Potential leak IPhone App - objective-c

HarrisAnnotation *harrisAnnotation = [[HarrisAnnotation alloc] init];
[self.mapAnnotations insertObject:harrisAnnotation atIndex:0];
[harrisAnnotation release];
Running analyze on project show
Potential leak of an object
for
harrisAnnotation

Never mind, I'm not used to using Xcode. It was the line below.

Related

Memory Leak when running: [[GKMatchmakerViewController alloc] initWithMatchRequest:request]

I'm testing my Objective C project for memory leaks using xCode Instruments tool.
The following lines (in my procedure to find matches in Game Center) are generating a Memory Leak:
GKMatchRequest *request = [[GKMatchRequest alloc] init];
request.minPlayers = minPlayers;
request.maxPlayers = maxPlayers;
GKMatchmakerViewController *mmvc = [[GKMatchmakerViewController alloc] initWithMatchRequest:request];
According to the Instruments Stack Trace, the Leaked Object is "GKMatchRequest".
Responsible Library: GameCenterFoundation
Responsible Frame: -[GKMatchRequest copyWithZone:]
I'm using ARC, so it should not be required to include 'Autorelease' right after the 'request' as suggested in some forums reporting a similar issue (i.e.: https://forums.coronalabs.com/topic/59315-ios-native-plugin-objective-c-memory-leak/).
How to avoid this memory leak in my code ?

Memory leak in image

I'm using the profiler in xcode 4 to determinate if I have any memory leaks. I didn't have this leak before, but with xcode 5 I have this one.
I'm trying to set an image for the tab item of my `UIViewController and the profiler marks this line :
image = [[UIImage alloc] initWithContentsOfFile:imgPath]; <<=== Leak : 9.1%
This is part of my code I don't understand why. What's the best way to resolve this issue?
NSString *imgPath;
UIImage *image;
IBNewsViewController *newsView = [[IBNewsViewController alloc] initWithURL:[tvLocal urlFlux] title:#"News" isEmission:NO];
[newsView setTitle:#"News"];
imgPath = [[NSBundle mainBundle] pathForResource:"news" ofType:#"png"];
image = [[UIImage alloc] initWithContentsOfFile:imgPath]; <<=== Leak : 9.1%
newsView.tabBarItem.image = image;
[image release];
image = nil;
UINavigationController* navNew = [[UINavigationController alloc] initWithRootViewController:newsView];
[newsView release];
newsView = nil;
EDIT:
No leak on iOS6.
Why it's leak on iOS7?
You should switch to the autoreleasing imageNamed: method. This has the added benefit of system level cacheing of the image.
NSString *imgPath;
UIImage *image;
IBNewsViewController *newsView = [[IBNewsViewController alloc] initWithURL:[tvLocal urlFlux] title:#"News" isEmission:NO];
[newsView setTitle:#"News"];
image = [UIImage imageNamed: #"news"];
newsView.tabBarItem.image = image;
UINavigationController* navNew = [[UINavigationController alloc] initWithRootViewController:newsView];
[newsView release];
newsView = nil;
To make life easier on yourself I'd switch your project to use ARC so you have less to worry about WRT memory management.
Replace this line
image = [[UIImage alloc] initWithContentsOfFile:imgPath];
With
image = [UIImage imageWithContentsOfFile:imgPath];
and check once.
First, switch to ARC. There is no single thing you can do on iOS that will more improve your code and remove whole classes of memory problems with a single move.
Beyond that, the code above does not appear to have a leak itself. That suggests that the actual mistake is elsewhere. There are several ways this could happen:
You're leaking the IBNewsViewController somewhere else
IBNewsViewController messes with its tabBarItem incorrectly and leaks that
You're leaking the UINavigationController somewhere else
You're retaining the tabBarItem.image somewhere else and failing to release it
Those are the most likely that I would hunt for. If you're directly accessing ivars, that can often cause these kinds of mistakes. You should use accessors everywhere except in init and dealloc. (This is true in ARC, but is absolutely critical without ARC.)
Leak detection is not perfect. There are all kinds of "abandoned" memory that may not appear to be a leak. I often recommend using Heapshot (now "Generation") analysis to see what other objects may be abandoned; that may give you a better insight into this leak.
Why differences in iOS 6 vs iOS 7? I suspect you have the same problem on iOS 6, but it doesn't look like a "leak", possibly because there is something caching the image that was removed in iOS 7. The cache pointer may make it look like it's not a leak to Instruments.
Speaking of which, do make sure to run the static analyzer. It can help you find problems.
And of course, switch to ARC.

NSOperation subclass release make Instruments crash

I ran instruments on my Mac OS X application in Xcode 4.5. I have two NSOperation dependent subclasses that I forgot to release after adding them in a process queue. So I released them just after adding them in the queue. The application works great. I profiles it on Instruments but it crashes.
processQueue = [[NSOperationQueue alloc] init];
NSUInteger max = [[NSUserDefaults standardUserDefaults] integerForKey:#"jobsKey"];
processQueue.maxConcurrentOperationCount = max;
GeocacheDownloadOperation * downloadOp = [[GeocacheDownloadOperation alloc] initWithGeocache:cache InPath:directoryPath withDelegate:self];
GeocacheJPGConversionOperation * conversionOp = [[GeocacheJPGConversionOperation alloc] initWithCache:cache WithPath:directoryPath WithDelegate:self];
[conversionOp addDependency:downloadOp];
[processQueue addOperation:downloadOp];
[processQueue addOperation:conversionOp];
[downloadOp release];
[conversionOp release]; //This line makes Instruments crash
Instruments crash when I want to release the last operation (see on code) but the application seems to work great.
Did someone have a suggestion ? Is it an Instruments bug or did I code something wrong ?
My guess is that conversionOp releases every dependency (so downloadOp in this case) when deallocated. So you call [conversionOp release] after both operations are finished (and this depends on how the threads are scheduled), so you over-release downloadOp.
I found the error but I can't explain why it was working alone and not in Instruments. I used a released variable in the NSOperation subclasses, that I released the second times in the dealloc function of the NSOperation subclasses. Now, I don't override [super dealloc] anymore in the NSOperationsubclasses and it works.

