On 2017-06-06 17:14:59 -0400, Tom Lane wrote: > Andres Freund <and...@anarazel.de> writes: > > The function in $subject does: > > > ResetLatch(&MyProc->procLatch); > > rc = WaitLatchOrSocket(&MyProc->procLatch, > > WL_POSTMASTER_DEATH | WL_SOCKET_READABLE > > | > > WL_LATCH_SET, > > PQsocket(streamConn), > > 0, > > WAIT_EVENT_LIBPQWALRECEIVER); > > Yeah, this is certainly broken. > > > Afaict, the ResetLatch() really should just instead be in the if (rc & > > WL_LATCH_SET) block. > > And, to be specific, it should be before the CHECK_FOR_INTERRUPTS call, > since that is the useful work that we want to be sure occurs after > any latch-setting event.
Right. I found a couple more instance of similarly iffy, although not quite as broken, patterns in launcher.c. It's easy to get this wrong, but it's a lot easy if you do it differently everywhere you use a latch. It's not good if code in the same file, by the same author(s), has different ways of using latches. - Andres -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
