Kill a task after 10 seconds in Core Data

Question

I have a function that sometimes takes too long to run. I want to attempt to run it for 10 seconds, and then just kill it if it's not done. How do I do this in Objective C on the iPhone?

Creating the persistent store coordinator is failing for some users who have a lot of data in their database, because the object model merging takes too long. We've moved that data storage out of the database, but I want to kill the model merging if it takes more than a set time limit, and delete the database file so that the users can continue to use the app.

NSPersistentStoreCoordinator* psc = [[[NSPersistentStoreCoordinator alloc] 
                                        initWithManagedObjectModel: [self managedObjectModelForDatabase:dbName]] autorelease];

Answer 1

You can use -performSelector:withObject:afterDelay: to schedule a message to be sent in the future.

Answer 2

Can you perform your merge in a different thread (don't forget to make a different NSManagedObjectContext for this background thread) and then just have the main thread display a progress message while waiting for an asynchronous finish event from the background migration thread?

I do this in one of my apps with tons of data to avoid the iPhone killing my app during the merge process.