• Open Menu Close Menu
  • Apple
  • Shopping Bag
  • Apple
  • Mac
  • iPad
  • iPhone
  • Watch
  • TV
  • Music
  • Support
  • Search apple.com
  • Shopping Bag

Lists

Open Menu Close Menu
  • Terms and Conditions
  • Lists hosted on this site
  • Email the Postmaster
  • Tips for posting to public mailing lists
Re: NSOperation -dealloc not called
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: NSOperation -dealloc not called


  • Subject: Re: NSOperation -dealloc not called
  • From: Andreas Grosam <email@hidden>
  • Date: Thu, 30 Sep 2010 18:18:28 +0200

Setting the block to nil within the block itself actually did the trick.

Thank you very much for the quick reply and the correct solution! :)

Andreas



On Sep 30, 2010, at 5:21 PM, Dave DeLong wrote:

> By referencing instance variables within the block, you're causing the block to retain self, and since self retains (copy'd) the block, you've got a retain cycle.
>
> The easiest way to fix this is to break the retain cycle yourself.  Doing "[self setCompletionBlock:nil];" at the end of the block should be adequate.
>
> Dave
>
> On Sep 30, 2010, at 9:17 AM, Andreas Grosam wrote:
>
>> I've subclassed a NSOperation and declared a completion block in the initializer as follows:
>>
>> - (id) initWithParameter:(id)parameter
>> {
>>  self = [super init];
>>  if (self != nil) {
>>      [self setCompletionBlock:^{
>> 	    NSLog(@"operation completed");
>>          [someIvar release], someIvar = nil;
>>      }];
>>
>>      // ... initialize ivars
>>  }
>>  return self;
>> }
>>
>>
>> The problem is now, once a completion block has been defined and set as shown above, the NSOperation instance will never be dealloced. I noticed, when -setCompletionBlock: returns, the retain count of the NSOperation instance has been incremented by one.
>>
>> When there is no completion block set, the NSOperation object will be deallocated as expected some time later when the operation finished.
>>
>> The -initWithParameter: method is invoked on the main thread.
>>
>> The code of the completion block is trivial: It logs to the console and simply releases certain ivars. So, there should no autoreleased object (namely the operation object itself) left in some unknown execution context possibly without a pool and hence leaking.
>>
>>
>> As a side note: according the docs, the exact execution context for the completion block is undefined. So, I think this means, we should better use synchronization primitives when accessing ivars since the dealloc method might still executing, right?
>>
>>
>> This is running on iOS.
>>
>>
>> Any hints?
>>
>>
>>
>> Thanks in advance
>> Andreas
>> _______________________________________________

_______________________________________________

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

References: 
 >NSOperation -dealloc not called (From: Andreas Grosam <email@hidden>)
 >Re: NSOperation -dealloc not called (From: Dave DeLong <email@hidden>)

  • Prev by Date: Re: NSOperation -dealloc not called
  • Next by Date: Re: Acquiring an NSConnection otherwise than by registered name?
  • Previous by thread: Re: NSOperation -dealloc not called
  • Next by thread: Changing classes
  • Index(es):
    • Date
    • Thread