Threading - Core Data - page 94

Persistent Store
Coordinator

Private Queue

Main Queue

Parent Context

Changes pushed up

A Context

Changes pushed down

Child Context

Figure 17—Private queue for asynchronous saves

Baseline/PPRecipes/PPRAppDelegateAlt1.m
- ( void )saveContext:(BOOL)wait
{

NSManagedObjectContext *moc = [self managedObjectContext];
NSManagedObjectContext *private = [self privateContext];

if (!moc) return ;
if ([moc hasChanges]) {
[moc performBlockAndWait:^{
NSError *error = nil;
ZAssert([moc save:&error], @ "Error saving MOC: %@\n%@" ,
[error localizedDescription], [error userInfo]);

}];

}