url.c

    }
    else {
      Curl_pgrsTime(data, TIMER_CONNECT); /* we're connected already */
      conn->bits.tcpconnect = TRUE;
      *protocol_done = TRUE;
      if(data->set.verbose)
        verboseconnect(conn);
    }
    /* Stop the loop now */
    break;
  }

  conn->now = Curl_tvnow(); /* time this *after* the connect is done, we
                               set this here perhaps a second time */

#ifdef __EMX__
  /* 20000330 mgs
   * the check is quite a hack...
   * we're calling _fsetmode to fix the problem with fwrite converting newline
   * characters (you get mangled text files, and corrupted binary files when
   * you download to stdout and redirect it to a file). */

  if ((data->set.out)->_handle == NULL) {
    _fsetmode(stdout, "b");
  }
#endif

  return CURLE_OK;
}

CURLcode Curl_connect(struct SessionHandle *data,
                      struct connectdata **in_connect,
                      bool *asyncp,
                      bool *protocol_done)
{
  CURLcode code;
  struct Curl_dns_entry *dns;

  *asyncp = FALSE; /* assume synchronous resolves by default */

  /* call the stuff that needs to be called */
  code = CreateConnection(data, in_connect, &dns, asyncp);

  if(CURLE_OK == code) {
    /* no error */
    if(dns || !*asyncp)
      /* If an address is available it means that we already have the name
         resolved, OR it isn't async. if this is a re-used connection 'dns'
         will be NULL here. Continue connecting from here */
      code = SetupConnection(*in_connect, dns, protocol_done);
    /* else
       response will be received and treated async wise */
  }

  if(CURLE_OK != code) {
    /* We're not allowed to return failure with memory left allocated
       in the connectdata struct, free those here */
    if(*in_connect) {
      Curl_disconnect(*in_connect); /* close the connection */
      *in_connect = NULL;           /* return a NULL */
    }
  }
  else {
    if ((*in_connect)->is_in_pipeline)
      data->state.is_in_pipeline = TRUE;
  }

  return code;
}

/* Call this function after Curl_connect() has returned async=TRUE and
   then a successful name resolve has been received.

   Note: this function disconnects and frees the conn data in case of
   resolve failure */
CURLcode Curl_async_resolved(struct connectdata *conn,
                             bool *protocol_done)
{
#if defined(USE_ARES) || defined(USE_THREADING_GETHOSTBYNAME) || \
    defined(USE_THREADING_GETADDRINFO)
  CURLcode code = SetupConnection(conn, conn->async.dns, protocol_done);

  if(code)
    /* We're not allowed to return failure with memory left allocated
       in the connectdata struct, free those here */
    Curl_disconnect(conn); /* close the connection */

  return code;
#else
  (void)conn;
  (void)protocol_done;
  return CURLE_OK;
#endif
}


CURLcode Curl_done(struct connectdata **connp,
                   CURLcode status) /* an error if this is called after an
                                       error was detected */
{
  CURLcode result;
  struct connectdata *conn = *connp;
  struct SessionHandle *data = conn->data;

  Curl_expire(data, 0); /* stop timer */

  if(conn->bits.done)
    return CURLE_OK; /* Curl_done() has already been called */

  conn->bits.done = TRUE; /* called just now! */

  if(Curl_removeHandleFromPipeline(data, conn->recv_pipe) &&
     conn->readchannel_inuse)
    conn->readchannel_inuse = FALSE;
  if(Curl_removeHandleFromPipeline(data, conn->send_pipe) &&
     conn->writechannel_inuse)
    conn->writechannel_inuse = FALSE;

  /* cleanups done even if the connection is re-used */
  if(data->reqdata.rangestringalloc) {
    free(data->reqdata.range);
    data->reqdata.rangestringalloc = FALSE;
  }

  /* Cleanup possible redirect junk */
  if(data->reqdata.newurl) {
    free(data->reqdata.newurl);
    data->reqdata.newurl = NULL;
  }

  if(conn->dns_entry) {
    Curl_resolv_unlock(data, conn->dns_entry); /* done with this */
    conn->dns_entry = NULL;
  }

