nbd_poll2 - Man Page

poll the handle once, with fd


 #include <libnbd.h>

 int nbd_poll2 (
       struct nbd_handle *h, int fd, int timeout


This is the same as nbd_poll(3), but an additional file descriptor parameter is passed.  The additional fd is also polled (using POLLIN).  One use for this is to wait for an eventfd(2).

Return Value

This call returns an integer ≥ 0.


On error -1 is returned.

Refer to "ERROR HANDLING" in libnbd(3) for how to get further details of the error.

The following parameters must not be NULL: h. For more information see "Non-NULL parameters" in libnbd(3).


This function first appeared in libnbd 1.16.

If you need to test if this function is available at compile time check if the following macro is defined:


See Also

nbd_create(3), nbd_poll(3), libnbd(3), eventfd(2).


Eric Blake

Richard W.M. Jones


This library is free software; you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version.

This library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public License for more details.

You should have received a copy of the GNU Lesser General Public License along with this library; if not, write to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA

Referenced By

libnbd(3), libnbd-release-notes-1.16(1), nbd_poll(3).

2023-09-08 libnbd-1.17.5