On Tuesday, May 29, 2012 08:42:43 PM Andres Freund wrote: > Hi, > > On Monday, May 28, 2012 07:11:53 PM Tom Lane wrote: > > Andres Freund <and...@2ndquadrant.com> writes: > > > Does anybody have a better idea than to either call WalSndWakeup() at > > > essentially the wrong places or calling it inside a critical section? > > > > > > Tom, what danger do you see from calling it in a critical section? > > > > My concern was basically that it might throw an error. Looking at the > > current implementation of SetLatch, it seems that's not possible, but > > I wonder whether we want to lock ourselves into that assumption. > > The assumption is already made at several other places I think. > XLogSetAsyncXactLSN does a SetLatch and is called from critical sections; > several signal handlers call it without any attention to the context. > > Requiring it to be called outside would make its usage considerably less > convenient and I don't really see what could change that would require to > throw non-panic errors. > > > Still, if the alternatives are worse, maybe that's the best answer. > > If we do that, though, let's add comments to WalSndWakeup and SetLatch > > mentioning that they mustn't throw error. > > Patch attached. I would like to invite some more review (+commit...) here ;). Imo this is an annoying bug which should be fixed before next point release or beta/rc comes out...
Andres -- Andres Freund http://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Training & Services -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers