On Jul 26, 2006, at 12:52 PM, Chris McDonough wrote:
FWIW I believe by default at least, open ZODB connections are tied
to the thread which did the opening (they are returned to a pool
when closed and reused, possibly in another thread). And indeed
each connection does have a cache; caching is one of the primary
responsibilities of a connection object.
See the documentation in ZODB/interfaces.py for "IConnection".
I *think* what is happening here is that you are committing the
transaction devoted to the current connection/thread, and trying to
close a connection that has pending changes from another thread.
So when you do transaction.abort(), it's aborting the transaction
involving the current thread, not the one associated with the other
connection.
That said, I'm not entirely sure what to tell you to do here; there
used to be an API named "setLocalTransaction" or somesuch that
allowed you to control the one-thread-per-connection policy wrt to
a transaction minimally, IIRC. This API has disappeared, probably
replaced with something more flexible, but I'm not sure what that
is. I suspect it may have something to do with the
transaction_manager parameter to DB.open() however.
Open the database with an explicit transaction_manager if you want to
manage these yourself, instead of using the thread default.
If you have a connection, get the transaction_manager off of the
connection. Can't find it in the interface, unfortunately, but I
believe it to be reliable.
All that said, Chris S, it sounds like you might be attacking a
solved problem--and *might* be adding some serious unnecessary
complexity. Maybe you ought to take a step back and see if anyone
has a general approach to what you want? For instance, you said
The reason why I'm doing this is because I'm trying to update the
classes of persistent objects loaded into memory.
Want to elaborate on this a bit? It sounds like stuff other folks
have done, but you might want to give more detail.
Gary
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