C , C++ unsynchronized threads returning a strange result

Question

Okay, i have this question in one regarding threads.

there are two unsynchronized threads running simultaneously and using a global resource \"int num\" 1st:

Answer 1

As Thomas said, the results are unpredictable because your increment and decrement are non-atomic. You can use InterlockedIncrement and InterlockedDecrement -- which are atomic -- to see a predictable result.

• Interlocked Variable Access (MSDN)