This piece of code was split off from a project I am working on. It consistently reproduces a garbage collection error on my Mac OS 10.5.7 and sometimes crashes. I have been looking at it for too long so my question is: does anybody else see why this would give errors when garbage collection is on?
- (void) doCrash: (id) sender
{
NSArray *lURLArray = [ NSArray arrayWithObjects:
#"http://userserve-ak.last.fm/serve/300x300/23621007.jpg",
#"http://userserve-ak.last.fm/serve/300x300/26675609.png",
#"http://userserve-ak.last.fm/serve/300x300/26675609.png",
nil ];
NSString *lImageURL = nil;
for (lImageURL in lURLArray)
{
NSImage *lImage = [[NSImage alloc] initWithContentsOfURL: [NSURL URLWithString: lImageURL]];
NSSize targetSize = NSMakeSize(80,80);
NSImage *newImage = [[NSImage alloc] initWithSize:targetSize];
[newImage lockFocus];
NSRect thumbnailRect = NSMakeRect(0,0,80,80);
NSRect sourceRect = NSMakeRect(0,0,[lImage size].width,[lImage size].height);
[lImage drawInRect: thumbnailRect
fromRect: sourceRect
operation: NSCompositeSourceOver
fraction: 1.0];
[newImage unlockFocus];
}
}
When playing around with the URLs in the lURLArray I get different behavior: sometimes crashes, sometimes the error message.
The garbage collection error message is triggered when the garbage collector is freeing one of the images and goes like this:
reference count underflow for <address>, break on auto_refcount_underflow_error to debug.
Any help is much appreciated,
thanks,
Kristof
This has been confirmed to me by someone from Apple as a bug in OX X 10.5.7.
rdar://problem/6938657
Related
I'm working on a MacOS program in Objective C that needs to produce in-memory thumbnails to send to a server. The following code is used to perform this operation. As the program runs, a leak of about 40mb is induced each time this method is called. I'm missing something really basic, I suspect, but I don't see the source of the problem.
I should add that I've also tried creating one context to use over the life of the program and the problem, if anything, seems somewhat worse.
When I run Instruments, the allocations for the category "VM: ImageIO_JPEG_Data" are growing by one allocation of 40mb each time it's called. The responsible library is "ImageIO" and the responsible caller is "ImageIO_Malloc".
- (void) createPhotoThumbnail
{
NSURL* fileURL = [NSURL fileURLWithPath : _imagePath];
CGColorSpaceRef colorspace = CGColorSpaceCreateDeviceRGB();
CGContextRef bitmapContext = CGBitmapContextCreate(NULL, MAX_THUMB_DIM, MAX_THUMB_DIM, 8, 0,
colorspace, (CGBitmapInfo)kCGImageAlphaNoneSkipLast);
CIContext *ciContext = [CIContext contextWithCGContext: bitmapContext options: #{}];
if (fileURL)
{
CIImage *image = [[CIImage alloc] initWithContentsOfURL: fileURL];
if (image)
{
// scale the image
CIFilter *scaleFilter = [CIFilter filterWithName: #"CILanczosScaleTransform"];
[scaleFilter setValue: image forKey: #"inputImage"];
NSNumber *scaleFactor = [[NSNumber alloc] initWithFloat: ((float) MAX_THUMB_DIM) /
((float)MAX(_processedWidth, _processedHeight))];
[scaleFilter setValue: scaleFactor forKey: #"inputScale"];
[scaleFilter setValue: #1.0 forKey: #"inputAspectRatio"];
CIImage *scaledImage = [scaleFilter valueForKey: #"outputImage"];
NSMutableData* thumbJpegData = [[NSMutableData alloc] init];
CGImageDestinationRef dest = CGImageDestinationCreateWithData((__bridge CFMutableDataRef)thumbJpegData,
(__bridge CFStringRef)#"public.jpeg",
1,
NULL);
if (dest)
{
CGImageRef img = [ciContext createCGImage:scaledImage
fromRect:[scaledImage extent]];
CGImageDestinationAddImage(dest, img, nil);
if (CGImageDestinationFinalize(dest))
{
// encode it as a string for later
_thumbnail = [thumbJpegData base64EncodedStringWithOptions: 0];
}
else
{
DDLogError(#"Failed to generate photo thumbnail");
}
CGImageRelease(img);
CFRelease(dest);
}
else
{
DDLogError(#"Failed to finalize photo thumbnail image");
}
thumbJpegData = nil;
}
}
CGContextRelease(bitmapContext);
CGColorSpaceRelease(colorspace);
ciContext = nil;
}
UPDATE: I switched the code to use a CGAffineTransform instead of the filter with "CILanczosScaleTransform" and the symptom did not change. Next I used a completely new method (snippet below) and yet the problem persists.
