Comment by BeeOnRope

You don't even need to read the whole article to see the GP's point: the very first example with flag_ is concurrent, unsynchronized access to a shared volatile, and the article promotes it as "the right way".

Yes, it goes on to elaborate on a basically unrelated use of volatile to control access to member functions on classes, which deserves a separate discussion - but you don't even need to get past the first few paragraphs to see that it promulgates the idea that broken makes concurrent access safe. It doesn't.