gsocket.cpp

来自「A*算法 A*算法 A*算法 A*算法A*算法A*算法」· C++ 代码 · 共 1,932 行 · 第 1/4 页

 *  mode (blocking | nonblocking) of the socket.
 */
GSocketEventFlags GSocket::Select(GSocketEventFlags flags)
{
  if (!gs_gui_functions->CanUseEventLoop())
  {

    GSocketEventFlags result = 0;
    fd_set readfds;
    fd_set writefds;
    fd_set exceptfds;
    struct timeval tv;

    assert(this);

    if (m_fd == -1)
        return (GSOCK_LOST_FLAG & flags);
    
    /* Do not use a static struct, Linux can garble it */
    tv.tv_sec = m_timeout / 1000;
    tv.tv_usec = (m_timeout % 1000) * 1000;

    FD_ZERO(&readfds);
    FD_ZERO(&writefds);
    FD_ZERO(&exceptfds);
    FD_SET(m_fd, &readfds);
    if (flags & GSOCK_OUTPUT_FLAG || flags & GSOCK_CONNECTION_FLAG)
      FD_SET(m_fd, &writefds);
    FD_SET(m_fd, &exceptfds);

    /* Check 'sticky' CONNECTION flag first */
    result |= (GSOCK_CONNECTION_FLAG & m_detected);

    /* If we have already detected a LOST event, then don't try
     * to do any further processing.
     */
    if ((m_detected & GSOCK_LOST_FLAG) != 0)
    {
      m_establishing = false;

      return (GSOCK_LOST_FLAG & flags);
    }

    /* Try select now */
    if (select(m_fd + 1, &readfds, &writefds, &exceptfds, &tv) <= 0)
    {
      /* What to do here? */
      return (result & flags);
    }

    /* Check for exceptions and errors */
    if (FD_ISSET(m_fd, &exceptfds))
    {
      m_establishing = false;
      m_detected = GSOCK_LOST_FLAG;

      /* LOST event: Abort any further processing */
      return (GSOCK_LOST_FLAG & flags);
    }

    /* Check for readability */
    if (FD_ISSET(m_fd, &readfds))
    {
      result |= GSOCK_INPUT_FLAG;

      if (m_server && m_stream)
      {
        /* This is a TCP server socket that detected a connection.
          While the INPUT_FLAG is also set, it doesn't matter on
          this kind of  sockets, as we can only Accept() from them. */        
        result |= GSOCK_CONNECTION_FLAG;
        m_detected |= GSOCK_CONNECTION_FLAG;
      }
    }

    /* Check for writability */
    if (FD_ISSET(m_fd, &writefds))
    {
      if (m_establishing && !m_server)
      {
        int error;
        SOCKOPTLEN_T len = sizeof(error);

        m_establishing = false;

        getsockopt(m_fd, SOL_SOCKET, SO_ERROR, (char*)&error, &len);

        if (error)
        {
          m_detected = GSOCK_LOST_FLAG;

          /* LOST event: Abort any further processing */
          return (GSOCK_LOST_FLAG & flags);
        }
        else
        {
          result |= GSOCK_CONNECTION_FLAG;
          m_detected |= GSOCK_CONNECTION_FLAG;
        }
      }
      else
      {
        result |= GSOCK_OUTPUT_FLAG;
      }
    }

    return (result & flags);

  }
  else
  {

    assert(this);
    return flags & m_detected;

  }
}

/* Flags */

/* GSocket_SetNonBlocking:
 *  Sets the socket to non-blocking mode. All IO calls will return
 *  immediately.
 */
void GSocket::SetNonBlocking(bool non_block)
{
  assert(this);

  GSocket_Debug( ("GSocket_SetNonBlocking: %d\n", (int)non_block) );

  m_non_blocking = non_block;
}

/* GSocket_SetTimeout:
 *  Sets the timeout for blocking calls. Time is expressed in
 *  milliseconds.
 */
void GSocket::SetTimeout(unsigned long millisec)
{
  assert(this);

  m_timeout = millisec;
}

/* GSocket_GetError:
 *  Returns the last error occurred for this socket. Note that successful
 *  operations do not clear this back to GSOCK_NOERROR, so use it only
 *  after an error.
 */
GSocketError WXDLLIMPEXP_NET GSocket::GetError()
{
  assert(this);

  return m_error;
}

/* Callbacks */

/* GSOCK_INPUT:
 *   There is data to be read in the input buffer. If, after a read
 *   operation, there is still data available, the callback function will
 *   be called again.
 * GSOCK_OUTPUT:
 *   The socket is available for writing. That is, the next write call
 *   won't block. This event is generated only once, when the connection is
 *   first established, and then only if a call failed with GSOCK_WOULDBLOCK,
 *   when the output buffer empties again. This means that the app should
 *   assume that it can write since the first OUTPUT event, and no more
 *   OUTPUT events will be generated unless an error occurs.
 * GSOCK_CONNECTION:
 *   Connection successfully established, for client sockets, or incoming
 *   client connection, for server sockets. Wait for this event (also watch
 *   out for GSOCK_LOST) after you issue a nonblocking GSocket_Connect() call.
 * GSOCK_LOST:
 *   The connection is lost (or a connection request failed); this could
 *   be due to a failure, or due to the peer closing it gracefully.
 */

