Interlocked and Memory Barriers

Question

I have a question about the following code sample (m_value isn\'t volatile, and every thread runs on a separate processor)

void Foo() // executed by thr         


        

Answer 1

The interlocked exchange operations guarantee a memory barrier.

The following synchronization functions use the appropriate barriers to ensure memory ordering:

• Functions that enter or leave critical sections

• Functions that signal synchronization objects

• Wait functions

• Interlocked functions

(Source : link)

But you are out of luck with register variables. If m_value is in a register in Bar, you won't see the change to m_value. Due to this, you should declare shared variables 'volatile'.