Drawing figures on context take time

Question

I am using CGContext to draw figures on it(e.g. rectangle,ellipse,line,polygon)

code: rect = CGRectMake(10,10,10,10); mWBContext = [[NSGraphicsContext graphicsContextWithWindow:[self window]]graphicsPort]; CGContextFillRect(mWBContext,rect);

It draws the rectangle but take some time.sometimes it may be 2 mins sometimes more than that and sometimes less than that.

Plz if any one have any solution then help me out.