Re: Zeroing out instance variables
Re: Zeroing out instance variables
- Subject: Re: Zeroing out instance variables
- From: Uli Kusterer <email@hidden>
- Date: Sat, 17 Apr 2010 16:53:25 +0200
On 17.04.10 16:47, Ken Thomases wrote:
On Apr 17, 2010, at 9:37 AM, Paul Sanders wrote:
That is, retain counts are stored outside of the instance.
In that case there is a danger that a pointer to whatever is referenced would be transferred to the copy of the object, which is not what you want.
No, you misunderstand. There is (in the scheme I'm vaguely recalling) _nothing_ inside the instances which holds or points to something which holds the retain count.
There is another data structure entirely which maps from object addresses to a retain count.
The question is: Is it documented as a fact you can rely on that this is
the case? If not, I at least wouldn't rely on it for shipping code. Even
if it was for an "at home" project I'd think about it long and hard.
Tracking down subtle memory bugs caused by Apple deciding to move the
reference count into an NSObject instance variable after all doesn't
sound like a fun occupation.
Cheers,
-- Uli
http://www.zathras.de
_______________________________________________
Cocoa-dev mailing list (email@hidden)
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:
This email sent to email@hidden