Use Automatic Reference Counting

[jan-christiansen]

What do you think about moving to ARC? More precisely, how about removing reference counting in single files and transfer the project step by step. Does anybody have any experience with a mixed ARC/non-ARC project? Are there any arguments against using ARC?

[trasch]

I want to remove iOS 4 compatibility as soon as iOS 6 is public, this will then also include switching the project to ARC. This means late summer, I guess.

[jan-christiansen]

As far as I know you don't have to abandon iOS 4 support if you use assign instead of weak references in ARC but I might be mistaken here. However, as you plan to drop iOS 4 compatibility anyway it is probably not worth the trouble.

[MapaX]

Almost 30% of my application users are still using iOs 4.x, so I cannot drop yet the iOs 4.x
But you can use ARC in 4.0 so its not a problem.

[teacup775]

I have pulled MapBox's SDK and converted to ARC in 5 minutes. It took only a few lines to comment out for the use of AutoRelease pool in the RMMapTiledLayerView and changes handled in a semi automated way to change retain to "strong" etc.

When you get to it, it won't be all that bad.

[incanus]

Have you looked over the subtleties of the map view retaining the tiled layers due to the odd cleanup behavior of CATiledLayer when on a memory-constrained device? It gets tricky.

On Oct 5, 2012, at 8:19 PM, teacup775 [email protected] wrote:

I have pulled MapBox's SDK and converted to ARC in 5 minutes. It took only a few lines to comment out for the use of AutoRelease pool in the RMMapTiledLayerView and changes handled in a semi automated way to change retain to "strong" etc.

When you get to it, it won't be all that bad.

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Reply to this email directly or view it on GitHub.

[teacup775]

Can you clarify? In particular, what is the nature of the retaining the layers and what is odd nature of CATileLayer cleanup? I tried googling around and didn't find any specifics.

I've run profiling for leaks, smashed the simulate memory warnings on a simulator run and it remains clean. Running on hardware (a 3gs) doesn't show any leaks -- but I don't know any tricks to force a memory warning, unless playing InfinityBlade will do it. :)

I've noticed several bits of async invocation in the code, in particular the before/after move and zoom code areas, and also spawning an async tile download in the tile code. Not having large experience with CATileLayer, which seems to be an underdocumented class from Googled comments,I can see it's a bit of a pleasure/pain class in the framework.

On principal I can understand why a rendering class that invokes work in multiple threads could cause some headaches. Still, the point of ARC conversion is to remove hand coded retain/release and have the compiler manage it automagically. If the existing code doesn't have any bugs with regard to handling the references, introducing ARC probably won't add them (crossing fingers).

I
On Oct 5, 2012, at 9:01 PM, Justin R. Miller [email protected] wrote:

Have you looked over the subtleties of the map view retaining the tiled layers due to the odd cleanup behavior of CATiledLayer when on a memory-constrained device? It gets tricky.

On Oct 5, 2012, at 8:19 PM, teacup775 [email protected] wrote:

I have pulled MapBox's SDK and converted to ARC in 5 minutes. It took only a few lines to comment out for the use of AutoRelease pool in the RMMapTiledLayerView and changes handled in a semi automated way to change retain to "strong" etc.

When you get to it, it won't be all that bad.

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Reply to this email directly or view it on GitHub.

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Reply to this email directly or view it on GitHub.