From: Loren Stafford [mailto:lstaffor@dynalogic.com]
My product's initialize(context) procedure creates a ZCatalog if that catalog doesn't already exist. I've defined an additional method armed_event() for the Catalog object. Later, the same product _init_.py module calls armed_event() (OK -- it's called from a thread spawned by initialize(context)).
Do you create a new DB connection?
When the catalog is created in the same product load process, the call to the catalog method armed_event() yields this output from pdb:
C:/Zope214\lib\python\Products\ZScheduler\ZSchedule.py(47)arme d_event()
...which is what I would expect.
However, when the catalog already exists (from a previous product load), the call to the catalog method yields this output:
C:\Zope214\lib\python\ZODB\Connection.py(386)setstate()
I didn't write any setstate methods, so I presume this is extension class or persistence voodoo. If so, the fact that pdb doesn't show how it got to setstate must be due to the fact that that logic is written in C. Somewhere, somehow, (perhaps via an inherited __setstate__ method) Zope has figured out that the catalog object has to be loaded from the ZOSB before it can proceed, and calls on Connection.py\setstate to help do so. Right, so far?
Indeed, via the Persistence class, the ZODB is asked to retrieve the object. How do you access the Catalog? You should obtain a new Root object for your new thread, and traverse to the Catalog via that reference. When you use the ZServer Monitor, you have to do the same thing: import Zope app=Zope.app() You then have your own connection to the database. When you are done with it (basically every time you go to sleep in the thread), you close it again: app._p_jar.close() del app This way you keep conflicts down, performance up.
OK, tracing along in setstate(), we get to this statement and exception:
C:\Zope214\lib\python\ZODB\Connection.py(391)setstate() -> p, serial = self._storage.load(oid, self._version) (Pdb) s AttributeError: "'None' objec...ribute 'load'" C:\Zope214\lib\python\ZODB\Connection.py(391)setstate() -> p, serial = self._storage.load(oid, self._version) (Pdb)
OOps! This connection's storage object has no load method. How can that happen? Because pdb isn't showing how it got here, it's hard to see what the cause is. Can someone who's been here before help me out?
Was the Catalog object not defined properly or not initialized properly? If not, how is the Catalog storage object supposed to be initialized?
The storage is not defined. Probably because the Conection has been closed in the meantime, which is what happens as soon as initialisation of products is done. See lib/python/Zope/__init__.py HTH -- Martijn Pieters, Software Engineer | Digital Creations http://www.digicool.com | Creators of Zope http://www.zope.org | mailto:mj@digicool.com ICQ: 4532236 | PGP: http://wwwkeys.nl.pgp.net:11371/pks/lookup?op=get&search=0xA8A32149 -------------------------------------------