Does CoreData ensure safe operation in a multithreaded environment?

CoreData is not fully thread-safe. NSManagedObjectContext instances cannot be used simultaneously from different threads.

To work safely in a multithreaded environment, you need to:

• Create a separate NSManagedObjectContext for each thread.
• Use a context type of NSPrivateQueueConcurrencyType or NSMainQueueConcurrencyType.
• Perform operations with the context inside its perform or performAndWait blocks to ensure sequential access.

Thus, CoreData supports multithreading through proper use of contexts and queues, but developers must follow these rules to avoid thread safety issues.