> atomic<shared_ptr<T>>::is_lock_free is always true, which is correct.
The attached link shows the opposite, which is the reason i asked this
question in first place.
If we look at the libstdc++ code, it shows this function always returns
false:
https://github.com/gcc-mirror/gcc/blob/master/libstdc%2B%2B-v3/include/bits/shared_ptr_atomic.h#L622
On 8/4/23 11:07, Jonathan Wakely wrote:
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
