On Mar 6, 2012, at 1:51 PM, Jan E. Schotsman wrote: > Hello, > > I have an array of progress values (number objects) for subprojects, from > which I calculate the overall progress . > The array is an atomic property of the project class. > > Is it safe to access this array from multiple threads, using methods like > objectAtIndex and replaceObjectAtIndex?
(Resending since my original reply, written yesterday, still hasn’t posted; apologies if this ends up showing up twice on the list.) It’s not; however, if you implement the KVO indexed accessors for to-many properties, described here: https://developer.apple.com/library/mac/#documentation/Cocoa/Conceptual/KeyValueCoding/Articles/AccessorConventions.html#//apple_ref/doc/uid/20002174-178830-BAJEDEFB and guard each accessor with a mutex, spinlock, dispatch_sync, or something similar, you should then be able to use -mutableArrayValueForKey: to return an NSMutableArray proxy that you can use like an ordinary NSMutableArray, but which will call your now-atomic indexed accessors to get at the contents of the array. Just make sure all accessors are properly thread-safe and that none of them return the actual ivar backing the property, and you should be fine. Charles _______________________________________________ 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: https://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to arch...@mail-archive.com
