iOS Memory

[illwi11]

Instruments is saying that there is a leak at the line: NSMutableDictionary *sceneWithDistance = [[NSMutableDictionary alloc] initWithCapacity:numKeys];


Why? I release the object - sceneWithDistance.

Why? We release sceneWithDistance.

- (NSMutableArray *) sortByDistance: (NSMutableArray *) toSort {
         ....
        NSMutableDictionary *sceneWithDistance = [[NSMutableDictionary alloc] initWithCapacity:numKeys];
        .....
       
        [sorted addObject:sceneWithDistance];
       
        [sceneWithDistance release];
}

 

[drivefast]

[sorted addObject:sceneWithDistance];

this holds a reference to your sceneWithDistance object. memory allocation in objective-c works differently from how perhaps you expect it to. in the faq of this forum there is a link to a decent article that explains the memory management in objective-c, it's a lecture i would recommend.

 

[illwi11]

One more memory leak

Thanks for the reply. I do understand the reference counting memory management. I do release the variable "sorted" later so the reference count of sceneWithDistance should also be decremented by 1. I'll look into it some more. Thank you for the response.

I have another memory leak that is very confusing.

Instruments is saying that there is a leak at this line: userCredentials = [NSKeyedUnarchiver unarchiveObjectWithFileath];
It says the leaked object is a NCSFString - the only object that is a string is path. However when I release this object ([path release]) , the application completely crashes on startup.

- (NSDictionary *) retrieveUserCredentials{

    NSString *path=[NSTemporaryDirectory() stringByAppendingString:@"user.txt"];
   
    NSDictionary *userCredentials;
   
    userCredentials = [NSKeyedUnarchiver unarchiveObjectWithFile:path];
...
}

Any ideas?

 

[beachdog]

It says the leaked object is a NCSFString - the only object that is a string is path.

To me it seems like you are handling 'path' correctly -- you are getting back an auto-released string and thus you should *not* explicitly release it.

What about the string returned from NSTemporaryDirectory() ? Could that be the leak?

 

[caveman_uk]

Don't assume all Apple code is leak free.

 

[PhoneyDeveloper]

path and NSTemporaryDirectory() are not the source of the leak. What is the contents of the userCredentials dictionary? Probably the leak is a string held in that dictionary.