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Does std::mutex enforce cache cohesion?

zongcailala 注册会员
2023-01-26 01:46

C++ operates on the relations between operations not some particular hardware terms (like cache cohesion). So C++ Standard has a happens-before relationship which roughly means that whatever happened before completed all its side-effects and therefore is visible at the moment that happened after.

And given you have an exclusive critical session to which you have entered means that whatever happens within it, happens before the next time this critical section is entered. So any consequential entering to it will see everything happened before. That's what the Standard mandates. Everything else (including the cache cohesion) is the implementation's duty: it has to make sure that the described behavior is coherent with what actually happens.