On Sat, 01 Dec 2012, Jeffrey Johnson wrote: > (aside) > Good: The behavior is symmetric when permuted. > > The documentation states that $1/$2 are the number of pkg instances > after the script is run. This isn't precise enough a definition > when there is an ACID transaction with a 2phase commit/discard > (as in rpm5). > > The definition of "installed" is the same (in rpm-5.4.10) as > Is the database transaction committed? > > The commit depends on whether scripts/triggers > (with the $1/$2 counts) succeed. In addition, > the status of all scripts run during install > is added to the header before being saved in an > rpmdb. > > This leads to a chicken <=> egg behavior, where the > header cannot be committed until the scripts are run > and the script arguments can't be computed until the > header is committed in the rpmdb. > > (aside) > There is the further issue of what degree of isolation > (and visibility) of concurrent transactions. The code > as written has full degree 2 isolation; if the header > is added to the rpmdb sooner, and pending/uncommitted > data is made visible, then the counts would be as you expect. > > Until saved (and the ACID transaction is committed), the > 0 being seen above is consistent with interpreting > installed == header registered/committed > (see the PSM_POST case in lib/psm.c, > where the rpmtxnCommit() call is done as part of PSM_RPMDB_ADD). > > I'm inclined atm to prefer the above actual behavior to "fudging" an > extra +1 for "legacy compatible" behavior; I'm sure we disagree here. > > Short answer: patch in an extra +1 (there will be two code paths in need > of patching, check for symmetry as above) if you wish "legacy compatible" > behavior.
Thank you for explanation and the patch, I tested it and it does bring back "legacy compatible" behavior. We do need that. -- Jan Rękorajski | PLD/Linux SysAdm | http://www.pld-linux.org/ baggins<at>mimuw.edu.pl baggins<at>pld-linux.org _______________________________________________ pld-devel-en mailing list pld-devel-en@lists.pld-linux.org http://lists.pld-linux.org/mailman/listinfo/pld-devel-en
