On Nov 21, 2010, at 11:47, vincent habchi wrote: > briefly speaking, I have a Core Data Entity bearing a to-many relationship > (therefore an NSSet * iVar).
It's not an ivar, it's a property. > A dialog on the main thread can modify this set, You can't modify a NSSet. I suspect you mean "modify this relationship", but the ambiguity leads me to wonder if you're trying to do something funky here. Not that it's relevant to your actual question ... > while it may be simultaneously enumerated on a background GCD thread. I have > therefore used the managed object context provided mutex to protect the > respective snippets. > > I am improving the background thread, replacing the enumeration by a fetch > operation. Do I still need the lock, or is it provided internally by the Core > Data framework? Look at: http://developer.apple.com/library/mac/#documentation/Cocoa/Conceptual/CoreData/Articles/cdMultiThreading.html under the heading "General Guidelines". If I understand your scenario correctly, you've been using approach #3, the one labeled "This approach is strongly discouraged". Use approach #1 (except in the unlikely case that performance is an issue without full concurrency, in which case use approach #2). _______________________________________________ Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to arch...@mail-archive.com