HttpApplicationState variable to facilitate access synchronization.
The System.Web.HttpApplicationState class performs automatic locking and unlocking with the HttpApplicationState.AllKeys and HttpApplicationState.Count properties and the HttpApplicationState.Add(string, object), HttpApplicationState.Clear, erload:System.Web.HttpApplicationState.Get, HttpApplicationState.GetKey(int), HttpApplicationState.Remove(string), HttpApplicationState.RemoveAt(int) and HttpApplicationState.Set(string, object) methods. However, explicitly using the HttpApplicationState.Lock and HttpApplicationState.UnLock methods when you have a series of operations may be more efficient.