Objective-C: Memory leak with CGDataProviderCopyData

Question

With the help of the instrument, it is shown that CGDataProviderCopyData is using too much memory. How to fix the issue?

-(UIImage*)imageNamed:(NSString*)name {

UIImage *uiimage = [UIImage imageNamed:name];


CGImageRef originalImage = [uiimage CGImage];
CFDataRef imageData = CGDataProviderCopyData(
         CGImageGetDataProvider(originalImage));
CGDataProviderRef imageDataProvider = CGDataProviderCreateWithCFData(imageData);
CFRelease(imageData);
CGImageRef image = CGImageCreate(
         CGImageGetWidth(originalImage),
         CGImageGetHeight(originalImage),
         CGImageGetBitsPerComponent(originalImage),
         CGImageGetBitsPerPixel(originalImage),
         CGImageGetBytesPerRow(originalImage),
         CGImageGetColorSpace(originalImage),
         CGImageGetBitmapInfo(originalImage),
         imageDataProvider,
         CGImageGetDecode(originalImage),
         CGImageGetShouldInterpolate(originalImage),
         CGImageGetRenderingIntent(originalImage));
CGDataProviderRelease(imageDataProvider);



return [UIImage imageWithCGImage:image];
}

Please check the code in the screenshot. Do you not see the screenshot? — Abdul Jamil, Mar 10 '17 at 16:40
Do not post code as an image. Copy and paste the actual code. — rmaddy, Mar 10 '17 at 16:50
Code is added now. The screenshot is from instrument showing the actual problem. — Abdul Jamil, Mar 10 '17 at 16:56
@AbdulJamil How large is the image for the imageData variable? How much memory are you expecting the imageData variable to use? — Swift Dev Journal, Mar 10 '17 at 19:13
What's the point of all of this code? Why create a new image this way from the image loaded by `imageNamed:`? — rmaddy, Mar 10 '17 at 21:43

rmaddy · Answer 1 · 2019-04-08T16:42:42.443

The problem is that you never release image.

Update your code as follows:

-(UIImage*)imageNamed:(NSString*)name {
    UIImage *uiimage = [UIImage imageNamed:name];

    CGImageRef originalImage = [uiimage CGImage];
    CFDataRef imageData = CGDataProviderCopyData(
             CGImageGetDataProvider(originalImage));
    CGDataProviderRef imageDataProvider = CGDataProviderCreateWithCFData(imageData);
    CFRelease(imageData);
    CGImageRef image = CGImageCreate(
             CGImageGetWidth(originalImage),
             CGImageGetHeight(originalImage),
             CGImageGetBitsPerComponent(originalImage),
             CGImageGetBitsPerPixel(originalImage),
             CGImageGetBytesPerRow(originalImage),
             CGImageGetColorSpace(originalImage),
             CGImageGetBitmapInfo(originalImage),
             imageDataProvider,
             CGImageGetDecode(originalImage),
             CGImageGetShouldInterpolate(originalImage),
             CGImageGetRenderingIntent(originalImage));
    CGDataProviderRelease(imageDataProvider);

    UIImage *result = [UIImage imageWithCGImage:image];
    CGImageRelease(image);

    return result;
}

I already tried to release the image but it introduces a crash. Also it is CGImageRelease(image); not CFImageRelease(image); — Abdul Jamil, Mar 11 '17 at 05:18

Abdul Jamil · Answer 2 · 2017-04-04T05:37:22.117

Finally, I was able to solve this. Actually there were few extra unnecessary steps which were causing memory leaks. Here is the updated function:

-(UIImage*)imageNamed:(NSString*)name {

 UIImage *uiimage = [UIImage imageNamed:name];


 CGImageRef originalImage = [uiimage CGImage];

 CGImageRef image = CGImageCreate(
     CGImageGetWidth(originalImage),
     CGImageGetHeight(originalImage),
     CGImageGetBitsPerComponent(originalImage),
     CGImageGetBitsPerPixel(originalImage),
     CGImageGetBytesPerRow(originalImage),
     CGImageGetColorSpace(originalImage),
     CGImageGetBitmapInfo(originalImage),
     CGImageGetDataProvider(originalImage),
     CGImageGetDecode(originalImage),
     CGImageGetShouldInterpolate(originalImage),
     CGImageGetRenderingIntent(originalImage));

 return [UIImage imageWithCGImage:image];
}

CGImageGetDataProvider(originalImage) returns CGDataProviderRef and that is required as 8th parameter in CGImageCreate function. Above steps to copy image data and then creating CGDataProviderRef were unnecessary.

Objective-C: Memory leak with CGDataProviderCopyData

2 Answers2