Hi Craig, On 2017-07-31 14:08:58 +0800, Craig Ringer wrote: > Hi all > > I've been looking into the wait event set interface added in 9.6 with an > eye to using it in an extension that maintains a set of non-blocking libpq > connections to other PostgreSQL instances. > > In the process I've been surprised to find that there does not appear to be > any interface to remove a socket once added to the wait event set, or > replace it with a new socket. > > ModifyWaitEvent(...) doesn't take a pgsocket. There doesn't seem to be a > way to remove an event from the set either.
Yea, and what's even more annoying, you can't "disable" waiting for readyness events on a socket, we've an assert that we're waiting for something. > Discussion in > https://www.postgresql.org/message-id/flat/20160114143931.GG10941%40awork2.anarazel.de > talks about a proposed SetSocketToWaitOn(...)/AddSocketToWaitSet and > RemoveSocketFromWaitSet etc. But it looks like it petered out and went > nowhere, apparently mainly due to not being needed by any current core > users. I think it just needs somebody to push this forward. > I'd like to add such interfaces at some point, but for now can work around > it by destroying and re-creating the wait event set when the fd-set > changes. So I'm posting mostly to confirm that it's not supposed to work, > and ask if anyone thinks I should submit a comment patch to latch.c > documenting it. It doesn't work, right. I'm not sure I see the point of adding comments explaining that a nonexistant interface doesn't exist? Greetings, Andres Freund -- Sent via pgsql-hackers mailing list (email@example.com) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers