On Jan 26, 2012, at 1:51 PM, Jan E. Schotsman wrote: > Supposedly this avoids a retain cycle. But where is the cycle? At least two > objects are needed for a cycle. What is the second one?
The block. When a block is copied (which it has to be, in order to be called later after the calling function has returned) it becomes a bona fide object. And this object retains objects in variables that are referred to in the block's code; myController in this case. And since myController presumably has a reference to the block too (so that it can call it), you have a cycle. The extra line to set "myController = nil" at the end breaks the cycle. —Jens _______________________________________________ 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
