Asynchronous fetch with an NSFetchedResultsController

asyncFetchFRC.m

[[[self fetchedResultsController] managedObjectContext] performBlock:^{
    NSError *fetchError = nil;
    
    if (![self fetchedResultsController] performFetch:&fetchError]){
        /// handle the error. Don't just log it.
    } else {
        // Update the view from the main queue.
        [[NSOperationQueue mainQueue] addOperationWithBlock:^{
            [tableView reloadData];
        }];
    }
}];