  /* this calls the protocol-specific function pointer previously set */
  if(conn->curl_done)
    result = conn->curl_done(conn, status);
  else
    result = CURLE_OK;

  Curl_pgrsDone(conn); /* done with the operation */

  /* for ares-using, make sure all possible outstanding requests are properly
     cancelled before we proceed */
  ares_cancel(data->state.areschannel);

  /* if data->set.reuse_forbid is TRUE, it means the libcurl client has
     forced us to close this no matter what we think.

     if conn->bits.close is TRUE, it means that the connection should be
     closed in spite of all our efforts to be nice, due to protocol
     restrictions in our or the server's end */
  if(data->set.reuse_forbid || conn->bits.close) {
    CURLcode res2 = Curl_disconnect(conn); /* close the connection */

    *connp = NULL; /* to make the caller of this function better detect that
                      this was actually killed here */

    /* If we had an error already, make sure we return that one. But
       if we got a new error, return that. */
    if(!result && res2)
      result = res2;
  }
  else {
    ConnectionDone(conn); /* the connection is no longer in use */

    /* remember the most recently used connection */
    data->state.lastconnect = conn->connectindex;

    infof(data, "Connection #%ld to host %s left intact\n",
          conn->connectindex,
          conn->bits.httpproxy?conn->proxy.dispname:conn->host.dispname);
  }

  return result;
}

CURLcode Curl_do(struct connectdata **connp, bool *done)
{
  CURLcode result=CURLE_OK;
  struct connectdata *conn = *connp;
  struct SessionHandle *data = conn->data;

  conn->bits.done = FALSE; /* Curl_done() is not called yet */
  conn->bits.do_more = FALSE; /* by default there's no curl_do_more() to use */

  if(conn->curl_do) {
    /* generic protocol-specific function pointer set in curl_connect() */
    result = conn->curl_do(conn, done);

    /* This was formerly done in transfer.c, but we better do it here */

    if((CURLE_SEND_ERROR == result) && conn->bits.reuse) {
      /* This was a re-use of a connection and we got a write error in the
       * DO-phase. Then we DISCONNECT this connection and have another attempt
       * to CONNECT and then DO again! The retry cannot possibly find another
       * connection to re-use, since we only keep one possible connection for
       * each.  */

      infof(data, "Re-used connection seems dead, get a new one\n");

      conn->bits.close = TRUE; /* enforce close of this connection */
      result = Curl_done(&conn, result); /* we are so done with this */

      /* conn may no longer be a good pointer */

      /*
       * According to bug report #1330310. We need to check for
       * CURLE_SEND_ERROR here as well. I figure this could happen when the
       * request failed on a FTP connection and thus Curl_done() itself tried
       * to use the connection (again). Slight Lack of feedback in the report,
       * but I don't think this extra check can do much harm.
       */
      if((CURLE_OK == result) || (CURLE_SEND_ERROR == result)) {
        bool async;
        bool protocol_done = TRUE;

        /* Now, redo the connect and get a new connection */
        result = Curl_connect(data, connp, &async, &protocol_done);
        if(CURLE_OK == result) {
          /* We have connected or sent away a name resolve query fine */

          conn = *connp; /* setup conn to again point to something nice */
          if(async) {
            /* Now, if async is TRUE here, we need to wait for the name
               to resolve */
            result = Curl_wait_for_resolv(conn, NULL);
            if(result)
              return result;

            /* Resolved, continue with the connection */
            result = Curl_async_resolved(conn, &protocol_done);
            if(result)
              return result;
          }

          /* ... finally back to actually retry the DO phase */
          result = conn->curl_do(conn, done);
        }
      }
    }
  }
  return result;
}

CURLcode Curl_do_more(struct connectdata *conn)
{
  CURLcode result=CURLE_OK;

  if(conn->curl_do_more)
    result = conn->curl_do_more(conn);

  return result;
}