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diff --git a/man/sd_event_add_io.xml b/man/sd_event_add_io.xml deleted file mode 100644 index c3749164cd..0000000000 --- a/man/sd_event_add_io.xml +++ /dev/null @@ -1,300 +0,0 @@ -<?xml version='1.0'?> <!--*- Mode: nxml; nxml-child-indent: 2; indent-tabs-mode: nil -*--> -<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN" -"http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd"> - -<!-- - This file is part of systemd. - - Copyright 2015 Lennart Poettering - - systemd 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 2.1 of the License, or - (at your option) any later version. - - systemd 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 systemd; If not, see <http://www.gnu.org/licenses/>. ---> - -<refentry id="sd_event_add_io" xmlns:xi="http://www.w3.org/2001/XInclude"> - - <refentryinfo> - <title>sd_event_add_io</title> - <productname>systemd</productname> - - <authorgroup> - <author> - <contrib>Developer</contrib> - <firstname>Lennart</firstname> - <surname>Poettering</surname> - <email>lennart@poettering.net</email> - </author> - </authorgroup> - </refentryinfo> - - <refmeta> - <refentrytitle>sd_event_add_io</refentrytitle> - <manvolnum>3</manvolnum> - </refmeta> - - <refnamediv> - <refname>sd_event_add_io</refname> - <refname>sd_event_source_get_io_events</refname> - <refname>sd_event_source_set_io_events</refname> - <refname>sd_event_source_get_io_revents</refname> - <refname>sd_event_source_get_io_fd</refname> - <refname>sd_event_source_set_io_fd</refname> - <refname>sd_event_source</refname> - <refname>sd_event_io_handler_t</refname> - - <refpurpose>Add an I/O event source to an event loop</refpurpose> - </refnamediv> - - <refsynopsisdiv> - <funcsynopsis> - <funcsynopsisinfo>#include <systemd/sd-event.h></funcsynopsisinfo> - - <funcsynopsisinfo><token>typedef</token> struct sd_event_source sd_event_source;</funcsynopsisinfo> - - <funcprototype> - <funcdef>typedef int (*<function>sd_event_io_handler_t</function>)</funcdef> - <paramdef>sd_event_source *<parameter>s</parameter></paramdef> - <paramdef>int <parameter>fd</parameter></paramdef> - <paramdef>uint32_t <parameter>revents</parameter></paramdef> - <paramdef>void *<parameter>userdata</parameter></paramdef> - </funcprototype> - - <funcprototype> - <funcdef>int <function>sd_event_add_io</function></funcdef> - <paramdef>sd_event *<parameter>event</parameter></paramdef> - <paramdef>sd_event_source **<parameter>source</parameter></paramdef> - <paramdef>int <parameter>fd</parameter></paramdef> - <paramdef>uint32_t <parameter>events</parameter></paramdef> - <paramdef>sd_event_io_handler_t <parameter>handler</parameter></paramdef> - <paramdef>void *<parameter>userdata</parameter></paramdef> - </funcprototype> - - <funcprototype> - <funcdef>int <function>sd_event_source_get_io_events</function></funcdef> - <paramdef>sd_event_source *<parameter>source</parameter></paramdef> - <paramdef>uint32_t *<parameter>events</parameter></paramdef> - </funcprototype> - - <funcprototype> - <funcdef>int <function>sd_event_source_set_io_events</function></funcdef> - <paramdef>sd_event_source *<parameter>source</parameter></paramdef> - <paramdef>uint32_t <parameter>events</parameter></paramdef> - </funcprototype> - - <funcprototype> - <funcdef>int <function>sd_event_source_get_io_revents</function></funcdef> - <paramdef>sd_event_source *<parameter>source</parameter></paramdef> - <paramdef>uint32_t *<parameter>revents</parameter></paramdef> - </funcprototype> - - <funcprototype> - <funcdef>int <function>sd_event_source_get_io_fd</function></funcdef> - <paramdef>sd_event_source *<parameter>source</parameter></paramdef> - </funcprototype> - - <funcprototype> - <funcdef>int <function>sd_event_source_set_io_fd</function></funcdef> - <paramdef>sd_event_source *<parameter>source</parameter></paramdef> - <paramdef>int <parameter>fd</parameter></paramdef> - </funcprototype> - - </funcsynopsis> - </refsynopsisdiv> - - <refsect1> - <title>Description</title> - - <para><function>sd_event_add_io()</function> adds a new I/O event - source to an event loop. The event loop object is specified in the - <parameter>event</parameter> parameter, the event source object is - returned in the <parameter>source</parameter> parameter. The - <parameter>fd</parameter> parameter takes the UNIX file descriptor - to watch, which may