内存泄漏,但cContextRelease会破坏视图

我面临一个记忆问题:

使用一个自定义的background.m类,我将根据传递给类的颜色选择创建渐变背景。问题出现在,似乎有泄漏,没有什么令人兴奋的,但随着时间的推移积累。释放drawrect中的上下文会消除内存问题,但不会绘制渐变。最佳解决方案/解决方案是什么?使用苹果的渐变?下面是传递给background类的drawrect方法的代码:

    //1. create vars
    float increment = 1.0f / (colours.count-1);
    CGFloat * locations = (CGFloat *)malloc((int)colours.count*sizeof(CGFloat));
    CFMutableArrayRef mref = CFArrayCreateMutable(kCFAllocatorDefault, 0, &kCFTypeArrayCallBacks);

    //2. go through the colours, creating cgColors and locations
    for (int n = 0; n < colours.count; n++){
        CFArrayAppendValue(mref, (id)[colours[n] CGColor]);
        locations[n]=(n*increment);
    }

    //3. create gradient
    CGContextRef ref = UIGraphicsGetCurrentContext();
    CGColorSpaceRef spaceRef = CGColorSpaceCreateDeviceRGB();
    CGGradientRef gradientRef = CGGradientCreateWithColors(spaceRef, mref, locations);

    if (isHorizontal){
        CGContextDrawLinearGradient(ref, gradientRef, CGPointMake(0.0, 0.0), CGPointMake(self.frame.size.width, 0.0), kCGGradientDrawsAfterEndLocation);
    } else if (isDiagonal) {
        CGContextDrawLinearGradient(ref, gradientRef, CGPointMake(0.0, 0.0), CGPointMake(self.frame.size.width, self.frame.size.height), kCGGradientDrawsAfterEndLocation);
    } else {
        CGContextDrawLinearGradient(ref, gradientRef, CGPointMake(0.0, 0.0), CGPointMake(0.0, self.frame.size.height), kCGGradientDrawsAfterEndLocation);
    }

    CGContextRelease(ref); //ISSUE
    CGColorSpaceRelease(spaceRef);
    CGGradientRelease(gradientRef);