// main ServeHTTP goroutine, this will show up rarely.
var http2errHandlerPanicked = errors.New("http2: handler panicked")

// wroteFrame is called on the serve goroutine with the result of
// whatever happened on writeFrameAsync.
func (sc *http2serverConn) wroteFrame(res http2frameWriteResult) {
	sc.serveG.check()
	if !sc.writingFrame {
		panic("internal error: expected to be already writing a frame")
	}

		frame = ws.NewFrame(op, fin, payload)
		frame = ws.MaskFrameInPlace(frame)
	} else {
		frame = ws.NewFrame(op, fin, p)
	}

	return ww.writeFrame(w, frame)
}

// writeFrame writes frame binary representation into w.
func (ww *wsWriter) writeFrame(w io.Writer, f ws.Frame) error {
	const (
		bit0  = 0x80
		len7  = int64(125)
		len16 = int64(^(uint16(0)))
		len64 = int64(^(uint64(0)) >> 1)
	)