iPhone 开发:被释放的指针未分配 [英] iPhone development: pointer being freed was not allocated

问题描述

我从调试器收到了这条消息:

i got this message from the debugger:

Pixture(1257,0xa0610500) malloc: *** error for object 0x21a8000: pointer being freed was not allocated
*** set a breakpoint in malloc_error_break to debug

所以我做了一些追踪并得到:

so i did a bit of tracing and got:

(gdb) shell malloc_history 1257 0x21a8000

ALLOC 0x2196a00-0x21a89ff [size=73728]: thread_a0610500 |start |主要 |UIApplicationMain |GSEventRun |GSEventRunModal |CFRunLoopRunInMode |CFRunLoopRunSpecific |__CFRunLoopDoObservers |CA::Transaction::observer_callback(__CFRunLoopObserver*, unsigned long, void*) |CA::事务::提交() |CA::Context::commit_transaction(CA::Transaction*) |CALayerDisplayIfNeeded |-[CALayer_display] |CABackingStoreUpdate |backing_callback(CGContext*, void*) |-[CALayer drawInContext:] |-[UIView(CALayerDelegate) drawLayer:inContext:] |-[AvatarView drawRect:] |-[AvatarView overlayPNG:] |+[UIImageUtility createMaskOf:] |UIGraphicsGetImageFromCurrentImageContext |CGBitmapContextCreateImage |create_bitmap_data_provider |malloc |malloc_zone_malloc

我真的不明白我做错了什么.这是 [UIImageUtility createMaskOf:] 函数的代码:

and i really can't understand what i am doing wrong. here's the code of the [UIImageUtility createMaskOf:] function:

+ (UIImage *)createMaskOf:(UIImage *)source {
    CGRect rect = CGRectMake(0, 0, source.size.width, source.size.height);
    UIGraphicsBeginImageContext(CGSizeMake(source.size.width, source.size.height));
    CGContextRef context = UIGraphicsGetCurrentContext();

    CGContextTranslateCTM(context, 0, source.size.height);
    CGContextScaleCTM(context, 1.0, -1.0);

    UIImage *original = [self createGrayCopy:source];

    CGContextRef context2 = CGBitmapContextCreate(NULL, source.size.width, source.size.height, 8, 4 * source.size.width, 
                                                   CGColorSpaceCreateDeviceRGB(), kCGImageAlphaNoneSkipLast);
    CGContextDrawImage(context2, CGRectMake(0, 0, source.size.width, source.size.height), original.CGImage);
    CGImageRef unmasked = CGBitmapContextCreateImage(context2);

    const float myMaskingColorsFrameColor[6] = { 1,256,1,256,1,256 };
    CGImageRef mask = CGImageCreateWithMaskingColors(unmasked, myMaskingColorsFrameColor);

    CGContextSetRGBFillColor (context, 256,256,256, 1);
    CGContextFillRect(context, rect);
    CGContextDrawImage(context, rect, mask);

    UIImage *whiteMasked = UIGraphicsGetImageFromCurrentImageContext();

    UIGraphicsEndImageContext();

    return whiteMasked;
}

之前调用的另一个自定义函数如下:

the other custom function called before that is the following:

- (UIImage *)overlayPNG:(SinglePart *)sp {
    NSLog([sp description]);
    // Rect and context setup
    CGRect rect = CGRectMake(0, 0, sp.image.size.width, sp.image.size.height);
    NSLog(@"%f x %f", sp.image.size.width, sp.image.size.height);

    // Create an image of a color filled rectangle
    UIImage *baseColor = nil;
    if (sp.hasOwnColor) {
            baseColor = [UIImageUtility imageWithRect:rect ofColor:sp.color];
    } else {
        SinglePart *facePart = [editingAvatar.face.partList objectAtIndex:0];
        baseColor = [UIImageUtility imageWithRect:rect ofColor:facePart.color];
    }

    // Crete the mask of the layer
    UIImage *mask = [UIImageUtility createMaskOf:sp.image];
    mask = [UIImageUtility createGrayCopy:mask];

    // Create a new context for merging the overlay and a mask of the layer
    UIGraphicsBeginImageContext(CGSizeMake(sp.image.size.width, sp.image.size.height));
    CGContextRef context2 = UIGraphicsGetCurrentContext(); 

    // Adjust the coordinate system so that the origin 
    // is in the lower left corner of the view and the 
    // y axis points up 
    CGContextTranslateCTM(context2, 0, sp.image.size.height); 
    CGContextScaleCTM(context2, 1.0, -1.0); 

    // Create masked overlay color layer
    CGImageRef MaskedImage = CGImageCreateWithMask (baseColor.CGImage, mask.CGImage);

    // Draw the base color layer
    CGContextDrawImage(context2, rect, MaskedImage);

    // Get the result of the masking
    UIImage* overlayMasked = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();

    UIGraphicsBeginImageContext(CGSizeMake(sp.image.size.width, sp.image.size.height));
    CGContextRef context = UIGraphicsGetCurrentContext();

    // Adjust the coordinate system so that the origin 
    // is in the lower left corner of the view and the 
    // y axis points up 
    CGContextTranslateCTM(context, 0, sp.image.size.height);
    CGContextScaleCTM(context, 1.0, -1.0);

    // Get the result of the blending of the masked overlay and the base image
    CGContextDrawImage(context, rect, overlayMasked.CGImage);

    // Set the blend mode for the next drawn image
    CGContextSetBlendMode(context, kCGBlendModeOverlay);

    // Component image drawn
    CGContextDrawImage(context, rect, sp.image.CGImage);

    UIImage* blendedImage = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();

    CGImageRelease(MaskedImage);

    return blendedImage;
}

推荐答案

我遇到了同样的问题，有很多相同的症状:

I've had the same problem, with a lot of the same symptoms:

• 被释放的指针未分配错误
• 升级到 Xcode 3.2
• 图像代码中发生错误

如果我将构建目标更改为 3.1，模拟器中的错误就会消失.如果我在设备上运行代码，则不会出现错误.可能是 3.0 中的一个错误

If I change the build target to 3.1, the errors in the simulator go away. If I run the code on the device, the errors don't appear. Possibly a bug in 3.0

我的建议是将 3.1 作为您的目标进行测试，如果您愿意，您可以针对 3.0 进行构建以进行发布，而不必担心错误，因为它们不会发生在设备上.

My advice is to test with 3.1 as your target, and if you want, you can build for 3.0 for release and not worry about the errors as they don't happen on the device.

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