NSImage *thumbnail = [[NSImage alloc] initWithSize: newSize];
[thumbnail lockFocus];
[sourceImage setSize: newSize];
[[NSGraphicsContext currentContext] setImageInterpolation:NSImageInterpolationHigh];
[sourceImage compositeToPoint: NSZeroPoint operation: NSCompositeCopy];
[thumbnail unlockFocus];
NSData *tiff = [thumbnail TIFFRepresentation];
NSBitmapImageRep *imageRep = [NSBitmapImageRep imageRepWithData: tiff];
NSDictionary *imageProps = [NSDictionary dictionaryWithObject:[NSNumber numberWithFloat:0.9] forKey:NSImageCompressionFactor];
NSData *thumbJpegData = [imageRep representationUsingType:NSJPEGFileType properties:imageProps];
This is making me think the problem is perhaps related to something inherent in the way I'm doing this. I find it hard to believe two different methods of image scaling are going to exhibit the same sort of leak.
Thanks to this answer I was able to identify the need for an autorelease pool, something I was completely unaware of. The code in the question is one of a series of methods that are called repeatedly from inside a tight loop. This apparently prevents the OS from having a chance to do some cleanup. The block now looks like this:
#autoreleasepool {
[self findRelevantAdjustments];
[self adjustForStraightenCrop];
[self moveFacesRelativeToTopLeftOrigin];
[self createPhotoThumbnail];
[self sendPhotoToServer];
}
Moral of the story: even with ARC there are more things to pay attention to when it comes to the memory lifecycle.
The problem is not in the CGImageDestinationRef logic, because it still leaks even if you replace that with something far simple, such as:
NSBitmapImageRep *rep = [[NSBitmapImageRep alloc] initWithCIImage:scaledImage];
NSData *data = [rep representationUsingType:NSJPEGFileType properties:nil];
Digging a little further, it would appear that the problem appears to be an issue within CILanczosScaleTransform. If you use an inputScale of #1.0, then the leak disappears. But use something less than #1.0 (even #0.5) and it leaks.
I'd suggest you consider finding a different method for resizing the image.
I'm facing a weird issue, I'm drawing inside an NSImage using the following pseudo-code:
NSString* text = #"Hello world!";
NSDictionary *dict = [[[NSDictionary alloc] initWithObjectsAndKeys:[NSColor colorWithCGColor:textColor],NSForegroundColorAttributeName,font, NSFontAttributeName,nil] autorelease];
NSMutableAttributedString* str = [[[NSMutableAttributedString alloc] initWithString:text attributes:dict] autorelease];
NSSize stringSize = [str size];
NSImage* image = [[[NSImage alloc] initWithSize:stringSize] autorelease];
[image lockFocus];
NSRect drawRect = NSMakeRect(0,0,stringSize.width,stringSize.height);
[str drawInRect:drawRect];
[image unlockFocus];
Now the problem is that, with a dual monitor configuration, if I keep my retina display open, the string is mangled (I get half of the string drawn), while by simply closing my retina display and using only my cinema display, the string is drawn correctly. It's like the NSImage is getting the default context and some scaling factor from the retina display.
Do you have any hints ?
Thanks !
Ok, I will keep this for future reference, even there's something about displaying NSImage that covers the same aspect.
No matter what's your primary display but seems that the NSGraphicContext comes with an affine transformation that multiplies x 2 to address the retina resolution.
You just need to reset the affine transformations, before drawing into NSImage with:
NSAffineTransform *trans = [[[NSAffineTransform alloc] init] autorelease];
[trans set];
I am cutting up a large image and saving it into many different images. I first implemented this in iOS and it is working fine, but when I try and port the code to OSX, a thin white line (1 pixel) appears on the top and right of the image. The line is not pure white, or solid (see sample below).
