Core Text Memory allocation issue

问题

I inspected my app with the allocation instrument and I discovered that this code down here cause me an allocation issue. The method returns the suggested height of a squared area filled with the passed attributed string; I need this in order to calculate how much space I need to draw that text and then generating book pages:

- (CGFloat)boundingHeightForWidth:(CGFloat)inWidth ForAttributedString:(NSAttributedString *)attributedString
{
     CTFramesetterRef framesetter = CTFramesetterCreateWithAttributedString((__bridge CFMutableAttributedStringRef)attributedString);
     CGSize suggestedSize = CTFramesetterSuggestFrameSizeWithConstraints(framesetter, CFRangeMake(0, 0), NULL, CGSizeMake(inWidth, 10000), NULL);
     CFRelease(framesetter);
     return suggestedSize.height ;
}

Since I am calling this method many and many times during the flow, I am wondering how this is causing up to 7MB of memory allocation.. I thought releasing the frame setter could be enough, am I wrong?

回答1:

I did some detailed debugging WRT to this issue, you can find the results in my answer to this question. There are a couple of things you could try. 1, does you app do these allocations in a secondary thread, if yes then does moving them to the main thread make the lost memory go away? Two, you could hold on to the CTFramesetterRef and then invoke CTFramesetterSuggestFrameSizeWithConstraints over and over with the same framesetter. The leak appears to be in the CTFramesetterCreateWithAttributedString() call, so perhaps you could minimize the leak by not invoking that method so many times.

来源：https://stackoverflow.com/questions/16597378/core-text-memory-allocation-issue

标签

iphone

ios

objective-c

memory

core-text