[Zope] ConflictError with *one* ZEO client?

[Berthold Stöger]

On Thursday 29 June 2006 18:56, Dieter Maurer wrote:
> Good application design would make the conflict probability so low
> that it is very unlikely that a "ConflictError" propagates to
> the user.

For more complicated applications  this is only possible with locking. Does 
Zope provide locking primitives?

Or, ideally, something like asynchronous message passing? I would love to be 
able to start a transaction and, if it finishes in less than x seconds, tell 
the user the result or, if it hasn't finshed by then, that the transaction is 
being processed, please come back later.

Thanks...