Here is the iOS code to make one sub-image, that works like a champ:
-(void)testMethod:(int)page forRect:(CGRect)rect{
NSString *filePath = #"imageName";
NSData *data = [HeavyResourceManager dataForPath:filePath];//this just gets the image as NSData
UIImage *image = [UIImage imageWithData:data];
CGImageRef imageRef = CGImageCreateWithImageInRect([image CGImage], rect);//crop in the rect
UIImage *result = [UIImage imageWithCGImage:imageRef scale:0 orientation:image.imageOrientation];
CGImageRelease(imageRef);
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentsDirectoryPath = [paths objectAtIndex:0];
[UIImageJPEGRepresentation(result, 1.0) writeToFile:[documentsDirectoryPath stringByAppendingPathComponent::#"output.jpg"] atomically:YES];
}
Here is the ported code in OSX that causes the white lines to be added:
NSImage *source = [[[NSImage alloc]initWithContentsOfFile:imagePath] autorelease];
//init the image
NSImage *target = [[[NSImage alloc]initWithSize:panelRect.size] autorelease];
//start drawing
[target lockFocus];
[source drawInRect:NSMakeRect(0,0,panelRect.size.width,panelRect.size.height)
fromRect:NSMakeRect(panelRect.origin.x , source.size.height - panelRect.origin.y - panelRect.size.height, panelRect.size.width, panelRect.size.height)
operation:NSCompositeCopy
fraction:1.0];
[target unlockFocus];
//create a NSBitmapImageRep
NSBitmapImageRep *bmpImageRep = [[[NSBitmapImageRep alloc]initWithData:[target TIFFRepresentation]] autorelease];
//write to tiff
[[target TIFFRepresentation] writeToFile:#"outputImage.tiff" atomically:NO];
[target addRepresentation:bmpImageRep];
NSDictionary *imageProps = [NSDictionary dictionaryWithObject:[NSNumber numberWithFloat:1.0] forKey:NSImageCompressionFactor];
//get the data from the representation
NSData *data = [bmpImageRep representationUsingType: NSJPEGFileType
properties: imageProps];
//write the data to a file
[data writeToFile: #"outputImage.jpg" atomically:NO];
data = [bmpImageRep representationUsingType: NSPNGFileType properties: imageProps];
//write the data to png
[data writeToFile: #"outputImage.png" atomically:NO];
The above code saves the image to three different formats to check if the problem was not in the save process of a specific format. It does not seem to be because all the formats have the same problem.
Here is a blown up (4x) version of top right hand corner of the images:
(OSX, note the white line top and left. It looks like a blur here, because the image is blown up)
(iOS, note there are no white lines)
If someone could tell me why this might be happening, I would be very happy. Perhaps it has something to do with the quality difference (the OSX version seems lower quality - though you can't notice)? Perhaps there is a completely different way to do this?
For reference, here is the unscaled osx image:
Update: Thanks to Daij-Djan, I was able to stop the drawInRect method from antialiasing:
//start drawing on target
[target lockFocus];
[NSGraphicsContext saveGraphicsState];
[[NSGraphicsContext currentContext]
setImageInterpolation:NSImageInterpolationNone];
[[NSGraphicsContext currentContext] setShouldAntialias:NO];
//draw the portion of the source image on target image
[source drawInRect:NSMakeRect(0,0,panelRect.size.width,panelRect.size.height)
fromRect:NSMakeRect(panelRect.origin.x , source.size.height - panelRect.origin.y - panelRect.size.height, panelRect.size.width, panelRect.size.height)
operation:NSCompositeDestinationAtop
fraction:1.0];
[NSGraphicsContext restoreGraphicsState];
//end drawing
[target unlockFocus];
Update: Changed 'Interpolation' to NSImageInterpolationNone, as this gives a better representation. The high interpolation makes minor adjustments, which is noticeable when zooming in on text. Removing interpolation stops pixels from jumping around, but still, there is a little difference in the color (164 to 155 for a grey color). Would be great to be able to just cut up an image like I can in iOS...
it looks like antialiasing... you gotta round the float values you calculate when cutting/scaling the image.
use froundf() on the float values
I'm experiencing some massive memory leaks that don't show up using the "leaks" instrument. I pop up a Modal View Controller and apply 2 CoreImage filters to 4 or 5 different images. Using Instruments I can see the memory jump up about 40-50 MB as these images are created, but even after I dismiss the Modal View Controller, I never get that memory back, and the application will crash after repeating this process 2 or 3 times. I'm happy for any advice you can provide because this is driving me absolutely crazy. Below is the method in question:
UIView *finalView = [[UIView alloc] initWithFrame:CGRectMake(1024, 0, 1792, 1345)];
UIImageView *templateImageView = [[UIImageView alloc] initWithFrame:CGRectMake(0, 0, 1792, 1345)];
templateImageView.image = [UIImage imageNamed:[NSString stringWithFormat:#"%#.png",[theme objectForKey:#"template_background"]]];
//CI background Setup
NSString *filePath5 = [[NSBundle mainBundle] pathForResource:[theme objectForKey:#"template_background"] ofType:#"png"];
NSURL *fileNameAndPath5 = [NSURL fileURLWithPath:filePath5];
#autoreleasepool {
finalBackBeginImage = [CIImage imageWithContentsOfURL:fileNameAndPath5];
finalBackImage = [CIFilter filterWithName:#"CIHueAdjust" keysAndValues:#"inputAngle", [NSNumber numberWithFloat:[[boothPrefs objectForKey:#"templateBackground_hue"] floatValue]*6.28], #"inputImage", finalBackBeginImage, nil].outputImage;
finalBackImage = [CIFilter filterWithName:#"CIColorControls" keysAndValues:#"inputSaturation", [NSNumber numberWithFloat:([[boothPrefs objectForKey:#"templateBackground_saturation"] floatValue] * 5)], #"inputImage", finalBackImage, nil].outputImage;
finalBackContent = [CIContext contextWithOptions:nil];
CGImageRef cgimgFinalBack =
[finalBackContent createCGImage:finalBackImage fromRect:[finalBackImage extent]];
UIImage *newFinalBackImg = [UIImage imageWithCGImage:cgimgFinalBack];
[templateImageView setImage:newFinalBackImg];
CGImageRelease(cgimgFinalBack);
}
[finalView addSubview:templateImageView];
I've switched from using imageNamed to using imageWithData using the code below. In 5 minutes of testing (sorry, spent close to 12 hours on this issue now), I see that my real memory usage for the same operation is up to 50% lower (115mb versus up to 230 mb) and the mysterious "Push +80mb, pop -30mb" real memory issue appears to be solved.