Can I use autorelease to fix this memory leak?

I have a memory leak in my iPhone app. I added Google AdMob to my app using sample code downloaded from Google. However, I was having a hard time getting it into testing mode so I added an extra variable as follows:
GADRequest *r = [[GADRequest alloc] init];
r.testing = YES;
[bannerView_ loadRequest:r];
I found the memory leak using Instruments. Instruments does not lead me to this line of code, it just dumps me in the main.m file. However, when I comment out the code relating to AdMob the leak goes away and I know enough to see that I haven't taken care of releasing this new variable. I just don't know exactly how I should set about releasing it. The variable r is not addressed in the header file so this is all the code that deals with it.
I tried adding:
- (void)dealloc {
[r release];
....
}
but that caused a build error saying "'r' undeclared". That's weird because it looks to me like I'm declaring r in the first quoted line above but I guess that's wrong. Any help would be much appreciated. I really have tried to educate myself about memory leaks but I still find them very confusing.
Just add [r release]; right below the code:
GADRequest *r = [[GADRequest alloc] init];
r.testing = YES;
[bannerView_ loadRequest:r];
[r release];
The variable r is declared only in that section of your code, so that's where it should be released. The point of releasing is to get rid of it as soon as you no longer need it, so the above should work perfectly for you.
If your r is locally declared (as it seems, judging from your snippet), then it cannot be accessed from outside its scope (here: the method it was declared in).
You either need to make it accessible within your class instance by declaring it an ivar.
Declaring it an ivar would look like this:
#interface YourClass : SuperClass {
GADRequest *request;
}
//...
#end
You then change your code to this:
request = [[GADRequest alloc] init];
request.testing = YES;
[bannerView_ loadRequest:request];
Also don't forget to release it in dealloc:
- (void)dealloc {
[request release];
//...
}
However this is not what you want in this situation (I've just included it to clarify why you get the warning about r not being declared).
You (most likely) won't need request any second time after your snippet has run, thus storing it in an ivar will only needlessly occupy RAM and add unwantd complexity to your class. Stuff you only need at the immediate time after its creation should be taken care of (released) accordingly, that is within the very same scope.
What you'll actually want to do is simply (auto)release it, properly taking care of it.
Keep in mind though that your loadRequest: will need to take care of retaining r for as long as it needs it. Apple's implementation does this, of course. But you might want to write a similar method on your own one day, so keep this in mind then.
GADRequest *r = [[GADRequest alloc] init];
r.testing = YES;
[bannerView_ loadRequest:r];
[r release]; //or: [r autorelease];
OP here. Thanks for all the detailed and thoughtful responses. This has definitely helped get a better handle on memory management. I did exactly as recommended, adding [r release]; right below the posted code. However, I still have a leak. I have isolated it to a single line of code. The following leaks:
GADRequest *r = [[GADRequest alloc] init];
r.testing = YES;
[bannerView_ loadRequest:r];
[r release];
The following does not leak:
GADRequest *r = [[GADRequest alloc] init];
r.testing = YES;
// [bannerView_ loadRequest:r];
[r release];
I figure I'm changing the retain count on bannerView with the loadRequest but I don't know how to fix it. I tried a [bannerView_ release] immediately after the [r release]; line (i.e. releasing locally) but that didn't work. I didn't expect it to because bannerView_ is declared elsewhere. I tried [bannerView_ release]; in the dealloc method but that didn't work. I also tried [bannerView_ autorelease]; locally. The wise heads at Google put [bannerView_ release]; in the ViewDidUnload method.
It's possible that Instruments is just messing with my head. The leak appears after about 10 seconds but the app performs well and the amount of memory leaked doesn't seem to be spirally upwards as the app continues to run. Is there such a thing as a benign memory leak?
Thanks again for your help,
Dessie.

Problem with memory management

Here is a sample code, i am trying to import contacts for the iphone to my app.
-(IBAction)import_Clicked:(id)sender{
ABPeoplePickerNavigationController *picker = [[ABPeoplePickerNavigationController alloc] init]; //leaking here
picker.peoplePickerDelegate = self;
// Display only a person's phone, email, and birthdate
NSArray *displayedItems = [NSArray arrayWithObjects:[NSNumber numberWithInt:kABPersonPhoneProperty],
[NSNumber numberWithInt:kABPersonEmailProperty],
[NSNumber numberWithInt:kABPersonBirthdayProperty], nil];
picker.displayedProperties = displayedItems;
[self presentModalViewController:picker animated:YES];
[picker release];}
i ran this on instruments and it shows me 100% leak at line where i alloc abpeoplepickernavigationcontroller. i realsed it after persentmodalviewcontroller. where else could i go wrong.
Any Help , Please.....
There seems to be a strange SDK bug at large here... Have a read of the official Apple dev forums here for more information and a solution.
Strange, that doesn't looks like a leak to me, heard that Instruments (rarely) report false leaks.
EDIT: forget what follows and read bbum comment instead :)
Could you please try removing [picker release] and then use autorelease instead :
BPeoplePickerNavigationController *picker = [[[ABPeoplePickerNavigationController alloc] init] autorelease];
Then see if instruments still report a leak? If not, keep your original code and ignore that false alert...
That is almost the same but using NSAutoReleasePool might change Instruments behavior.
Please also note that explicitly releasing like you did is a more cleaner approach than autoreleasing.