Rendering layer in background thread

gistfile1.txt

        let selfWidth = Int(width)
        let selfHeight = Int(height)
        let selfSize = CGSize(width: selfWidth, height: selfHeight)
        let title = advertisementTitle
        
        SearchPageAdvertisementView.renderQueue.async {
        
            let asyncLayer = SearchPageAdvertisementLayer()
            asyncLayer.title = title
            asyncLayer.drawsAsynchronously = true
            asyncLayer.frame = CGRect(origin: .zero, size: CGSize(width: selfWidth, height: selfHeight))
            UIGraphicsBeginImageContextWithOptions(selfSize, true, 0)
            if let context = UIGraphicsGetCurrentContext() {
                
                asyncLayer.render(in: context)
                let layerImage = UIGraphicsGetImageFromCurrentImageContext()
                
                if let cgImage = layerImage?.cgImage {

                    DispatchQueue.main.async { [weak self] in
                        self?.layer.contents = cgImage
                    }
                }
            }
            UIGraphicsEndImageContext()
        }