CoreText memory leak from CTFramesetterCreateWithA

问题:

I'm coming across a problematic leak which - thanks to Instruments - appears to be coming from CTFrameSetterCreateWithAttributedString. The call stack is below.

1 CoreText -[_CTNativeGlyphStorage prepareWithCapacity:preallocated:]
2 CoreText -[_CTNativeGlyphStorage initWithCount:]
3 CoreText +[_CTNativeGlyphStorage newWithCount:]
4 CoreText TTypesetterAttrString::Initialize(__CFAttributedString const*)
5 CoreText TTypesetterAttrString::TTypesetterAttrString(__CFAttributedString const*)
6 CoreText TFramesetterAttrString::TFramesetterAttrString(__CFAttributedString const*)
7 CoreText CTFramesetterCreateWithAttributedString

The code generating this call stack is:

CFAttributedStringRef attrRef = (CFAttributedStringRef)self.attributedString;
CTFramesetterRef framesetter = CTFramesetterCreateWithAttributedString(attrRef);
CFRelease(attrRef);
...
CFRelease(framesetter);

self.attributedString gets released elsewhere. I feel like I'm correctly releasing everything else... Given all this, where could the leak be coming from? It's fairly significant for my purposes - 6-10 MB a pop. Thanks for any help.

回答1:

Turns out this problem was substantially addressed by not using an ivar for a CFMutableArrayRef. We were using the Akosma Obj-C wrapper for CoreText, and in the AKOMultiColumnTextView class there's a CFMutableArrayRef _frames ivar which - for some reason - is hanging around even after CFRelease calls. Not having the _frames ivar is a bit expensive, but has drastically improved memory usage. Thanks Neevek for your contributions.