Re: How do I temporary retain self, under ARC?
Re: How do I temporary retain self, under ARC?
- Subject: Re: How do I temporary retain self, under ARC?
- From: Andy Lee <email@hidden>
- Date: Fri, 18 Jul 2014 10:07:17 -0400
You could even eliminate the (admittedly negligible) cost of setting keepAlive = nil by changing the if(keepAlive) to if(!keepAlive).
Along the lines of avoiding a message send, I wonder if this would work:
do {
// ...
} while (!self);
--Andy
> On Jul 18, 2014, at 9:41 AM, Gerd Knops <email@hidden> wrote:
>
> That's similar to what I have used. Initially it started out simply as
>
> id keepAlive=self;
> ...
> keepAlive=nil;
>
> but a few Xcode versions ago the static analyzer started complaining that it wasn't really doing anything. So that last line became
>
> if(keepAlive) { keepAlive=nil; }
>
> which shut up the analyzer. [keepAlive self]; like Andy suggests would probably work just as well, though probably a tad more expensive as a method call is involved.
>
> Gerd
>
>> On Jul 17, 2014, at 11:23 PM, Andy Lee <email@hidden> wrote:
>>
>>> On Jul 17, 2014, at 11:01 PM, Jens Alfke <email@hidden> wrote:
>>> Once I’ve identified such a bug, the fix is easy: put a [[self retain] autorelease] at the top of the method. Except now I’m using ARC, and I can’t find a simple way of doing it. I tried adding
>>> __unused id retainedSelf = self;
>>> but the optimizer recognizes that retainedSelf isn’t used and strips it out, making this a no-op. The only thing I’ve found that works is
>>> CFRetain((__bridge CFTypeRef)self);
>>> at the top of the method, and a corresponding CFRelease at the end, but this is pretty ugly and could cause leaks if the method returns early.
>>
>> How about
>>
>> id retainedSelf = self;
>>
>> at the beginning and
>>
>> [retainedSelf self];
>>
>> at the end?
>>
>> --Andy
>>
>>
>> _______________________________________________
>>
>> 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
>
_______________________________________________
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