refer to a socket, a FIFO, a message queue, a - serial connection, a character device, or any other file descriptor - compatible with Linux - <citerefentry project='man-pages'><refentrytitle>epoll</refentrytitle><manvolnum>7</manvolnum></citerefentry>. The - <parameter>events</parameter> parameter takes a bit mask of events - to watch for, a combination of the following event flags: - <constant>EPOLLIN</constant>, <constant>EPOLLOUT</constant>, - <constant>EPOLLRDHUP</constant>, <constant>EPOLLPRI</constant>, - and <constant>EPOLLET</constant>, see - <citerefentry project='man-pages'><refentrytitle>epoll_ctl</refentrytitle><manvolnum>2</manvolnum></citerefentry> - for details. The <parameter>handler</parameter> shall reference a - function to call when the event source is triggered. The - <parameter>userdata</parameter> pointer will be passed to the - handler function, and may be chosen freely by the caller. The - handler will also be passed the file descriptor the event was seen - on, as well as the actual event flags. It's generally a subset of - the events watched, however may additionally include - <constant>EPOLLERR</constant> and <constant>EPOLLHUP</constant>. - </para> - - <para>By default, an event source will stay enabled - continuously (<constant>SD_EVENT_ON</constant>), but this may be - changed with - <citerefentry><refentrytitle>sd_event_source_set_enabled</refentrytitle><manvolnum>3</manvolnum></citerefentry>. - If the handler function returns a negative error code, it will be - disabled after the invocation, even if the - <constant>SD_EVENT_ON</constant> mode was requested before. Note - that an event source set to <constant>SD_EVENT_ON</constant> will - fire continuously unless data is read from or written to the file - descriptor to reset the mask of events seen. - </para> - - <para>Setting the I/O event mask to watch for to 0 does not mean - that the event source won't be triggered anymore, as - <constant>EPOLLHUP</constant> and <constant>EPOLLERR</constant> - may be triggered even with a zero event mask. To temporarily - disable an I/O event source use - <citerefentry><refentrytitle>sd_event_source_set_enabled</refentrytitle><manvolnum>3</manvolnum></citerefentry> - with <constant>SD_EVENT_OFF</constant> instead.</para> - - <para>To destroy an event source object use - <citerefentry><refentrytitle>sd_event_source_unref</refentrytitle><manvolnum>3</manvolnum></citerefentry>, - but note that the event source is only removed from the event loop - when all references to the event source are dropped. To make sure - an event source does not fire anymore, even if it is still referenced, - disable the event source using - <citerefentry><refentrytitle>sd_event_source_set_enabled</refentrytitle><manvolnum>3</manvolnum></citerefentry> - with <constant>SD_EVENT_OFF</constant>.</para> - - <para>If the second parameter of - <function>sd_event_add_io()</function> is - <constant>NULL</constant> no reference to the event source object - is returned. In this case the event source is considered - "floating", and will be destroyed implicitly when the event loop - itself is destroyed.</para> - - <para>It is recommended to use - <function>sd_event_add_io()</function> only in conjunction with - file descriptors that have <constant>O_NONBLOCK</constant> set, to - ensure that all I/O operations from invoked handlers are properly - asynchronous and non-blocking. Using file descriptors without - <constant>O_NONBLOCK</constant> might result in unexpected - starvation of other event sources. See - <citerefentry project='man-pages'><refentrytitle>fcntl</refentrytitle><manvolnum>2</manvolnum></citerefentry> - for details on enabling <constant>O_NONBLOCK</constant> mode.</para> - - <para><function>sd_event_source_get_io_events()</function> retrieves - the configured mask of watched I/O events of an event source created - previously with <function>sd_event_add_io()</function>. It takes - the event source object and a pointer to a variable to store the - mask in.</para> - - <para><function>sd_event_source_set_io_events()</function> - configures the mask of watched I/O events of an event source created - previously with <function>sd_event_add_io()</function>. It takes the - event source object and the new event mask.