CODEWITHSUNDEEP
iphonecocoa-touchmemory-managementquartz-graphics
willc2
willc2

Reputation: 39701

How do I release this CGPath when I need to return it

I have a method that returns a CGMutablePathRef, something like this:

- (CGMutablePathRef)somePath;  
{  
    CGMutablePathRef theLine = CGPathCreateMutable(); 

    CGPathMoveToPoint(theLine, NULL, 50, 50);  
    CGPathAddLineToPoint(theLine, NULL, 160, 480);  
    CGPathAddLineToPoint(theLine, NULL, 270, 50);

    return theLine;  
}

The Xcode/Clang static analyzer warns that there's a potential leak. The docs say to call CGPathRelease() but where would I put that?

If I put that before the method returns won't that cause theLine to disappear before it's returned to it's caller?

Upvotes: 27

Views: 7792

Answers (2)

benzado
benzado

Reputation: 84398

If a method name begins with new, clang will expect it to return an object with a retain count of 1. In other words, renaming the method from somePath to newSomePath will quiet the Analyzer.

If you actually want to autorelease the CGPathRef, you might be able to cast it to an NSObject and then call autorelease. I know that works for CFTypes, I'm honestly not sure if CGPathRef qualifies.

Upvotes: 29

Mobs
Mobs

Reputation: 1562

How about creating a mutablepath, passing it to your building function, then using and releasing it:

CGMutablePathRef mPath = CGPathCreateMutable();
[buildPath:mPath]; //adds reusable lines etc
...do something with it...
CGPathRelease(mPath);

Upvotes: 8

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