Databases
StackOverflow2013
Postsdbo
PO
 

Note that there are some explanatory texts on larger screens.

plurals
  1. PO
    primarykey
    data
    text
    <p>First:</p> <p>you have a possible and visible leak, but I'm not sure if it is the same leak you have found in instruments:</p> <p>These two lines are in your viewDidLoad method</p> <pre><code>_carouselItems = [[NSMutableArray alloc] initWithCapacity:1]; _categorymAr = [[NSMutableArray alloc] initWithCapacity:1]; </code></pre> <p>But: <code>viewDidLoad:</code> is called every time the view is loaded by it's controller. If the controller purges the view (for example after a memory warning), at the second viewDidLoad your <code>_carouselItems</code> and <code>_categorymAr</code> instance variables will lost the reference to the previously created NSMutableArray, causing a leak</p> <p>So, change that lines and use the syntesized setters:</p> <pre><code>self.carouselItems = [[[NSMutableArray alloc] initWithCapacity:1] autorelease]; self.categorymAr = [[[NSMutableArray alloc] initWithCapacity:1] autorelease]; </code></pre> <p>the syntesized setter is configured to release the previous object before assignin a new one.</p> <p>However: it's possible that you have another leak. If you can reproduce the leak simply (if I understand, the leak appears simply moving from a VC to another), you can use the "heapshot" function of instruments.</p> <p>Assuming that your leak appears moving from the first VC to the second and coming back:</p> <ul> <li>open instruments with the allocations tool</li> <li>go from the first VC to the second and come back.</li> <li>press "mark heap" on the left. A line will appear.</li> <li>go again from the first VC to the second and come back.</li> <li>press "heapshot" again</li> <li>do this several times (9-10)</li> </ul> <p>the heapshot tool takes a "snapshot" of the living objects at the time you pushed the button and shows you only the difference. If there are 2-3 new objects, you will see it in the list.</p> <p>This is a good starting point to investigate a leak. Look at the attached image:</p> <p><img src="https://i.stack.imgur.com/vRKsk.png" alt="Heapshot analysis"></p> <p>Consider that you must mark the heap several time and discriminate "false positive" by looking at the object created, in my example you can se a possible leak (heapshot5, 1,66KB), but after looking at the content it's not --> it was a background task that started in that moment.</p> <p>Moreover, delays of the autorelease pool and the cache of some UIKit objects can show something in the heapshot, this is why I say to try it several times.</p>
    singulars
    1. This table or related slice is empty.
    1. POGetting memory leak in UIKit?
      singulars
      1. PTQuestion
    1. PTAnswer
    1. USLombaX
    1. USLombaX
    plurals
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. POGetting memory leak in UIKit?
      singulars
      1. PTQuestion
    1. This table or related slice is empty.
    1. VO
      singulars
      1. PO
      1. This table or related slice is empty.
      1. VTUpMod
    2. VO
      singulars
      1. PO
      1. This table or related slice is empty.
      1. VTBountyClose
    3. VO
      singulars
      1. PO
      1. This table or related slice is empty.
      1. VTAcceptedByOriginator
    1. COUsing the setters is good, but you need to use an autoreleased-version of the `NSMutableArray` creation, or it's still a leak. `self.carouselItems = [NSMutableArray array];` Note that it is almost always a mistake to use `initWithCapacity:` (especially such a low capacity). (As noted in previous comments, ARC is the right answer in any case.)
      singulars
      1. PO
      1. USRob Napier
    2. COyou are right, he needs the autorelease because the setter configured as "retain" sends another retain to the new object. I correct the post. About the initWithCapacity and the use of ARC (which I can suggest :-) I agree too, but (about ARC) I think that investigate about a leak and learn some concepts of MRC is always a good practice ;-) so I suggest the poster to migrate to ARC only when the leak has been found!
      singulars
      1. PO
      1. USLombaX
    3. COThanks guys.As you all suggested, I converted my code to ARC. Now no memory leaks.Also should follow other suggestions to manage low memory warning.
      singulars
      1. PO
      1. USNSUserDefault
 

Querying!

 
Guidance
A row detail

Detail views are divided into sections. All the information in the data section comes from columns in the selected row. The other sections display data from other, related rows.

Related data can be related in a to-one or a to-many fashion. Captions of data related in a to-many fashion link to a list view showing a filtered view of the table.

Try moving around until you find a non-empty to-many entry and click on the label to get to one. You can move back to the root by clicking on the database name in the header.

SQuiL has stopped working due to an internal error.

If you are curious you may find further information in the browser console, which is accessible through the devtools (F12).

Reload