cec-poll — Wait for some event on a file descriptor
#include <sys/poll.h>
int poll( | struct pollfd *ufds, |
unsigned int nfds, | |
int timeout) ; |
Note: this documents the proposed CEC API. This API is not yet finalized and is currently only available as a staging kernel module.
With the poll()
function applications
can wait for CEC events.
On success poll()
returns the number of
file descriptors that have been selected (that is, file descriptors
for which the revents
field of the
respective pollfd structure is non-zero).
CEC devices set the POLLIN
and
POLLRDNORM
flags in the
revents
field if there are messages in the
receive queue. If the transmit queue has room for new messages, the
POLLOUT
and POLLWRNORM
flags are set. If there are events in the event queue, then the
POLLPRI
flag is set.
When the function timed out it returns a value of zero, on
failure it returns -1 and the
errno
variable is set appropriately.
For more details see the
poll()
manual page.
On success, poll()
returns the number
structures which have non-zero revents
fields, or zero if the call timed out. On error
-1 is returned, and the
errno
variable is set appropriately:
One or more of the ufds
members
specify an invalid file descriptor.
ufds
references an inaccessible
memory area.
The call was interrupted by a signal.
The nfds
argument is greater
than OPEN_MAX
.