// Only override drawRect: if you perform custom drawing.
// An empty implementation adversely affects performance during animation.
- (void)drawRect:(CGRect)rect
{
    // Drawing code
    CGContextRef context = UIGraphicsGetCurrentContext();
    
    CGContextSetLineWidth(context, 1.0);
    CGContextSetLineCap(context, kCGLineCapRound);
    CGContextSetStrokeColorWithColor(context, [UIColor redColor].CGColor);
    CGFloat startAngle = -M_PI/3;
    CGFloat step = 11*M_PI/6 * self.progress;
    CGContextAddArc(context, self.bounds.size.width/2, self.bounds.size.height/2, self.bounds.size.width/2-3, startAngle, startAngle+step, 0);
    CGContextStrokePath(context);
}