/**
   * Determines whether {@link #runInConnectThread(DTLSProtocol, TlsPeer, DatagramTransport)} is to
   * try to establish a DTLS connection.
   *
   * @param i the number of tries remaining after the current one
   * @param datagramTransport
   * @return <tt>true</tt> to try to establish a DTLS connection; otherwise, <tt>false</tt>
   */
  private boolean enterRunInConnectThreadLoop(int i, DatagramTransport datagramTransport) {
    if (i < 0 || i > CONNECT_TRIES) {
      return false;
    } else {
      Thread currentThread = Thread.currentThread();

      synchronized (this) {
        if (i > 0 && i < CONNECT_TRIES - 1) {
          boolean interrupted = false;

          try {
            wait(CONNECT_RETRY_INTERVAL);
          } catch (InterruptedException ie) {
            interrupted = true;
          }
          if (interrupted) currentThread.interrupt();
        }

        return currentThread.equals(this.connectThread)
            && datagramTransport.equals(this.datagramTransport);
      }
    }
  }
  /**
   * Runs in {@link #connectThread} to initialize {@link #dtlsTransport}.
   *
   * @param dtlsProtocol
   * @param tlsPeer
   * @param datagramTransport
   */
  private void runInConnectThread(
      DTLSProtocol dtlsProtocol, TlsPeer tlsPeer, DatagramTransport datagramTransport) {
    DTLSTransport dtlsTransport = null;
    final boolean srtp = !transformEngine.isSrtpDisabled();
    int srtpProtectionProfile = 0;
    TlsContext tlsContext = null;

    // DTLS client
    if (dtlsProtocol instanceof DTLSClientProtocol) {
      DTLSClientProtocol dtlsClientProtocol = (DTLSClientProtocol) dtlsProtocol;
      TlsClientImpl tlsClient = (TlsClientImpl) tlsPeer;

      for (int i = CONNECT_TRIES - 1; i >= 0; i--) {
        if (!enterRunInConnectThreadLoop(i, datagramTransport)) break;
        try {
          dtlsTransport = dtlsClientProtocol.connect(tlsClient, datagramTransport);
          break;
        } catch (IOException ioe) {
          if (!handleRunInConnectThreadException(
              ioe, "Failed to connect this DTLS client to a DTLS" + " server!", i)) {
            break;
          }
        }
      }
      if (dtlsTransport != null && srtp) {
        srtpProtectionProfile = tlsClient.getChosenProtectionProfile();
        tlsContext = tlsClient.getContext();
      }
    }
    // DTLS server
    else if (dtlsProtocol instanceof DTLSServerProtocol) {
      DTLSServerProtocol dtlsServerProtocol = (DTLSServerProtocol) dtlsProtocol;
      TlsServerImpl tlsServer = (TlsServerImpl) tlsPeer;

      for (int i = CONNECT_TRIES - 1; i >= 0; i--) {
        if (!enterRunInConnectThreadLoop(i, datagramTransport)) break;
        try {
          dtlsTransport = dtlsServerProtocol.accept(tlsServer, datagramTransport);
          break;
        } catch (IOException ioe) {
          if (!handleRunInConnectThreadException(
              ioe, "Failed to accept a connection from a DTLS client!", i)) {
            break;
          }
        }
      }
      if (dtlsTransport != null && srtp) {
        srtpProtectionProfile = tlsServer.getChosenProtectionProfile();
        tlsContext = tlsServer.getContext();
      }
    } else {
      // It MUST be either a DTLS client or a DTLS server.
      throw new IllegalStateException("dtlsProtocol");
    }

    SinglePacketTransformer srtpTransformer =
        (dtlsTransport == null || !srtp)
            ? null
            : initializeSRTPTransformer(srtpProtectionProfile, tlsContext);
    boolean closeSRTPTransformer;

    synchronized (this) {
      if (Thread.currentThread().equals(this.connectThread)
          && datagramTransport.equals(this.datagramTransport)) {
        this.dtlsTransport = dtlsTransport;
        _srtpTransformer = srtpTransformer;
        notifyAll();
      }
      closeSRTPTransformer = (_srtpTransformer != srtpTransformer);
    }
    if (closeSRTPTransformer && srtpTransformer != null) srtpTransformer.close();
  }