On 1-Dec-09, at 3:21 PM, Kyle Sluder wrote:
On Mon, Nov 30, 2009 at 1:33 PM, Ben Haller wrote:
This is interesting to me, since I am in fact using @public and ->
with
some ivars to allow faster use of one of my classes. (Yes, I've
confirmed
that this is significant in Sampler; it is, in fact, quite a large
percentage of the total time of my app, which has runtimes measured
in days,
so I do care :->). I understand the concept of the fragile base
class
problem and so forth; I just didn't realize Apple had done
something to fix
it that might affect the performance of my app. :->
Are you talking about an improvement over using accessor methods, or
over using non-fragile instance variables? Even though, as Greg
noted, it takes more work to do a non-fragile ivar access because of
the indirection, that is insignificant compared to the time that would
be spent in objc_msgSend. Especially if the ivars are used so often
that their symbols stick around in the cache.
Currently I'm using @public and accessing ivars directly (because,
as you say, objc_msgSend is slow). Apparently even direct ivar access
is slower than it used to be, due to non-fragile ivars glue emitted by
the compiler, as Greg pointed out. I'm looking for a way to win back
some or all of that speed. The previous suggestion of providing
access to a struct inside the class is a good idea, I'm going to
pursue that eventually.
Ben Haller
Stick Software
_______________________________________________
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:
http://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com
This email sent to arch...@mail-archive.com