I'm keeping my fingers crossed though.
//use images like this as base images for CIFilters
NSData* imageData = [NSData dataWithContentsOfFile:[[NSBundle mainBundle] pathForResource:self.frameName ofType:nil]];
;
UIImage* imageForFilter =[UIImage imageWithData: imageData];
fairly new to Objective-C and iOS development (coming from PHP) and I have a relatively simple question that I can't seem to find an answer to:
I am following along with an example for split View design where a web page is loaded into the Detail View when a user clicks an item in the master view. I got all this working, but would like to substitute web view for an image. So I've amended the app to load a UIImage instead of a WebView. What I'm looking for is the equivalent to this code:
NSString *urlString = [pagesAddress objectAtIndex:indexPath.row];
NSURL *url = [NSURL URLWithString:urlString];
// these 2 is where I get lost with the images.
NSURLRequest = *request = [NSURLRequest requestWithURL:url];
[detailViewController.webView loadRequest:request];
I came up with this:
NSString *imageName = [pagesAddress objectAtIndex:indexPath.row];
UIImage *myImage = [UIImage imageNamed:imageName];
// missing the last 2 calls: one to tell Xcode that it's an image "request" I want and the second to load the actual image (based on it's name that is already in an array) into the ImageView.
Thanks.
PS
I tried this:
NSString *imageName = [pagesAddress objectAtIndex:indexPath .row];
[detailViewController.imageView setImage:[UIImage imageNamed:imageName]];
And it shows just the first image, then crashes when I try to show the last one.
In the end, the solution were those 2 lines when I amended the code:
NSString *imageName = [pagesAddress objectAtIndex:indexPath.row];
[detailViewController.imageView setImage:[UIImage imageNamed:imageName]];
Notice that I had to change the setImage to convert the NSString to a UIImage or Xcode would complain. It turns out it was crashing because in the array where I had the image names, I had put 3 images into one entry (basically I forgot the commas!) so it was out of range.
Tim:
This line you gave me
UIImageView *imageView = [[UIImageView alloc] initWithFrame:self.view.bounds];
is unnecessary because I already have a view created, it would create another view which I never used. Also, replacing it with CGRect seems overkill if I already have a UIImage placeholder no?
In any case, it works now and I'm very grateful for all the help. iPad development with Objectve-C is a very thorny road and I expect I'll be bugging you guys some more.
Cheers.
Try this:
UIImage *myImage = [[UIImage alloc] initWithData:[NSData dataWithConentsOfURL:[NSURL URLWithString:urlString];
// don't know if you already got the following?
UIImageView *imageView = [[UIImageView alloc] initWithFrame:self.view.bounds];
[imageView setImage:myImage];
[self.view addSubview:imageView];
The first line is synchronous (= blocking), so in production, you should rather use - [NSURLRequest start] for this (but that's a bit more complicated).
Or use this for your local images:
UIImage *myImage = [UIImage imageNamed:imageName];
// Now, follow the same steps as in the first code-example, just skip the first line.
Try this (on iOS 4.0 and later):
// Execute a block of code on a background thread.
dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0),
^(void)
{
NSAutoreleasePool* pool = [[NSAutoreleasePool alloc] init];
UIImage* image = [UIImage imageWithData:[NSData dataWithContentsOfURL:url]];
// When IO is done and image created, set it on the main thread.
dispatch_async(dispatch_get_main_queue(),
^(void)
{
imageView.image = image;
});
[pool release];
});