706f8a9975
There are several notes and warning mesages in the middle of the media docbook. Use the ReST tags for that, as it makes them visually better and hightlights them. While here, modify a few ones to make them clearer. Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
71 lines
1.7 KiB
ReStructuredText
71 lines
1.7 KiB
ReStructuredText
.. -*- coding: utf-8; mode: rst -*-
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.. _cec-func-poll:
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**********
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cec poll()
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**********
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Name
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====
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cec-poll - Wait for some event on a file descriptor
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Synopsis
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========
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.. code-block:: c
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#include <sys/poll.h>
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.. cpp:function:: int poll( struct pollfd *ufds, unsigned int nfds, int timeout )
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Arguments
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=========
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Description
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===========
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.. note:: This documents the proposed CEC API. This API is not yet finalized
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and is currently only available as a staging kernel module.
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With the :c:func:`poll()` function applications can wait for CEC
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events.
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On success :c:func:`poll()` returns the number of file descriptors
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that have been selected (that is, file descriptors for which the
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``revents`` field of the respective :c:type:`struct pollfd` structure
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is non-zero). CEC devices set the ``POLLIN`` and ``POLLRDNORM`` flags in
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the ``revents`` field if there are messages in the receive queue. If the
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transmit queue has room for new messages, the ``POLLOUT`` and
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``POLLWRNORM`` flags are set. If there are events in the event queue,
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then the ``POLLPRI`` flag is set. When the function timed out it returns
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a value of zero, on failure it returns -1 and the ``errno`` variable is
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set appropriately.
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For more details see the :c:func:`poll()` manual page.
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Return Value
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============
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On success, :c:func:`poll()` returns the number structures which have
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non-zero ``revents`` fields, or zero if the call timed out. On error -1
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is returned, and the ``errno`` variable is set appropriately:
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``EBADF``
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One or more of the ``ufds`` members specify an invalid file
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descriptor.
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``EFAULT``
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``ufds`` references an inaccessible memory area.
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``EINTR``
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The call was interrupted by a signal.
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``EINVAL``
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The ``nfds`` argument is greater than ``OPEN_MAX``.
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