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Diffstat (limited to 'Documentation/media/uapi/mediactl/request-func-poll.rst')
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diff --git a/Documentation/media/uapi/mediactl/request-func-poll.rst b/Documentation/media/uapi/mediactl/request-func-poll.rst deleted file mode 100644 index ebaf33e21873..000000000000 --- a/Documentation/media/uapi/mediactl/request-func-poll.rst +++ /dev/null @@ -1,101 +0,0 @@ -.. This file is dual-licensed: you can use it either under the terms -.. of the GPL 2.0 or the GFDL 1.1+ license, at your option. Note that this -.. dual licensing only applies to this file, and not this project as a -.. whole. -.. -.. a) This file is free software; you can redistribute it and/or -.. modify it under the terms of the GNU General Public License as -.. published by the Free Software Foundation version 2 of -.. the License. -.. -.. This file 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 General Public License for more details. -.. -.. Or, alternatively, -.. -.. b) Permission is granted to copy, distribute and/or modify this -.. document under the terms of the GNU Free Documentation License, -.. Version 1.1 or any later version published by the Free Software -.. Foundation, with no Invariant Sections, no Front-Cover Texts -.. and no Back-Cover Texts. A copy of the license is included at -.. Documentation/media/uapi/fdl-appendix.rst. -.. -.. TODO: replace it to GPL-2.0 OR GFDL-1.1-or-later WITH no-invariant-sections - -.. _request-func-poll: - -************** -request poll() -************** - -Name -==== - -request-poll - Wait for some event on a file descriptor - - -Synopsis -======== - -.. code-block:: c - - #include <sys/poll.h> - - -.. c:function:: int poll( struct pollfd *ufds, unsigned int nfds, int timeout ) - :name: request-poll - -Arguments -========= - -``ufds`` - List of file descriptor events to be watched - -``nfds`` - Number of file descriptor events at the \*ufds array - -``timeout`` - Timeout to wait for events - - -Description -=========== - -With the :c:func:`poll() <request-func-poll>` function applications can wait -for a request to complete. - -On success :c:func:`poll() <request-func-poll>` returns the number of file -descriptors that have been selected (that is, file descriptors for which the -``revents`` field of the respective struct :c:type:`pollfd` -is non-zero). Request file descriptor set the ``POLLPRI`` flag in ``revents`` -when the request was completed. When the function times out it returns -a value of zero, on failure it returns -1 and the ``errno`` variable is -set appropriately. - -Attempting to poll for a request that is not yet queued will -set the ``POLLERR`` flag in ``revents``. - - -Return Value -============ - -On success, :c:func:`poll() <request-func-poll>` returns the number of -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: - -``EBADF`` - One or more of the ``ufds`` members specify an invalid file - descriptor. - -``EFAULT`` - ``ufds`` references an inaccessible memory area. - -``EINTR`` - The call was interrupted by a signal. - -``EINVAL`` - The ``nfds`` value exceeds the ``RLIMIT_NOFILE`` value. Use - ``getrlimit()`` to obtain this value. |