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    }

    /* For each trip through the entire server list, double the channel's
     * assigned timeout, avoiding overflow.  If channel->timeout is negative,
     * leave it as-is, even though that should be impossible here.
     */
    timeplus = channel->timeout;
    {
      /* How many times do we want to double it?  Presume sane values here. */
      const int shift = query->try_count / channel->nservers;

      /* Is there enough room to shift timeplus left that many times?
       *
       * To find out, confirm that all of the bits we'll shift away are zero.
       * Stop considering a shift if we get to the point where we could shift
       * a 1 into the sign bit (i.e. when shift is within two of the bit
       * count).
       *
       * This has the side benefit of leaving negative numbers unchanged.
       */
      if(shift <= (int)(sizeof(int) * CHAR_BIT - 1)
         && (timeplus >> (sizeof(int) * CHAR_BIT - 1 - shift)) == 0)
      {
        timeplus <<= shift;
      }
    }

    query->timeout = *now;
    timeadd(&query->timeout, timeplus);
    /* Keep track of queries bucketed by timeout, so we can process
     * timeout events quickly.
     */
    ares__remove_from_list(&(query->queries_by_timeout));
    ares__insert_in_list(
        &(query->queries_by_timeout),
        &(channel->queries_by_timeout[query->timeout.tv_sec %
                                      ARES_TIMEOUT_TABLE_SIZE]));

    /* Keep track of queries bucketed by server, so we can process server
     * errors quickly.
     */
    ares__remove_from_list(&(query->queries_to_server));
    ares__insert_in_list(&(query->queries_to_server),
                         &(server->queries_to_server));
}

/*
 * setsocknonblock sets the given socket to either blocking or non-blocking
 * mode based on the 'nonblock' boolean argument. This function is highly
 * portable.
 */
static int setsocknonblock(ares_socket_t sockfd,    /* operate on this */
                           int nonblock   /* TRUE or FALSE */)
{
#if defined(USE_BLOCKING_SOCKETS)

  return 0; /* returns success */

#elif defined(HAVE_FCNTL_O_NONBLOCK)

  /* most recent unix versions */
  int flags;
  flags = fcntl(sockfd, F_GETFL, 0);
  if (FALSE != nonblock)
    return fcntl(sockfd, F_SETFL, flags | O_NONBLOCK);
  else
    return fcntl(sockfd, F_SETFL, flags & (~O_NONBLOCK));  /* LCOV_EXCL_LINE */

#elif defined(HAVE_IOCTL_FIONBIO)

  /* older unix versions */
  int flags = nonblock ? 1 : 0;
  return ioctl(sockfd, FIONBIO, &flags);

#elif defined(HAVE_IOCTLSOCKET_FIONBIO)

#ifdef WATT32
  char flags = nonblock ? 1 : 0;
#else
  /* Windows */
  unsigned long flags = nonblock ? 1UL : 0UL;
#endif
  return ioctlsocket(sockfd, FIONBIO, &flags);

#elif defined(HAVE_IOCTLSOCKET_CAMEL_FIONBIO)

  /* Amiga */
  long flags = nonblock ? 1L : 0L;
  return IoctlSocket(sockfd, FIONBIO, flags);

#elif defined(HAVE_SETSOCKOPT_SO_NONBLOCK)

  /* BeOS */
  long b = nonblock ? 1L : 0L;
  return setsockopt(sockfd, SOL_SOCKET, SO_NONBLOCK, &b, sizeof(b));

#else
#  error "no non-blocking method was found/used/set"
#endif
}

static int configure_socket(ares_socket_t s, int family, ares_channel channel)
{
  ares_sockaddr local;

  /* do not set options for user-managed sockets */
  if (channel->sock_funcs)
    return 0;

  (void)setsocknonblock(s, TRUE);

#if defined(FD_CLOEXEC) && !defined(MSDOS)
  /* Configure the socket fd as close-on-exec. */
  if (fcntl(s, F_SETFD, FD_CLOEXEC) == -1)
    return -1;  /* LCOV_EXCL_LINE */
#endif

  /* Set the socket's send and receive buffer sizes. */
  if ((channel->socket_send_buffer_size > 0) &&
      setsockopt(s, SOL_SOCKET, SO_SNDBUF,
                 (void *)&channel->socket_send_buffer_size,
                 sizeof(channel->socket_send_buffer_size)) == -1)
    return -1;

  if ((channel->socket_receive_buffer_size > 0) &&
      setsockopt(s, SOL_SOCKET, SO_RCVBUF,
                 (void *)&channel->socket_receive_buffer_size,
                 sizeof(channel->socket_receive_buffer_size)) == -1)
    return -1;

#ifdef SO_BINDTODEVICE