Reading interlocked variables

Question

Assume:

A. C++ under WIN32.

B. A properly aligned volatile integer incremented and decremented using InterlockedIncrement() and Interlocke

Answer 1

The Interlocked* functions prevent two different processors from accessing the same piece of memory. In a single processor system you are going to be ok. If you have a dual-core system where you have threads on different cores both accessing this value, you might have problems doing what you think is atomic without the Interlocked*.