iPhone开发：没有分配被释放的指针 [英] iPhone development: pointer being freed was not allocated

问题描述

我从调试器收到此消息：

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

所以我做了一些跟踪并得到了：

so i did a bit of tracing and got:

（gdb）shell malloc_history 1257 0x21a8000

ALLOC 0x2196a00-0x21a89ff [size = 73728]：thread_a0610500 | start |主| UIApplicationMain | GSEventRun | GSEventRunModal | CFRunLoopRunInMode | CFRunLoopRunSpecific | __CFRunLoopDoObservers | CA :: Transaction :: observer_callback（__ CFRunLoopObserver *，unsigned long，void *）| CA :: Transaction :: commit（）| 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

我真的无法理解我做错了什么。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;
}

之前调用的其他自定义函数如下：

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

我有同样的问题，有很多相同的症状：

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

• 指针被释放没有分配错误


• 升级到Xcode 3.2


• 在图像代码中发生错误

如果我更改构建目标到3.1，模拟器中的错误消失了。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

我的建议是使用3.1作为目标进行测试，如果需要，可以为3.0版本进行发布而不用担心错误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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