panic(err)
			}
		}
	}
}

func getHosts(n int) (hosts []string, listeners []net.Listener, err error) {
	for i := 0; i < n; i++ {
		l, err := net.Listen("tcp", "127.0.0.1:0")
		if err != nil {
			if l, err = net.Listen("tcp6", "[::1]:0"); err != nil {
				return nil, nil, fmt.Errorf("httptest: failed to listen on a port: %v", err)
			}
		}
		addr := l.Addr()

func (m MQTTArgs) Validate() error {
	if !m.Enable {
		return nil
	}
	u, err := xnet.ParseURL(m.Broker.String())
	if err != nil {
		return err
	}
	switch u.Scheme {
	case "ws", "wss", "tcp", "ssl", "tls", "tcps":
	default:
		return errors.New("unknown protocol in broker address")
	}
	if m.QueueDir != "" {
		if !filepath.IsAbs(m.QueueDir) {
			return errors.New("queueDir path should be absolute")
		}

				_ = syscall.SetsockoptInt(fd, syscall.IPPROTO_TCP, syscall.TCP_KEEPINTVL, 15)
			}

			// Set tcp user timeout in addition to the keep-alive - tcp-keepalive is not enough to close a socket
			// with dead end because tcp-keepalive is not fired when there is data in the socket buffer.
			//    https://blog.cloudflare.com/when-tcp-sockets-refuse-to-die/

type httpListener struct {
	opts        TCPOptions
	listeners   []net.Listener    // underlying TCP listeners.
	acceptCh    chan acceptResult // channel where all TCP listeners write accepted connection.
	ctx         context.Context
	ctxCanceler context.CancelFunc
}

// start - starts separate goroutine for each TCP listener.  A valid new connection is passed to httpListener.acceptCh.
func (listener *httpListener) start() {

* Шифрование соединения происходит **на уровне протокола TCP**.
    * Протокол TCP находится на один уровень **ниже протокола HTTP**.
    * Поэтому **проверка сертификатов и шифрование** происходит **до HTTP**.
* **TCP не знает о "доменах"**, но знает об IP-адресах.
    * Информация о **запрашиваемом домене** извлекается из запроса **на уровне HTTP**.

After this, the client and the server have an **encrypted TCP connection**, this is what TLS provides. And then they can use that connection to start the actual **HTTP communication**.

And that's what **HTTPS** is, it's just plain **HTTP** inside a **secure TLS connection** instead of a pure (unencrypted) TCP connection.

/// tip

* A criptografia da conexão acontece no nível TCP.
    * Essa é uma camada abaixo do HTTP.
    * Portanto, o manuseio do certificado e da criptografia é feito antes do HTTP.
* O TCP não sabe sobre "domínios". Apenas sobre endereços IP.
    * As informações sobre o domínio solicitado vão nos dados HTTP.
* Os certificados HTTPS “certificam” um determinado domínio, mas o protocolo e a encriptação acontecem ao nível do TCP, antes de sabermos de que domínio se trata.

	tcpTimeForFirstByteTotalDur uint64
}{}

// RPCStats holds information about the DHCP/TCP metrics and errors
type RPCStats struct {
	Errs uint64

	DialAvgDuration uint64
	TTFBAvgDuration uint64
	DialErrs        uint64
}

// GetRPCStats returns RPC stats, include calls errors and dhcp/tcp metrics
func GetRPCStats() RPCStats {
	s := RPCStats{
		Errs:     atomic.LoadUint64(&globalStats.errs),

/// tip | "Tipp"

Beachten Sie, dass die Verschlüsselung der Kommunikation auf der **TCP-Ebene** und nicht auf der HTTP-Ebene erfolgt.

///

### HTTPS-Request

Da Client und Server (sprich, der Browser und der TLS-Terminierungsproxy) nun über eine **verschlüsselte TCP-Verbindung** verfügen, können sie die **HTTP-Kommunikation** starten.

      with:
        path: ~/go/pkg/mod
        key: ${{ runner.os }}-go-${{ matrix.go }}-${{ hashFiles('tests/go.mod') }}

    - name: Tests
      run: GITHUB_ACTION=true GORM_DIALECT=mysql GORM_DSN="gorm:gorm@tcp(localhost:9910)/gorm?charset=utf8&parseTime=True" ./tests/tests_all.sh

  mariadb:
    strategy:
      matrix:
        dbversion: [ 'mariadb:latest' ]
        go: ['1.22', '1.21', '1.20']