On Tue, Aug 4, 2015 at 11:50 AM, Amit Kapila <amit.kapila16@gmail.com> wrote:
> I have kept barriers based on comments on top of atomic read, refer
> below code:
>
> * No barrier semantics.
> */
> STATIC_IF_INLINE uint32
> pg_atomic_read_u32(volatile pg_atomic_uint32 *ptr)
>
> Note - The function header comments on pg_atomic_read_u32 and
> corresponding write call seems to be reversed, but that is something
> separate.
That doesn't matter, because the compare-and-exchange *is* a barrier.
Putting a barrier between a store and an operation that is already a
barrier doesn't do anything useful.
--
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company
