Hi Jeff,

>> Slim3 locks an entity group when getting, putting and deleting entities
>> so that nobody updates the entity group. So it never happens
>> that the first two entity group transactions commit and the third fails.
>
> What do you do when there is a lock conflict?
>
> ThreadA locks Resource1
> ThreadB locks Resource2
> ThreadA tries to lock Resource2... what happens?

When ThreadA tries to lock Resource2, ThreadA will encounter
a ConcurrentModificationException, and the other locks that ThreadA has
(the lock for Resource1) will be released automatically.

> What happens when a datastore error prevents
> the lock from being deleted?
>
If the transaction is not committed for same reasons,
the locks will be released 30 seconds later.

Yasuo Higa

-- 
You received this message because you are subscribed to the Google Groups 
"Google App Engine for Java" group.
To post to this group, send email to [email protected].
To unsubscribe from this group, send email to 
[email protected].
For more options, visit this group at 
http://groups.google.com/group/google-appengine-java?hl=en.

Reply via email to