/* GSocket_SetCallback:
 *  Enables the callbacks specified by 'flags'. Note that 'flags'
 *  may be a combination of flags OR'ed toghether, so the same
 *  callback function can be made to accept different events.
 *  The callback function must have the following prototype:
 *
 *  void function(GSocket *socket, GSocketEvent event, char *cdata)
 */
void GSocket::SetCallback(GSocketEventFlags flags,
                         GSocketCallback callback, char *cdata)
{
  int count;

  assert(this);

  for (count = 0; count < GSOCK_MAX_EVENT; count++)
  {
    if ((flags & (1 << count)) != 0)
    {
      m_cbacks[count] = callback;
      m_data[count] = cdata;
    }
  }
}

/* GSocket_UnsetCallback:
 *  Disables all callbacks specified by 'flags', which may be a
 *  combination of flags OR'ed toghether.
 */
void GSocket::UnsetCallback(GSocketEventFlags flags)
{
  int count;

  assert(this);

  for (count = 0; count < GSOCK_MAX_EVENT; count++)
  {
    if ((flags & (1 << count)) != 0)
    {
      m_cbacks[count] = NULL;
      m_data[count] = NULL;
    }
  }
}

GSocketError GSocket::GetSockOpt(int level, int optname,
                                void *optval, int *optlen)
{
    if (getsockopt(m_fd, level, optname, (char*)optval, (SOCKOPTLEN_T*)optlen) == 0)
    {
        return GSOCK_NOERROR;
    }
    return GSOCK_OPTERR;
}

GSocketError GSocket::SetSockOpt(int level, int optname,
                                const void *optval, int optlen)
{
    if (setsockopt(m_fd, level, optname, (const char*)optval, optlen) == 0)
    {
        return GSOCK_NOERROR;
    }
    return GSOCK_OPTERR;
}

#define CALL_CALLBACK(socket, event) {                                  \
  socket->Disable(event);                                               \
  if (socket->m_cbacks[event])                                          \
    socket->m_cbacks[event](socket, event, socket->m_data[event]);      \
}


void GSocket::Enable(GSocketEvent event)
{
  m_detected &= ~(1 << event);
  gs_gui_functions->Install_Callback(this, event);
}

void GSocket::Disable(GSocketEvent event)
{
  m_detected |= (1 << event);
  gs_gui_functions->Uninstall_Callback(this, event);
}

/* _GSocket_Input_Timeout:
 *  For blocking sockets, wait until data is available or
 *  until timeout ellapses.
 */
GSocketError GSocket::Input_Timeout()
{
  struct timeval tv;
  fd_set readfds;
  int ret;

  /* Linux select() will overwrite the struct on return */
  tv.tv_sec  = (m_timeout / 1000);
  tv.tv_usec = (m_timeout % 1000) * 1000;

  if (!m_non_blocking)
  {
    FD_ZERO(&readfds);
    FD_SET(m_fd, &readfds);
    ret = select(m_fd + 1, &readfds, NULL, NULL, &tv);
    if (ret == 0)
    {
      GSocket_Debug(( "GSocket_Input_Timeout, select returned 0\n" ));
      m_error = GSOCK_TIMEDOUT;
      return GSOCK_TIMEDOUT;
    }
    if (ret == -1)
    {
      GSocket_Debug(( "GSocket_Input_Timeout, select returned -1\n" ));
      if (errno == EBADF) { GSocket_Debug(( "Invalid file descriptor\n" )); }
      if (errno == EINTR) { GSocket_Debug(( "A non blocked signal was caught\n" )); }
      if (errno == EINVAL) { GSocket_Debug(( "The highest number descriptor is negative\n" )); }
      if (errno == ENOMEM) { GSocket_Debug(( "Not enough memory\n" )); }
      m_error = GSOCK_TIMEDOUT;
      return GSOCK_TIMEDOUT;
    }
  }
  return GSOCK_NOERROR;
}

/* _GSocket_Output_Timeout:
 *  For blocking sockets, wait until data can be sent without
 *  blocking or until timeout ellapses.
 */
GSocketError GSocket::Output_Timeout()
{
  struct timeval tv;
  fd_set writefds;
  int ret;

  /* Linux select() will overwrite the struct on return */
  tv.tv_sec  = (m_timeout / 1000);
  tv.tv_usec = (m_timeout % 1000) * 1000;

