On Sun 28 Jun 2020 at 13:19 -0300, David Bremner wrote: > Floris Bruynooghe <f...@devork.be> writes: > >> Hi, >> >> I started writing some test cases to define better what you can do with >> a closed database and make sure that the python bindings do not behave >> unexpectedly here too. >> >> One of the first things I tried ends up with xapian calling >> exit_group(2) directly, terminating the process. So I'm wondering if >> I'm approaching this entirely the wrong way. My understanding is that >> we should generally be allowed to use anything after the database has >> been closed, as long as nothing has been destroyed. >> >> Below is a minimal reproducible example of what I'm testing so far. I >> must admit I'm generally lazy here and usually just test with notmuch >> that is currently in Debian testing. > > Funny that you should mention lazy, that's basically what the problem is > here ;). notmuch_message_get_message_id is lazily trying to read the > information from the database. This is a bit surprising here because of > the query, but that's not really visible once the message object is > created. > > In principle it could be documented what parts of the API can trigger > access to the database, but I'm not sure about the benefit of the extra > complexity. It might be safer to assume that only access to already > fetched information is safe. In particular if you move > > messageid = notmuch_message_get_message_id(msg); > > before you close the database, then printing it out afterwards works. I > didn't run it valgrind to make sure, but afaik, that should be perfectly > legal.
Ok, I forgot the "expected behaviour" part of the bug report ;) I think that this doesn't work is fine and I'm not surprised by and your description of fetching it first is very reasonable. However I was expecting NOTMUCH_STATUS_XAPIAN_EXEPTION instead of bluntly getting terminated. This is what the notmuch_database_close() docs say after all. I had a little look and this seems to be caused by the message->doc.termlist_begin() call in _notmuch_message_ensure_metadata(), I didn't have xapian debug symbols and am not familiar with xapian to quickly have an idea of whether this case can be improved or not. (-dbg debian packages for notmuch and xapian would be very handy ;)) But part of my question is, *should* this be improved? Am I interpreting notmuch's intended API correctly? > The original motivation (see 7864350c938944276c1a378539da7670c211b9b5) > to allow long running processes to release the lock on the > database. This is not a pattern we use in the CLI, so it's not as well > tested as it could be. In particular the work to export > notmuch_database_reopen (tests, documentation) has not happened yet. > > d _______________________________________________ notmuch mailing list email@example.com https://notmuchmail.org/mailman/listinfo/notmuch