On Sep 12, 2016, at 10:16 , Jens Alfke <j...@mooseyard.com> wrote: > > The question in my mind is whether the array struct ever gets copied in this > code — it’s not explicitly passed as a parameter, just closed over. I don’t > think I’ve read any docs that describe explicitly what the behavior is, maybe > because it only becomes significant when you introduce threads?
The array is going to get copied at least once, because it’s a local variable captured by a block. That means it needs to be copied to the heap. > This situation also begs the question of what kind of lower-level data > structure one can use in Swift when Array is too high-level. In Obj-C one can > drop down to C arrays, for example. My understanding is that pure Swift arrays (that is, *not* bridged NSArrays) are stored as efficiently as C arrays. However, in this particular example, the array, a mutable structure, is modified unsafely from multiple threads. That may or may not be the cause of the crash, but it’s certainly a bug that should be fixed first. _______________________________________________ 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
