This paper introducing generalizations of LLS and SC could be interesting, also to implement those with CAS-only systems.   -----Ursprüngliche Nachricht----- Von:connor horman via Std-Proposals <std-proposals_at_[hidden]> Gesendet:Mo 22.07.2024 13:51 Betreff:Re: [std-proposals] Abstraction for load-linked/store-conditional An:std-proposals_at_[hidden]; CC:connor horman <chorman64_at_[hidden]>; LL/SC is also hard to abstract over. I don't know how it is for ARM, but on RISC-V there are very strong restrictions about what you can actually do between the LL and SC (or the SC will uncontionally fail) - one of which is no branches, so the abstraction basically requires inlining to happen (or otherwise, is allowed to reliably fail for no reason - not fail spuriously, because spurious implies that the failure isn't reliable). On Mon, 22 Jul 2024 at 07:28, Jonathan Wakely via Std-Proposals <std-proposals_at_[hidden] <mailto:std-proposals_at_[hidden]> > wrote:   On Mon, 22 Jul 2024 at 08:00, Jens Maurer via Std-Proposals <std-proposals_at_[hidden] <mailto:std-proposals_at_[hidden]> > wrote: On 22/07/2024 00.23, Joseph Schuchart via Std-Proposals wrote: > I'm not sure that this API could be implemented everywhere And here's the problem: I don't know how you can provide ABA avoidance if all your hardware has is atomic compare-and-swap. So, this doesn't really help write portable programs. We have rather few features in C++ that aren't available on all implementations, so the introduction of such a non-portable feature needs additional rationale.  And for better or for worse, "not supported on x86" is likely to need a lot more rationale than "not supported on AVR" (for example).    (There are plenty of hardware features that aren't available everywhere, yet we strive to make C++ interfaces on them that can be implemented everywhere, e.g. std::simd.) Jens -- Std-Proposals mailing list Std-Proposals_at_[hidden] <mailto:Std-Proposals_at_[hidden]> https://lists.isocpp.org/mailman/listinfo.cgi/std-proposals -- Std-Proposals mailing list Std-Proposals_at_[hidden] https://lists.isocpp.org/mailman/listinfo.cgi/std-proposals