On Fri, Mar 18, 2016 at 1:53 PM, Andres Freund <and...@anarazel.de> wrote: > On 2016-03-18 05:56:41 -0400, Robert Haas wrote: >> >> 0 at the top of the loop and skip it forthwith if so. >> > >> > You mean in WaitEventSetWait()? There's >> > else if (rc == 0) >> > { >> > break; >> > } >> > which is the timeout case. There should never be any other case of >> > returning 0 elements? >> >> No, I meant if (cur_event->events == 0) continue; > > I'm not following. Why would there be an event without an empty event > mask? Ok, you can disable all notifications for a socket using > ModifyWaitEvent(), but that's not particularly common, right? At least > for epoll, it'd not play a role anyway, since epoll_wait() will actually > return pointers to the elements we're waiting on; for windows we get the > offset in ->handles. I guess we could do so in the select/poll case, > but adding another if for something infrequent doesn't strike me as a > great benefit.
No, I mean it should be quite common for a particular fd to have no events reported. If we're polling on 100 fds and 1 of them is active and the other 99 are just sitting there, we want to skip over the other 99 as quickly as possible. -- 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