Andres Freund <and...@2ndquadrant.com> writes: > On 2014-06-26 14:13:07 -0700, Tom Lane wrote: >> Surely it had better be a read barrier as well?
> I don't immediately see why it has to be read barrier? Hoisting a load > from after the release into the locked area of code should be safe? No doubt, but delaying a read till after the unlocking write would certainly not be safe. AFAICT, README.barrier completely fails to define what we think the semantics of pg_read_barrier and pg_write_barrier actually are, so if you believe that a write barrier prevents reordering of reads relative to writes, you'd better propose some new text for that file. It certainly doesn't say that today. regards, tom lane -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers