On Sat, Sep 17, 2016 at 2:40 AM, Amit Kapila <amit.kapil...@gmail.com> wrote: > On Fri, Sep 16, 2016 at 11:54 PM, Robert Haas <robertmh...@gmail.com> wrote: >> >> + /* >> + * We need a write barrier to make sure the update of >> + * parallel_terminate_count is done before the store to in_use >> + */ >> >> Does the order actually matter here? >> > > I think so. If slot->in_use is reordered before the check of > is_parallel_worker, then it is possible that concurrent registration > of worker can mark the is_parallel_worker as false before we check the > flag here. See explanation in previous e-mail [1].
Tricky. I believe you're right. -- Robert Haas EnterpriseDB: http://www.enterprisedb.com The Enterprise PostgreSQL Company -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
