Is frequently updating std::atomic

Problem

• Assume static std::atomic<double> dataX =0.0; defined in a cpp(Module)
• In that module two separate functions have been defined.
• These functions will be invoked and run by two threads independently,under the hood(within functions) two continuous looping processes are defined there; until
  some break statement gets called(using predicate).
• When the two functions are running one function responsible for writing data todataX and other function responsible for reading from dataX and then post it to a container.
• These two execution of functions happen under two threads as described and each thread gets sleep for very tiny millisecond(1ms) of duration.
• Therefore both Read/Write operations for dataX coupled and gets called within very less amount of CPU cycle time.

How does C/C++ run-time behave such condition for std::atomic<double> ?

Can we have a guarantee about both written and read values of std::atomic<double> dataX maintained such condition?