On 2012-01-26, at 6:09 PM, Jeff Kelley wrote: > Without ARC, you would use __block to prevent the block from retaining the > object and causing the retain cycle. With ARC, however, the object is > retained when you put it into the variable, so to avoid a retain cycle, you > have to declare it like so: > > __unsafe_unretained __block MyViewController *myController = … > > It looks awful, yes, but without the first piece we were having extreme > memory leaks.
Maybe I'm reading this wrong, but I think this might be a bit too unsafe. If you declare something as __unsafe_unretained, ARC won't try to track the variable through its lifetime, so if for some reason that variable is deallocated and then your block gets called, your app will crash. The OP's code feels a bit safer to me: it retains the variable strongly, then Nils it at the end of the block to force a release. There's no retain cycle or memory leak, and the __block variable is guaranteed to stick around until your block is done with it. —Mt. _______________________________________________ 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