</para> - - <para><function>sd_event_source_get_io_revents()</function> - retrieves the I/O event mask of currently seen but undispatched - events from an event source created previously with - <function>sd_event_add_io()</function>. It takes the event source - object and a pointer to a variable to store the event mask - in. When called from a handler function on the handler's event - source object this will return the same mask as passed to the - handler's <parameter>revents</parameter> parameter. This call is - primarily useful to check for undispatched events of an event - source from the handler of an unrelated (possibly higher priority) - event source. Note the relation between - <function>sd_event_source_get_pending()</function> and - <function>sd_event_source_get_io_revents()</function>: both - functions will report non-zero results when there's an event - pending for the event source, but the former applies to all event - source types, the latter only to I/O event sources.</para> - - <para><function>sd_event_source_get_io_fd()</function> retrieves - the UNIX file descriptor of an event source created previously - with <function>sd_event_add_io()</function>. It takes the event - source object and returns the non-negative file descriptor - or a negative error number on error (see below).</para> - - <para><function>sd_event_source_set_io_fd()</function> - changes the UNIX file descriptor of an I/O event source created - previously with <function>sd_event_add_io()</function>. It takes - the event source object and the new file descriptor.</para> - </refsect1> - - <refsect1> - <title>Return Value</title> - - <para>On success, these functions return 0 or a positive - integer. On failure, they return a negative errno-style error - code.</para> - </refsect1> - - <refsect1> - <title>Errors</title> - - <para>Returned values may indicate the following problems:</para> - - <variablelist> - <varlistentry> - <term><constant>-ENOMEM</constant></term> - - <listitem><para>Not enough memory to allocate an object.</para></listitem> - </varlistentry> - - <varlistentry> - <term><constant>-EINVAL</constant></term> - - <listitem><para>An invalid argument has been passed.</para></listitem> - - </varlistentry> - - <varlistentry> - <term><constant>-ESTALE</constant></term> - - <listitem><para>The event loop is already terminated.</para></listitem> - - </varlistentry> - - <varlistentry> - <term><constant>-ECHILD</constant></term> - - <listitem><para>The event loop has been created in a different process.</para></listitem> - </varlistentry> - - <varlistentry> - <term><constant>-EDOM</constant></term> - - <listitem><para>The passed event source is not an I/O event source.</para></listitem> - </varlistentry> - </variablelist> - </refsect1> - - <xi:include href="libsystemd-pkgconfig.xml" /> - - <refsect1> - <title>See Also</title> - - <para> - <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>, - <citerefentry><refentrytitle>sd-event</refentrytitle><manvolnum>3</manvolnum></citerefentry>, - <citerefentry><refentrytitle>sd_event_new</refentrytitle><manvolnum>3</manvolnum></citerefentry>, - <citerefentry><refentrytitle>sd_event_now</refentrytitle><manvolnum>3</manvolnum></citerefentry>, - <citerefentry><refentrytitle>sd_event_add_time</refentrytitle><manvolnum>3</manvolnum></citerefentry>, - <citerefentry><refentrytitle>sd_event_add_signal</refentrytitle><manvolnum>3</manvolnum></citerefentry>, - <citerefentry><refentrytitle>sd_event_add_child</refentrytitle><manvolnum>3</manvolnum></citerefentry>, - <citerefentry><refentrytitle>sd_event_add_defer</refentrytitle><manvolnum>3</manvolnum></citerefentry>, - <citerefentry><refentrytitle>sd_event_source_set_enabled</refentrytitle><manvolnum>3</manvolnum></citerefentry>, - <citerefentry><refentrytitle>sd_event_source_set_priority</refentrytitle><manvolnum>3</manvolnum></citerefentry>, - <citerefentry><refentrytitle>sd_event_source_set_userdata</refentrytitle><manvolnum>3</manvolnum></citerefentry>, - <citerefentry><refentrytitle>sd_event_source_set_description</refentrytitle><manvolnum>3</manvolnum></citerefentry>, - <citerefentry><refentrytitle>sd_event_source_get_pending</refentrytitle><manvolnum>3</manvolnum></citerefentry>, - <citerefentry project='man-pages'><refentrytitle>epoll_ctl</refentrytitle><manvolnum>3</manvolnum></citerefentry>, - <citerefentry project='man-pages'><refentrytitle>epoll</refentrytitle><manvolnum>7</manvolnum></citerefentry> - </para> - </refsect1> - -</refentry> |