Persistence context propagation occurs for container-managed entity managers

In a transaction-scoped container managed entity manager (common case in a Java EE environment), the JTA transaction propagation is the same as the persistence context resource propagation. In other words, container-managed transaction-scoped entity managers retrieved within a given JTA transaction all share the same persistence context. In Hibernate terms, this means all managers share the same session.

Context Propagation

Persistence context are never shared between different JTA transactions or between entity manager that do not came from the same entity manager factory. There are some noteworthy exceptions for context propagation when using extended persistence contexts:

• If a stateless session bean, message-driven bean, or stateful session bean with a transaction-scoped persistence context calls a stateful session bean with an extended persistence context in the same JTA transaction, an IllegalStateException is thrown.
• If a stateful session bean with an extended persistence context calls as stateless session bean or a stateful session bean with a transaction-scoped persistence context in the same JTA transaction, the persistence context is propagated.
• If a stateful session bean with an extended persistence context calls a stateless or stateful session bean in a different JTA transaction context, the persistence context is not propagated.
• If a stateful session bean with an extended persistence context instantiates another stateful session bean with an extended persistence context, the extended persistence context is inherited by the second stateful session bean. If the second stateful session bean is called with a different transaction context than the first, an IllegalStateException is thrown.
• If a stateful session bean with an extended persistence context calls a stateful session bean with a different extended persistence context in the same transaction, an IllegalStateException is thrown.

Hibernate does not throw IllegalStateException if you violate the above rules, but it has side effects.