3 ms·

Wouldn't that depend on the case? There is a nonzero amount of things in the universe for which volatile with no locking will do. Although, any particular thin

• ncmncm 7y ago
  This definitely wasn't one. It didn't bite in any obvious way because Intel, and because the system already had so many other bugs. (Free advice: don't take on a C++ program written by a Java coder.)
• legulere 7y ago
  Volatile doesn’t even guarantee that data is written atomically in one step and not e.g. byte-wise. Also it allows both the compiler as well as the CPU to reorder it with any read or write. I can’t think of anything that would it could be used for in a multithreaded environment.
  • ncmncm 7y ago
    Right. There is really only a single place volatile actually works, and that is for memory-mapped hardware registers. Anybody who says it is useful for anything else is badly mistaken. Except in MSVC, where it kinda/sorta means atomic.
  • rcxdude 7y ago
    It allows the compiler to reorder it with any non-volatile read or write. Of course it still doesn't indicate anything to the CPU. In single-core embedded systems where the CPU doesn't reorder anything and you know the compiler is going to emit a single instruction for a read or write it can be sufficient (for example, this is how FreeRTOS implements all of its threading primitives)