HttpApplicationState - Why does Race condition exist if it is thread safe?

Question

I just read an article that describes how HttpApplicationState has AcquireRead() / AcquireWrite() functions to manage concurrent access. It continues to explain

Answer 1

HttpApplicationState - where the globally access variables those are visible to all the

users who are using the application. So in order to avoid the race condition while changing

the value of the variables. We need some precautionary, thats why we are using

Application.Lock() and after the job done releasing the same variable to others in the

queue using Application.Unlock()

Application.Lock()
Application("VisitorCount") = Convert.ToInt32(Application("VisitorCount")) + 1
Application.UnLock()