Strange behavior when using child/parent NSManagedObjectContext

Question

I\'m developing an application where I need to both calculate things (multiple seconds operations) and write things (sync data with a server) on a background thread.

Bec

Answer 1

I had this problem and the solution was making sure all operations on the parent MOC are done with performBlock:, even the initial setup:

    parentManagedObjectContext = [[NSManagedObjectContext alloc] initWithConcurrencyType:NSPrivateQueueConcurrencyType];
    [parentManagedObjectContext performBlock:^{
        [parentManagedObjectContext setMergePolicy:NSMergeByPropertyObjectTrumpMergePolicy];
        [parentManagedObjectContext setPersistentStoreCoordinator:coordinator];
    }];

Once I did this, my child MOCs started picking up changes.