UIImageWriteToSavedPhotosAlbum showing memory leak with iPhone connected to Instruments

Question

Hi,

I'm using version 3.0.1 of the SDK.

With the iPhone connected to Instruments I'm getting a memory leak when I call UIImageWriteToSavedPhotosAlbum.

Below is my code:

    NSString *gnTmpStr = [NSString stringWithFormat:@"%d", count];

UIImage *ganTmpImage = [UIImage imageWithContentsOfFile:[[NSBundle mainBundle] pathForResource:gnTmpStr ofType:@"jpg"]];

// Request to save the image to camera roll
UIImageWriteToSavedPhotosAlbum(ganTmpImage, self, @selector(imageSavedToPhotosAlbum:didFinishSavingWithError:contextInfo:), nil);

and the selector method

        - (void)imageSavedToPhotosAlbum:(UIImage *)image didFinishSavingWithError:(NSError *)error contextInfo:(void *)contextInfo {
NSString *message;
 NSString *title;
 if (!error)
 {
  title = @"Wallpaper";
  message = @"Wallpaper Saved";

 }
 else
 {
  title = @"Error";
  message = [error description];

 }
 UIAlertView *alert = [[UIAlertView alloc]
        initWithTitle:title
        message:message 
        delegate:self
        cancelButtonTitle:@"OK"
        otherButtonTitles:nil];
 [alert show];
 [alert release];

    }

Am I forgetting to release something once the image has been saved and the selector method imageSavedToPhotosAlbum is called? Or is there a possible known issue with UIImageWriteToSavedPhotosAlbum?

Here is the stack trace from Instruments:

Leaked Object: GeneralBlock-3584
size: 3.50 KB

       30 MyApp start
      29 MyApp main /Users/user/Desktop/MyApp/main.m:14
      28 UIKit UIApplicationMain
      27 UIKit -[UIApplication _run]
      26 GraphicsServices GSEventRunModal
      25 CoreFoundation CFRunLoopRunInMode
      24 CoreFoundation CFRunLoopRunSpecific
      23 GraphicsServices PurpleEventCallback
      22 UIKit _UIApplicationHandleEvent
      21 UIKit -[UIApplication sendEvent:]
      20 UIKit -[UIWindow sendEvent:]
      19 UIKit -[UIWindow _sendTouchesForEvent:]
      18 UIKit -[UIControl touchesEnded:withEvent:]
      17 UIKit -[UIControl(Internal) _sendActionsForEvents:withEvent:]
      16 UIKit -[UIControl sendAction:to:forEvent:]
      15 UIKit -[UIApplication sendAction:toTarget:fromSender:forEvent:]
      14 UIKit -[UIApplication sendAction:to:from:forEvent:]
      13 CoreFoundation -[NSObject performSelector:withObject:withObject:]
      12 UIKit -[UIBarButtonItem(Internal) _sendAction:withEvent:]
      11 UIKit -[UIApplication sendAction:to:from:forEvent:]
      10 CoreFoundation -[NSObject performSelector:withObject:withObject:]
       9 MyApp -[FlipsideViewController svPhoto] /Users/user/Desktop/MyApp/Classes/FlipsideViewController.m:218
       8  0x317fa528
       7  0x317e3628
       6  0x317e3730
       5  0x317edda4
       4  0x3180fc74
       3 Foundation +[NSThread detachNewThreadSelector:toTarget:withObject:]
       2 Foundation -[NSThread start]
       1 libSystem.B.dylib pthread_create
       0 libSystem.B.dylib malloc

I did a test with a new project and only added this code below in the viewDidLoad:

NSString *gnTmpStr = [NSString stringWithFormat:@"DefaultTest"];
UIImage *ganTmpImage = [UIImage imageWithContentsOfFile:[[NSBundle mainBundle] pathForResource:gnTmpStr ofType:@"png"]];
// Request to save the image to camera roll 
UIImageWriteToSavedPhotosAlbum(ganTmpImage, nil, nil, nil);

The same leak shows up right after the app loads

Thank you for the help.

Bryan

Answer 1

A quick look doesn't reveal any objects that you own and need to release. Look through your code for places where you get a new object, alloc, copy or retain. Those are the objects you have to worry about releasing.

Answer 2

I'm having the same problem with iPhone 3.1.

Answer 3

I think I solved this one. It has to do with the contextInfo. Here's what I did and the memory leak no longer seems to appear:

Note that you have to define the object type of the contextInfo...

-(IBAction)savePhoto{

UIImageWriteToSavedPhotosAlbum([UIImage imageNamed:imageName], self, @selector(image:didFinishSavingWithError:contextInfo:), nil);

//MEMORY LEAK HERE }

• (void)image:(UIImage *)image didFinishSavingWithError:(NSError *)error contextInfo:(NSDictionary *)contextInfo {
  if (error != NULL){ UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"Error" message:@"Image was not saved, sorry" delegate:nil cancelButtonTitle:@"OK" otherButtonTitles:nil]; [alert show]; [alert release]; } else { //no errors

  //tell the user photo ok:
  UIAlertView *alert = [[UIAlertView alloc] initWithTitle:contents message:@"Image was saved to your photos" delegate:nil cancelButtonTitle:@"OK" otherButtonTitles:nil];
  [alert show];
  [alert release];
  

  } if (image !=NULL){ [image release]; image=nil; } if(contextInfo !=NULL){ [contextInfo release]; contextInfo=nil; }

}