  GSocket_Debug( ("m_non_blocking has: %d\n", (int)m_non_blocking) );

  if (!m_non_blocking)
  {
    FD_ZERO(&writefds);
    FD_SET(m_fd, &writefds);
    ret = select(m_fd + 1, NULL, &writefds, NULL, &tv);
    if (ret == 0)
    {
      GSocket_Debug(( "GSocket_Output_Timeout, select returned 0\n" ));
      m_error = GSOCK_TIMEDOUT;
      return GSOCK_TIMEDOUT;
    }
    if (ret == -1)
    {
      GSocket_Debug(( "GSocket_Output_Timeout, select returned -1\n" ));
      if (errno == EBADF) { GSocket_Debug(( "Invalid file descriptor\n" )); }
      if (errno == EINTR) { GSocket_Debug(( "A non blocked signal was caught\n" )); }
      if (errno == EINVAL) { GSocket_Debug(( "The highest number descriptor is negative\n" )); }
      if (errno == ENOMEM) { GSocket_Debug(( "Not enough memory\n" )); }
      m_error = GSOCK_TIMEDOUT;
      return GSOCK_TIMEDOUT;
    }
    if ( ! FD_ISSET(m_fd, &writefds) ) {
        GSocket_Debug(( "GSocket_Output_Timeout is buggy!\n" ));
    }
    else {
        GSocket_Debug(( "GSocket_Output_Timeout seems correct\n" ));
    }
  }
  else
  {
    GSocket_Debug(( "GSocket_Output_Timeout, didn't try select!\n" ));
  }

  return GSOCK_NOERROR;
}

int GSocket::Recv_Stream(char *buffer, int size)
{
  int ret;
  do
  {
    ret = recv(m_fd, buffer, size, GSOCKET_MSG_NOSIGNAL);
  } while (ret == -1 && errno == EINTR); /* Loop until not interrupted */
  return ret;
}

int GSocket::Recv_Dgram(char *buffer, int size)
{
  struct sockaddr from;
  WX_SOCKLEN_T fromlen = sizeof(from);
  int ret;
  GSocketError err;

  fromlen = sizeof(from);

  do
  {
    ret = recvfrom(m_fd, buffer, size, 0, &from, (WX_SOCKLEN_T *) &fromlen);
  } while (ret == -1 && errno == EINTR); /* Loop until not interrupted */

  if (ret == -1)
    return -1;

  /* Translate a system address into a GSocket address */
  if (!m_peer)
  {
    m_peer = GAddress_new();
    if (!m_peer)
    {
      m_error = GSOCK_MEMERR;
      return -1;
    }
  }
  err = _GAddress_translate_from(m_peer, &from, fromlen);
  if (err != GSOCK_NOERROR)
  {
    GAddress_destroy(m_peer);
    m_peer  = NULL;
    m_error = err;
    return -1;
  }

  return ret;
}

int GSocket::Send_Stream(const char *buffer, int size)
{
  int ret;

  MASK_SIGNAL();

  do
  {
    ret = send(m_fd, (char *)buffer, size, GSOCKET_MSG_NOSIGNAL);
  } while (ret == -1 && errno == EINTR); /* Loop until not interrupted */

  UNMASK_SIGNAL();

  return ret;
}

int GSocket::Send_Dgram(const char *buffer, int size)
{
  struct sockaddr *addr;
  int len, ret;
  GSocketError err;

  if (!m_peer)
  {
    m_error = GSOCK_INVADDR;
    return -1;
  }

  err = _GAddress_translate_to(m_peer, &addr, &len);
  if (err != GSOCK_NOERROR)
  {
    m_error = err;
    return -1;
  }

  MASK_SIGNAL();

  do
  {
    ret = sendto(m_fd, (char *)buffer, size, 0, addr, len);
  } while (ret == -1 && errno == EINTR); /* Loop until not interrupted */

  UNMASK_SIGNAL();

  /* Frees memory allocated from _GAddress_translate_to */
  free(addr);

  return ret;
}

void GSocket::Detected_Read()
{
  char c;

  /* Safeguard against straggling call to Detected_Read */
  if (m_fd == INVALID_SOCKET)
  {
    return;
  }

  /* If we have already detected a LOST event, then don't try
   * to do any further processing.
   */
  if ((m_detected & GSOCK_LOST_FLAG) != 0)
  {
    m_establishing = false;

    CALL_CALLBACK(this, GSOCK_LOST);
    Shutdown();
    return;
  }

  int num =  recv(m_fd, &c, 1, MSG_PEEK | GSOCKET_MSG_NOSIGNAL);

  if (num > 0)
  {
    CALL_CALLBACK(this, GSOCK_INPUT);
  }
  else
  {
    if (m_server && m_stream)