As you can see, std::memory_order_release ensures that the write behavior after it does not occur before the release operation, which is a backward barrier, andstd::memory_order_acquire ensures that its previous write behavior does not occur after this acquisition operation, there is a forward barrier. 

As you can see, std::memory_order_release ensures that the load/store before it does not occur after the release operation, which is a forward barrier, and std::memory_order_acquire ensures that load/store after it does not occur before this acquisition operation, that is a backward barrier. 

可以看到，std::memory_order_release 确保了它之后的写行为不会发生在释放操作之前，是一个向后的屏障，而 std::memory_order_acquire 确保了它之前的写行为，不会发生在该获取操作之后，是一个向前的屏障。

可以看到，std::memory_order_release 确保了它之前的读写行为不会发生在释放操作之后，是一个向前的屏障，而 std::memory_order_acquire 确保了它之后的读写行为，不会发生在该获取操作之前，是一个向后的屏障。