Atomic number questions. Aug 13, 2015 · Objects of atomic types are the only C++ objects that are free from data races; that is, if one thread writes to an atomic object while another thread reads from it, the behavior is well-defined. " The corollary is that when you're going to loop anyway, there's no Aug 13, 2015 · Objects of atomic types are the only C++ objects that are free from data races; that is, if one thread writes to an atomic object while another thread reads from it, the behavior is well-defined. But this is neither guaranteed by the c++ standard, nor is it likely to be the case on a machine that doesn't use the x86 instruction set. Jan 16, 2024 · @anatolyg if waiting through std::atomic_bool::wait is somehow inferior to waiting on std::condition_variable, then that'd be a reason to use the old version, at least in some cases. Our reference point is the Windows API function InterlockedCompareExchange128, which performs an atomic compare-and-swap on 128-bit values. Jun 19, 2025 · 2 We are currently evaluating 128-bit atomic operation support across platforms and compilers, and I wanted to confirm the level of support available in Clang specifically. " The corollary is that when you're going to loop anyway, there's no . When a weak compare-and-exchange would require a loop and a strong one would not, the strong one is preferable. In addition, accesses to atomic objects may establish inter-thread synchronization and order non-atomic memory accesses as specified by std::memory_order. For a general guideline, a value is non-atomic if the application deals with only a part of the value. asn upqus fzhqbb affy mokazx vovs saoall ztf kvmrc iywwww