As a last resort, {{ AbstractEntityPersister#isTransient }} calls {{ CacheHelper.fromSharedCache }} to determine if an entity is cached. If the return value is non-null, then the {{ AbstractEntityPersister#isTransient }} returns {{ false }} , and the return value is ignored.
When Infinispan is the cache provider, {{ CacheHelper.fromSharedCache }} calls [ {{ InvalidationCacheAccessDelegate#get }} |https://github.com/infinispan/infinispan/blob/9.4.x/hibernate/cache-commons/src/main/java/org/infinispan/hibernate/cache/commons/access/InvalidationCacheAccessDelegate.java#L56-L65]. If the entity is not already cached, {{ InvalidationCacheAccessDelegate#get }} adds a pending-put for the entity as a side-effect. The entry in the pending-put map uses a {{ SessionImpl }} as the map key.
If that entity really is transient, then the pending-put entry never gets cleared until it times out. Since the pending-put map contains {{ SessionImpl }} keys, those {{ SessionImpl }} objects cannot be garbage-collected until the entry times out.
If lots of data is in the process of being imported, then an {{ OutOfMemoryError }} could be thrown. IIUC, it is not recommended to use the cache when importing data. That is why I am calling this issue an "improvement" rather than a "bug". {{ [WFLY-13259|https://issues.redhat.com/browse/WFLY-13259] }} contains a test that reproduces this issue.
This improvement involves changing The original proposal was to change {{ AbstractEntityPersister#isTransient }} to call {{ CachedDomainDataAccess#get }} . Unfortunately , which calls that would not work consistently. For example, if an entity is deleted, and re-persisted while the deleted entity is still locked in the cache, {{ InvalidationCacheAccessDelegate CachedDomainDataAccess #get }} with a will return {{ null true }} , and {{ session AbstractEntityPersister#isTransient }} argument. Since will incorrectly return {{ session false }} is {{ null }} when re-persisting the new entity.
Instead , {{ InvalidationCacheAccessDelegate#get }} does an improvement would be to not add store a pending-put SharedSessionContractImplementor in a PendingPut at all.
There is already a way to get a UUID for the entity session by calling SharedSessionContractImplementor#getSessionIdentifier() . Unfortunately, the implementation in AbstractSharedSessionContract indicates that frequent "UUID generations will cause a significant amount of contention".
Sanne has suggested returning a "token" that is just a new Object. I've created a [branch|https://github.com/gbadner/hibernate-core/tree/HHH-13916_token] that does this.
Infinispan would need to be updated so that PendingPut#owner is set to SharedSessionContractImplementor#getSessionToken() (instead of the SharedSessionContractImplementor object). |
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