On 08/01/2013 10:41 AM, Scott Marlow wrote: >>> - The shared non-thread-safe content finding looks like it spots a >>> symptom of a real bug: in the method 'getNamedEntityManagerFactory', a >>> hashmap is extracted from a concurrent hash map and read from. >>> Concurrently, there is the possibility that items are removed from the >>> hash maps. There is no common lock guarding these accesses. This may >>> cause, at worst, infinite loops, if the hashmap is accessed in an >>> inconsistent state. >> I actually have no idea why it keeps a Set for each name. Seems to me >> the code ultimately throws an exception anyway if more than one was >> registered under that name, so why not just store >> name->EntityManagerFactory? Scott? > > We could of thrown an exception if more than one was registered under > that name but Emmanuel had a good concern about how that would break > Hibernate applications that are clustered in some platforms (as well as > applications that serialize/deserialize the EntityManagerFactory). > > Instead of throwing an exception when multiple EMFs are added under the > same name, we log a warning and track the multiple EMFs registered under > a particular name. > > However, we do throw an exception only when the attempt to deserialize > the EMF by name but there are more than one EMFs registered (see > EntityManagerFactoryRegistry.getNamedEntityManagerFactory(String name)). > > The distinction is that applications might create multiple EMFs with the > same name and we allow that but will throw an error, for the smaller set > of apps that actually try to deserialize the EMF by name. > > It does look like > EntityManagerFactoryRegistry.getNamedEntityManagerFactory(String name), > is reading an unprotected Set that could be updated concurrently from a > different thread. > > Any other feedback about this thread safety bug before I create a HHH jira?
HHH-8406 is for fixing the thread safety issue. > > Scott > _______________________________________________ > hibernate-dev mailing list > hibernate-dev@lists.jboss.org > https://lists.jboss.org/mailman/listinfo/hibernate-dev > _______________________________________________ hibernate-dev mailing list hibernate-dev@lists.jboss.org https://lists.jboss.org/mailman/listinfo/hibernate-dev
