Memory (Core Foundation/Objective-C) - Potential leak of an object on...

[jlerma1]

Hi there,

I am very new to Xcode dev, but guess what? I did build an entire application with some sounds and switching views and believe it or not, it has value. Everything runs beautiful and it looks great with no real issues except for this error:


"Memory (Core Foundation/Objective-C) - Potential leak of an object..."

I have attched 2 screenshots. The top image is from the window generated on the left side of Xcode (see I don't even know what thats' called yet) and the bottom one is my code from the .M file.

I have 4 sound files which are .wav's and pretty much under 5 seconds. My app never crashes.

So here are my questions, how do I get rid of these errors? I know this is memory management related. if anyone gives assistance, please be very specific like by telling me to go to the .m or the appdelegate and do so and so. Unfortunately, I need my hand held on this question. I am learning the coding parlance but not there yet.


My other question is this; is this error grounds fro rejection, even if the simulator says it generates with no issues?

I am close to being able to submit my app and I want everything to be as perfect as possible.

Thank you in advance to anyone who can walk me through this.

Much Obliged,

Jared

[smithdale87]

That screenshot is unreadable, can you just paste some of the code where you are getting that warning.

[jlerma1]

Originally Posted by smithdale87

That screenshot is unreadable, can you just paste some of the code where you are getting that warning.

You are right. Sorry about that and thank you for reviewing this so quickly.

//The error message shows up on 4 of the same lines listed below

"AudioServicesPlaySystemSound(soundID);"

The 2 part error message for all 4 of the same lines reads:

//Here is the main message

Potential leak of an object allocated on line 88 and stored into 'soundFileURLRef'

//here are the sub messages

Call to function 'CFBundleCopyResourceURL' returns a Core Foundation object with a +1 retain count (owning reference)

//AND

Object allocated on line 88 and stored into 'soundFileURLRef' is not referenced later in this execution path and has a retain count of +1 (object leaked)

//Below is the code in question

-(IBAction)Sound1 {
CFBundleRef mainBundle = CFBundleGetMainBundle();
CFURLRef soundFileURLRef;
soundFileURLRef = CFBundleCopyResourceURL(mainBundle, (CFStringRef) @"Sound1", CFSTR ("wav"), NULL);

UInt32 soundID;
AudioServicesCreateSystemSoundID(soundFileURLRef, &soundID);
AudioServicesPlaySystemSound(soundID);
}

-(IBAction)Sound2 {
CFBundleRef mainBundle = CFBundleGetMainBundle();
CFURLRef soundFileURLRef;
soundFileURLRef = CFBundleCopyResourceURL(mainBundle, (CFStringRef) @"Sound2, CFSTR ("wav"), NULL);

UInt32 soundID;
AudioServicesCreateSystemSoundID(soundFileURLRef, &soundID);
AudioServicesPlaySystemSound(soundID);
}

-(IBAction)Sound3 {
CFBundleRef mainBundle = CFBundleGetMainBundle();
CFURLRef soundFileURLRef;
soundFileURLRef = CFBundleCopyResourceURL(mainBundle, (CFStringRef) @"Sound3", CFSTR ("wav"), NULL);

UInt32 soundID;
AudioServicesCreateSystemSoundID(soundFileURLRef, &soundID);
AudioServicesPlaySystemSound(soundID);
}

-(IBAction)Sound4 {
CFBundleRef mainBundle = CFBundleGetMainBundle();
CFURLRef soundFileURLRef;
soundFileURLRef = CFBundleCopyResourceURL(mainBundle, (CFStringRef) @"Sound4", CFSTR ("wav"), NULL);

UInt32 soundID;
AudioServicesCreateSystemSoundID(soundFileURLRef, &soundID);
AudioServicesPlaySystemSound(soundID);
}

I hope this helps. I would provide a better screenshot but apparently the thread won't allow it.


Thanks for your help in advance.

Jared

[Duncan C]

Originally Posted by jlerma1

You are right. Sorry about that and thank you for reviewing this so quickly.

//The error message shows up on 4 of the same lines listed below

"AudioServicesPlaySystemSound(soundID);"

The 2 part error message for all 4 of the same lines reads:

//Here is the main message

Potential leak of an object allocated on line 88 and stored into 'soundFileURLRef'

//here are the sub messages

Call to function 'CFBundleCopyResourceURL' returns a Core Foundation object with a +1 retain count (owning reference)

//AND

Object allocated on line 88 and stored into 'soundFileURLRef' is not referenced later in this execution path and has a retain count of +1 (object leaked)

//Below is the code in question

-(IBAction)Sound1 {
CFBundleRef mainBundle = CFBundleGetMainBundle();
CFURLRef soundFileURLRef;
soundFileURLRef = CFBundleCopyResourceURL(mainBundle, (CFStringRef) @"Sound1", CFSTR ("wav"), NULL);

UInt32 soundID;
AudioServicesCreateSystemSoundID(soundFileURLRef, &soundID);
AudioServicesPlaySystemSound(soundID);
}

-(IBAction)Sound2 {
CFBundleRef mainBundle = CFBundleGetMainBundle();
CFURLRef soundFileURLRef;
soundFileURLRef = CFBundleCopyResourceURL(mainBundle, (CFStringRef) @"Sound2, CFSTR ("wav"), NULL);

