[Christian Heimes] >>> From my point of view I can't see a reason why the ZODB forbids a >>> second rolback to the savepoint.
[Jim Fulton] >> I agree. This should be changed. [Tim Peters] > Sounds good to me -- it looks easy, so I'll do it <wink>. Something subtler than I've been able to figure out yet is going wrong, so I made a tim-savepoint branch. All the tests pass, but ... After my first round of changes, subtxn abort (transaction.abort(1)) tests failed. Turned out the code implementing abort(1) relied on that savepoint.rollback() marked `savepoint` as invalid, and that was easily repaired (changed abort(1) to explicitly mark the subtxn savepoint as invalid). But after thinking about it, I couldn't understand _why_ that repair was needed (except perhaps as an optimization), and that spawned this failing code, which doesn't use subtxns: """ import ZODB from ZODB.FileStorage import FileStorage import transaction from BTrees.IIBTree import IIBTree st = FileStorage("blah.fs") db = ZODB.DB(st) cn = db.open() rt = cn.root() tree = rt['tree'] = IIBTree() tree = 1 transaction.commit() tree = 2 sp2 = transaction.savepoint() tree = 3 sp3 = transaction.savepoint() tree = 4 assert tree == 4 sp3.rollback() assert tree == 3 if 1: # turns out this is irrelevant; "if 0" fails the same way tree = 4 assert tree == 4 sp3.rollback() assert tree == 3, (tree, 3) """ The second time sp3.rollback() is done, it seems to revert the state all the way back to the first commit: tree is back to 1 again. The same kind of thing happened under abort(1) if the subtxn savepoint wasn't explicitly marked as invalid. Stepping thru it under pdb didn't reveal the cause, which means I must have stepped over the important parts ... I'll try again later. _______________________________________________ For more information about ZODB, see the ZODB Wiki: http://www.zope.org/Wikis/ZODB/ ZODB-Dev mailing list - ZODB-Dev@zope.org http://mail.zope.org/mailman/listinfo/zodb-dev