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]. [1] - https://www.postgresql.org/message-id/CAA4eK1%2BQ_DdJ28qXYSHZiBKNf2MY1QFrv5XAOAw4ZXHw4TPMxA%40mail.gmail.com -- With Regards, Amit Kapila. EnterpriseDB: http://www.enterprisedb.com -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