UInt32 soundID;
AudioServicesCreateSystemSoundID(soundFileURLRef, &soundID);
AudioServicesPlaySystemSound(soundID);
}

-(IBAction)Sound3 {
CFBundleRef mainBundle = CFBundleGetMainBundle();
CFURLRef soundFileURLRef;
soundFileURLRef = CFBundleCopyResourceURL(mainBundle, (CFStringRef) @"Sound3", CFSTR ("wav"), NULL);

UInt32 soundID;
AudioServicesCreateSystemSoundID(soundFileURLRef, &soundID);
AudioServicesPlaySystemSound(soundID);
}

-(IBAction)Sound4 {
CFBundleRef mainBundle = CFBundleGetMainBundle();
CFURLRef soundFileURLRef;
soundFileURLRef = CFBundleCopyResourceURL(mainBundle, (CFStringRef) @"Sound4", CFSTR ("wav"), NULL);

UInt32 soundID;
AudioServicesCreateSystemSoundID(soundFileURLRef, &soundID);
AudioServicesPlaySystemSound(soundID);
}

I hope this helps. I would provide a better screenshot but apparently the thread won't allow it.


Thanks for your help in advance.

Jared

Functions that start with "CF" are Core Foundation functions. They are low-level C based functions.

They use memory management rules that are very similar to Cocoa memory management rules.

Do a search on "get rule" in the XCode help system and read the Memory Management Programming Guide for Core Foundation. The short summary is that methods with get in the name return non-owning refererences that you don't need to release, but methods with "create" or "copy" in the name return owning references, and you need to release them when you are done with them.

The base type of Core Foundation objects is a CFTypeRef. Generally, you call CFRelease() on a Core Foundation object to release it. Some objects have custom release methods, though, so you need to call the specific release method for that object.

In all your code above, you should copy your CFURLRef, use it to create a soundID, and then release the CFURLRef using CFRelease (because you use CFBundleCopyResourceURL, which contains the word copy)

[jlerma1]

Hi Duncan,

As I mentioned in my email, I have no real idea of what I am doing. Would you be able to spell out the .h & .m code and any other thing I would need to visit? Do I need to another framework?

I am sorry to ask this but as I mentioned before, I need my hand held on this error. I appreciate your assistance.

Thanks,

J

[Duncan C]

Originally Posted by jlerma1

Hi Duncan,

As I mentioned in my email, I have no real idea of what I am doing. Would you be able to spell out the .h & .m code and any other thing I would need to visit? Do I need to another framework?

I am sorry to ask this but as I mentioned before, I need my hand held on this error. I appreciate your assistance.

Thanks,

J

Sigh,

Did you even try to understand what I posted?

I'll show you what to do for one of your methods. You need to do the same thing for all of them. That will be up to you to figure out.

-(IBAction)Sound1 {
CFBundleRef mainBundle = CFBundleGetMainBundle();
CFURLRef soundFileURLRef;
soundFileURLRef = CFBundleCopyResourceURL(mainBundle, (CFStringRef) @"Sound1", CFSTR ("wav"), NULL);

UInt32 soundID;
AudioServicesCreateSystemSoundID(soundFileURLRef, &soundID);
CFRelease(soundFileURLRef);
AudioServicesPlaySystemSound(soundID);
}

I added the call to CFRelease in bold.

[jlerma1]

Originally Posted by Duncan C

Sigh,

Did you even try to understand what I posted?

I'll show you what to do for one of your methods. You need to do the same thing for all of them. That will be up to you to figure out.

-(IBAction)Sound1 {
CFBundleRef mainBundle = CFBundleGetMainBundle();
CFURLRef soundFileURLRef;
soundFileURLRef = CFBundleCopyResourceURL(mainBundle, (CFStringRef) @"Sound1", CFSTR ("wav"), NULL);

UInt32 soundID;
AudioServicesCreateSystemSoundID(soundFileURLRef, &soundID);
CFRelease(soundFileURLRef);
AudioServicesPlaySystemSound(soundID);
}

I added the call to CFRelease in bold.

Duncan,

It worked! I did read your post very carefully but there are pieces that were just no connecting. But your code put everything together and in the long run all the pieces will start to fit to better. Your guidance has helped me to take another step and I thank you for that,

Just a few months ago, I have never touched a Mac and now I am a few days away from submitting my app which has great content and a few nice effects that I have put in. Just so you know, i do read the Apple Documentation but I am not good enough to understand some things programmatically.

I really appreciate your assistance with this.

Thanks,

Jared

[Duncan C]

Originally Posted by jlerma1

Duncan,

It worked! I did read your post very carefully but there are pieces that were just no connecting. But your code put everything together and in the long run all the pieces will start to fit to better. Your guidance has helped me to take another step and I thank you for that,

Just a few months ago, I have never touched a Mac and now I am a few days away from submitting my app which has great content and a few nice effects that I have put in. Just so you know, i do read the Apple Documentation but I am not good enough to understand some things programmatically.

I really appreciate your assistance with this.

Thanks,

Jared

Core Foundation is harder to use than UIKit, for sure. NSObject memory management is pretty straightforward.

[macboy]

I was also experiencing the same issue with the memory leak when analyzing the code. I am using xCode 4.3.2.

This one line fixed the issue:
CFRelease(soundFileURLRef);

I think it common to overlook this type of error as just Building and Running does not show this as an error. I have learned to use Analyze to check every project.