C++ (Cpp) _dbus_create_file_exclusively Examples

Example #1

File: dbus-keyring.c Project: jameshilliard/WECB-BH-GPL

static dbus_bool_t
_dbus_keyring_lock (DBusKeyring *keyring)
{
  int n_timeouts;
  
  n_timeouts = 0;
  while (n_timeouts < MAX_LOCK_TIMEOUTS)
    {
      DBusError error;

      dbus_error_init (&error);
      if (_dbus_create_file_exclusively (&keyring->filename_lock,
                                         &error))
        break;

      _dbus_verbose ("Did not get lock file, sleeping %d milliseconds (%s)\n",
                     LOCK_TIMEOUT_MILLISECONDS, error.message);
      dbus_error_free (&error);

      _dbus_sleep_milliseconds (LOCK_TIMEOUT_MILLISECONDS);
      
      ++n_timeouts;
    }

  if (n_timeouts == MAX_LOCK_TIMEOUTS)
    {
      DBusError error;
      
      _dbus_verbose ("Lock file timed out %d times, assuming stale\n",
                     n_timeouts);

      dbus_error_init (&error);

      if (!_dbus_delete_file (&keyring->filename_lock, &error))
        {
          _dbus_verbose ("Couldn't delete old lock file: %s\n",
                         error.message);
          dbus_error_free (&error);
          return FALSE;
        }

      if (!_dbus_create_file_exclusively (&keyring->filename_lock,
                                          &error))
        {
          _dbus_verbose ("Couldn't create lock file after deleting stale one: %s\n",
                         error.message);
          dbus_error_free (&error);
          return FALSE;
        }
    }
  
  return TRUE;
}

Example #2

File: dbus-internals.c Project: psunkari/spicebird

static dbus_bool_t
_dbus_create_uuid_file_exclusively (const DBusString *filename,
                                    DBusGUID         *uuid,
                                    DBusError        *error)
{
  DBusString encoded;

  if (!_dbus_string_init (&encoded))
    {
      _DBUS_SET_OOM (error);
      return FALSE;
    }

  _dbus_generate_uuid (uuid);
  
  if (!_dbus_uuid_encode (uuid, &encoded))
    {
      _DBUS_SET_OOM (error);
      goto error;
    }
  
  /* FIXME this is racy; we need a save_file_exclusively
   * function. But in practice this should be fine for now.
   *
   * - first be sure we can create the file and it
   *   doesn't exist by creating it empty with O_EXCL
   * - then create it by creating a temporary file and
   *   overwriting atomically with rename()
   */
  if (!_dbus_create_file_exclusively (filename, error))
    goto error;

  if (!_dbus_string_append_byte (&encoded, '\n'))
    {
      _DBUS_SET_OOM (error);
      goto error;
    }
  
  if (!_dbus_string_save_to_file (&encoded, filename, error))
    goto error;

  if (!_dbus_make_file_world_readable (filename, error))
    goto error;

  _dbus_string_free (&encoded);

  _DBUS_ASSERT_ERROR_IS_CLEAR (error);
  return TRUE;
  
 error:
  _DBUS_ASSERT_ERROR_IS_SET (error);
  _dbus_string_free (&encoded);
  return FALSE;        
}