From my reading of the code, you will want explicitly add Models from a TIM dataset to the OntDocumentManager instance. In other words, don't use getOntology with having added the Model yourself, or the OntDocumentManager instance will create a Model outside the TIM dataset to give you. But I wouldn't pretend to be very familiar with the ontology side of things.
--- A. Soroka The University of Virginia Library > On Jul 17, 2016, at 5:22 AM, Andy Seaborne <a...@apache.org> wrote: > > Better: transactions (3.1.0) > > http://jena.staging.apache.org/documentation/txn/transactions.html > > We now have a fully ACID transactional in-memory graph (TIM) as well as TDB. > > The "Txn" highlevel API is not in the released codebase. > > http://jena.staging.apache.org/documentation/txn/txn.html > > Planning now for transactions should make things a lot easier later. > > Andy > > On 16/07/16 16:03, Martynas Jusevičius wrote: >> On a second thought, since our code is only reading from the models, it is >> probably easier and safer just to clone the shared model into a per-request >> copy, and keep the code as it is. > > If the shared model is only ever read, you can share it. > > (getOntology isn't a read operation.) > >> >> Is the following code the fastest way to do it? Is add() expensive? >> >> >> OntModel ontModel = >> OntDocumentManager.getInstance().getOntology(ontologyURI, ontModelSpec); >> OntModel clonedModel = ModelFactory.createOntologyModel(ontModelSpec); >> clonedModel.add(ontModel); >> >> >> On Sat, Jul 16, 2016 at 3:47 PM, Martynas Jusevičius <marty...@graphity.org> >> wrote: >>> Hey, >>> >>> in our webapp, all objects are created per-request, except ontologies >>> stored in a shared OntDocumentManager, that are accessed like this: >>> >>> OntDocumentManager.getInstance().getOntology(ontologyURI, ontModelSpec); >>> >>> This has caused some ConcurrentModificationExceptions. >>> I have read the >>> https://jena.apache.org/documentation/notes/concurrency-howto.html >>> document, and wanted to check if I get this right. >>> >>> Basically, every operation and iterator on a shared OntModel has to be >>> in a critical section? Even if it's indirect and called on an OntClass >>> from the OntModel: >>> >>> OntModel ontModel = >>> OntDocumentManager.getInstance().getOntology(ontologyURI, >>> ontModelSpec); >>> ontModel.enterCriticalSection(Lock.READ); >>> try >>> { >>> OntClass ontClass = ontModel.getOntClass("http://some/class";); >>> NodeIterator it = ontClass.listPropertyValues(GC.supportedMode); >>> try >>> { >>> while (it.next) >>> ... >>> } >>> finally >>> { >>> it.close(); >>> } >>> } >>> finally >>> { >>> model.leaveCriticalSection() ; >>> } >>> >>> Is that correct? >>> >>> Martynas >> >
