On Thu, 3 Aug 2023, 14:35 Bogdan Sinitsyn, <f1u77y@xxxxxxxxx> wrote: > std::atomic<std::shared_ptr<T>> operations seem to generate lock-free > code without _Sp_locker and mutexes, while > std::atomic_*(std::shared_ptr<T>*) operations use _Sp_locker. But > std::atomic_is_lock_free and std::atomic::is_lock_free > show exactly the opposite. Not always. atomic<shared_ptr<T>>::is_lock_free is always true, which is correct. atomic_is_lock_free(shared_ptr<T>*) is true in a single threaded program, false otherwise. If the program is not linked to libpthread then no locking is used (or needed) for the atomic_xxx(shared_ptr*,...) overloads. Maybe I don't interpret that correctly? What > does that supposed to mean? > > https://godbolt.org/z/818v6sMGb > > -- > > Bogdan Sinisyn > >
