conf = new(http2Server)
	}
	conf.state = &http2serverInternalState{activeConns: make(map[*http2serverConn]struct{})}
	if h1, h2 := s, conf; h2.IdleTimeout == 0 {
		if h1.IdleTimeout != 0 {
			h2.IdleTimeout = h1.IdleTimeout
		} else {
			h2.IdleTimeout = h1.ReadTimeout
		}
	}
	s.RegisterOnShutdown(conf.state.startGracefulShutdown)

	if s.TLSConfig == nil {
		s.TLSConfig = new(tls.Config)