From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jeff King Subject: Re: Lockless Refs? Date: Sat, 29 Dec 2012 03:16:57 -0500 Message-ID: <20121229081657.GE15408@sigill.intra.peff.net> References: <20121221080449.GA21741@sigill.intra.peff.net> <50DAB447.8000101@alum.mit.edu> <201212271611.52203.mfick@codeaurora.org> <201212280750.14695.mfick@codeaurora.org> <7vhan6jdx3.fsf@alter.siamese.dyndns.org> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Cc: Martin Fick , Michael Haggerty , git@vger.kernel.org, Shawn Pearce To: Junio C Hamano X-From: git-owner@vger.kernel.org Sat Dec 29 09:17:23 2012 Return-path: Envelope-to: gcvg-git-2@plane.gmane.org Received: from vger.kernel.org ([209.132.180.67]) by plane.gmane.org with esmtp (Exim 4.69) (envelope-from ) id 1Torbc-00055o-Qv for gcvg-git-2@plane.gmane.org; Sat, 29 Dec 2012 09:17:21 +0100 Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752274Ab2L2IRC (ORCPT ); Sat, 29 Dec 2012 03:17:02 -0500 Received: from 75-15-5-89.uvs.iplsin.sbcglobal.net ([75.15.5.89]:38641 "EHLO peff.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752160Ab2L2IRB (ORCPT ); Sat, 29 Dec 2012 03:17:01 -0500 Received: (qmail 27769 invoked by uid 107); 29 Dec 2012 08:18:10 -0000 Received: from sigill.intra.peff.net (HELO sigill.intra.peff.net) (10.0.0.7) (smtp-auth username relayok, mechanism cram-md5) by peff.net (qpsmtpd/0.84) with ESMTPA; Sat, 29 Dec 2012 03:18:10 -0500 Received: by sigill.intra.peff.net (sSMTP sendmail emulation); Sat, 29 Dec 2012 03:16:57 -0500 Content-Disposition: inline In-Reply-To: <7vhan6jdx3.fsf@alter.siamese.dyndns.org> Sender: git-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: git@vger.kernel.org Archived-At: On Fri, Dec 28, 2012 at 09:15:52AM -0800, Junio C Hamano wrote: > Martin Fick writes: > > > Hmm, actually I believe that with a small modification to the > > semantics described here it would be possible to make multi > > repo/branch commits work.... > > > > Shawn talked about adding multi repo/branch transaction > > semantics to jgit, this might be something that git wants to > > support also at some point? > > Shawn may have talked about it and you may have listened to it, but > others wouldn't have any idea what kind of "multi repo/branch > transaction" you are talking about. Is it about "I want to push > this ref to that repo and push this other ref to that other repo", > in what situation will it be used/useful, what are the failure > modes, what are failure tolerances by the expected use cases, ...? > > Care to explain? I cannot speak for Martin, but I am assuming the point is to atomically update 2 (or more) refs on the same repo. That is, if I have a branch "refs/heads/foo" and a ref pointing to meta-information (say, notes about commits in foo, in "refs/notes/meta/foo"), I would want to "git push" them, and only update them if _both_ will succeed, and otherwise fail and update nothing. I think Shawn mentioned this at the last GitTogether as a stumbling block for pushing more of Gerrit's meta-information as refs over the git protocol. But I might be mis-remembering. -Peff