Help resolving memory leak

[keiffer6]

I have a class named Ephemerides that does large amount of calculations and then returns an array of the results. I call this class from one of my view controllers in viewWillAppear. Everything works fine, but when I use instruments to check for leaks this always shows up as a leak. I have tried everything I can think of to release the object but so far I have had no luck.

Here is the relevant viewWillAppear code that calls the class:

    [self setEphemText:[[Ephemerides alloc] initWithName:[infoText objectAtIndex:16] 
                                                      qq:[[infoText objectAtIndex:6] doubleValue] 
                                                       e:[[infoText objectAtIndex:7] doubleValue] 
                                                       w:[[infoText objectAtIndex:8] doubleValue] 
                                                      om:[[infoText objectAtIndex:9] doubleValue] 
                                                       I:[[infoText objectAtIndex:10] doubleValue] 
                                                 yr_peri:[[infoText objectAtIndex:3] doubleValue] 
                                                 mo_peri:[[infoText objectAtIndex:4] doubleValue] 
                                                day_peri:[[infoText objectAtIndex:5] doubleValue] 
                                                 abs_mag:[[infoText objectAtIndex:14] doubleValue] 
                                                   mag_n:[[infoText objectAtIndex:15] doubleValue] 
                                                   coord:coordRA 
                                                   steps:numberSteps 
                                                interval:numberInterval]];

    [self setTableDataSource:ephemText];
     
    [self.infoTable reloadData];

infoText is an array that is loaded from a SQLite table prior to this and contains the necessary variables for the Ephemerides class to do the calculations.

Whenever I load that view controller in the app, I get this from Instruments:

#	Address	Category	Event Type	RefCt	Timestamp	Size	Responsible Library	Responsible Caller
0	0xa9399e0	Ephemerides	Malloc	1	00:08.502.430	16	Comet	-[CometEphem getEphemerides]

I do have [Ephemerides release]; and [ephemText release]; in my dealloc. That does not seem to help any. If I comment out the section of code shown above, then the memory leak goes away. So I am pretty certain that the problem is with that section of code.

I am relatively new to Xcode, but I understand the concepts of releasing memory. When I run my app in the simulator this is the only leak I have and I just can't figure out how to resolve it. Each time that controller loads I get another 16 bytes. My guess is that I should be going a about calling the Ephemerides class differently. Any help or direction would be greatly appreciated.

Keith

[MattW]

I'd guess that your dealloc method is never getting called. Put a breakpoint on it and see if it ever hits.

[JasonR]

When you call setEphemText: with an object you created with alloc on the same line, the object is getting retained twice, and only released once. Read BrianSlick's link about properties to understand why this is wrong, and how to fix it. You'll see his name to the right of this post, listed as Top Poster. Then you'll see his property link in his signature.

[TheStuFactor]

Your Ephemerides instance is never being released.

Set your Ephemerides as an object before you call '[self setEphemText]' and then release that object after your method call.

  // instantiate an instance of Ephemrides
  Ephemerides *eph = [[Ephemerides alloc] initWithName:....];
  
  // call your method
  [self setEphemText: eph];

  // release the instance
  [eph release];

  .
  .
  .

[keiffer6]

Originally Posted by JasonR

When you call setEphemText: with an object you created with alloc on the same line, the object is getting retained twice, and only released once. Read BrianSlick's link about properties to understand why this is wrong, and how to fix it. You'll see his name to the right of this post, listed as Top Poster. Then you'll see his property link in his signature.

Thanks for pointing me to BrianSlick's link. That is really good information. I have read through it and made the following changes, but I still get the same leak.

    NSArray *tempEphem = [[Ephemerides alloc] initWithName:[infoText objectAtIndex:16] 
                                                            qq:[[infoText objectAtIndex:6] doubleValue] 
                                                             e:[[infoText objectAtIndex:7] doubleValue] 
                                                             w:[[infoText objectAtIndex:8] doubleValue] 
                                                            om:[[infoText objectAtIndex:9] doubleValue] 
                                                             I:[[infoText objectAtIndex:10] doubleValue] 
                                                       yr_peri:[[infoText objectAtIndex:3] doubleValue] 
                                                       mo_peri:[[infoText objectAtIndex:4] doubleValue] 
                                                      day_peri:[[infoText objectAtIndex:5] doubleValue] 
                                                       abs_mag:[[infoText objectAtIndex:14] doubleValue] 
                                                         mag_n:[[infoText objectAtIndex:15] doubleValue] 
                                                         coord:coordRA 
                                                         steps:numberSteps 
                                                      interval:numberInterval];
    [self setEphemText: tempEphem];
    [tempEphem release], tempEphem = nil;

#	Address	Category	Event Type	RefCt	Timestamp	Size	Responsible Library	Responsible Caller
0	0x7c464b0	Ephemerides	Malloc	1	00:16.883.589	16	Comet	-[CometEphem getEphemerides]

Am I just missing something?

[keiffer6]

Originally Posted by TheStuFactor

Your Ephemerides instance is never being released.

Set your Ephemerides as an object before you call '[self setEphemText]' and then release that object after your method call.

  // instantiate an instance of Ephemrides
  Ephemerides *eph = [[Ephemerides alloc] initWithName:....];
  
  // call your method
  [self setEphemText: eph];

  // release the instance
  [eph release];

  .
  .
  .

Stu,

That is basically what I have at this point but I still get the leak.

The big difference is that I have NSArray *tempEphem where as you say to do Ephemerides *tempEphem. I have tried this but I always get an "Incompatible pointer types initializing 'Ephemerides *' with an expression of type 'NSArray *'"



Keith

[keiffer6]

Sorry, sometimes I can just be a little slow

I modified my code to this:

    Ephemerides *eph = [[Ephemerides alloc] init];
    NSArray *tempEphem = [eph initWithName:[infoText objectAtIndex:16] 
                   qq:[[infoText objectAtIndex:6] doubleValue] 
                    e:[[infoText objectAtIndex:7] doubleValue] 
                    w:[[infoText objectAtIndex:8] doubleValue] 
                   om:[[infoText objectAtIndex:9] doubleValue] 
                    I:[[infoText objectAtIndex:10] doubleValue] 
              yr_peri:[[infoText objectAtIndex:3] doubleValue] 
              mo_peri:[[infoText objectAtIndex:4] doubleValue] 
             day_peri:[[infoText objectAtIndex:5] doubleValue] 
              abs_mag:[[infoText objectAtIndex:14] doubleValue] 
                mag_n:[[infoText objectAtIndex:15] doubleValue] 
                coord:coordRA 
                steps:numberSteps 
             interval:numberInterval];
                              
    [self setEphemText: tempEphem];
    [eph release], eph = nil;
    [tempEphem release], tempEphem = nil;

That appears to have solved my leak problem. Thank you very much for all the help and direction.