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| author | Lennart Poettering <lennart@poettering.net> | 2015-11-19 23:38:54 +0100 |
|---|---|---|
| committer | Lennart Poettering <lennart@poettering.net> | 2015-11-19 23:38:54 +0100 |
| commit | dc83f27a7cf03757dec11a69ec18504ad4ea8f89 (patch) | |
| tree | 54af47fe95cdaa44ea4f0e3c0c3482e40c46edc3 /man | |
| parent | 0be6c2f617732902921d42bb0705f016b2838aba (diff) | |
| download | systemd-dc83f27a7cf03757dec11a69ec18504ad4ea8f89.tar.gz | |
man: fully document sd-event interfaces
This completes the set of man pages for sd-event and contains some minor
other fixes for other man pages too.
The sd_event_set_name(3) man page is renamed to
sd_event_source_set_description(3), which is the correct name of the
concept today.
Diffstat (limited to 'man')
25 files changed, 2882 insertions, 497 deletions
diff --git a/man/sd-daemon.xml b/man/sd-daemon.xml index b7ba363656..b06d99f346 100644 --- a/man/sd-daemon.xml +++ b/man/sd-daemon.xml @@ -71,10 +71,10 @@ <refsect1> <title>Description</title> - <para><filename>sd-daemon.h</filename> provide APIs for new-style + <para><filename>sd-daemon.h</filename> provides APIs for new-style daemons, as implemented by the <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry> - init system.</para> + service manager.</para> <para>See <citerefentry><refentrytitle>sd_listen_fds</refentrytitle><manvolnum>3</manvolnum></citerefentry>, diff --git a/man/sd-event.xml b/man/sd-event.xml new file mode 100644 index 0000000000..47989f4421 --- /dev/null +++ b/man/sd-event.xml @@ -0,0 +1,187 @@ +<?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" xmlns:xi="http://www.w3.org/2001/XInclude"> + + <refentryinfo> + <title>sd-event</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</refentrytitle> + <manvolnum>3</manvolnum> + </refmeta> + + <refnamediv> + <refname>sd-event</refname> + <refpurpose>A generic event loop implementation</refpurpose> + </refnamediv> + + <refsynopsisdiv> + <funcsynopsis> + <funcsynopsisinfo>#include <systemd/sd-event.h></funcsynopsisinfo> + </funcsynopsis> + + <cmdsynopsis> + <command>pkg-config --cflags --libs libsystemd</command> + </cmdsynopsis> + + </refsynopsisdiv> + + <refsect1> + <title>Description</title> + + <para><filename>sd-event.h</filename> provides a generic event + loop implementation, based on Linux <citerefentry + project='man-pages'><refentrytitle>epoll</refentrytitle><manvolnum>7</manvolnum></citerefentry>. + </para> + + <para>See + <citerefentry><refentrytitle>sd_event_new</refentrytitle><manvolnum>3</manvolnum></citerefentry>, + <citerefentry><refentrytitle>sd_event_run</refentrytitle><manvolnum>3</manvolnum></citerefentry>, + <citerefentry><refentrytitle>sd_event_add_io</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_unref</refentrytitle><manvolnum>3</manvolnum></citerefentry>, + <citerefentry><refentrytitle>sd_event_source_set_priority</refentrytitle><manvolnum>3</manvolnum></citerefentry>, + <citerefentry><refentrytitle>sd_event_source_set_enabled</refentrytitle><manvolnum>3</manvolnum></citerefentry>, + <citerefentry><refentrytitle>sd_event_source_set_userdata</refentrytitle><manvolnum>3</manvolnum></citerefentry>, + <citerefentry><refentrytitle>sd_event_source_get_event</refentrytitle><manvolnum>3</manvolnum></citerefentry>, + <citerefentry><refentrytitle>sd_event_source_get_pending</refentrytitle><manvolnum>3</manvolnum></citerefentry>, + <citerefentry><refentrytitle>sd_event_source_set_description</refentrytitle><manvolnum>3</manvolnum></citerefentry>, + <citerefentry><refentrytitle>sd_event_source_set_prepare</refentrytitle><manvolnum>3</manvolnum></citerefentry>, + <citerefentry><refentrytitle>sd_event_wait</refentrytitle><manvolnum>3</manvolnum></citerefentry>, + <citerefentry><refentrytitle>sd_event_get_fd</refentrytitle><manvolnum>3</manvolnum></citerefentry>, + <citerefentry><refentrytitle>sd_event_set_watchdog</refentrytitle><manvolnum>3</manvolnum></citerefentry>, + <citerefentry><refentrytitle>sd_event_exit</refentrytitle><manvolnum>3</manvolnum></citerefentry>, + <citerefentry><refentrytitle>sd_event_now</refentrytitle><manvolnum>3</manvolnum></citerefentry> + for more information about the functions available.</para> + + <para>The event loop design is targeted on running a separate + instance of the event loop in each thread; it has no concept of + distributing events from a single event loop instance onto + multiple worker threads. Dispatching events is strictly ordered + and subject to configurable priorities. In each event loop + iteration a single event source is dispatched. Each time an event + source is dispatched the kernel is polled for new events, before + the next event source is dispatched. The event loop is designed to + honour priorities and provide fairness within each priority. It is + not designed to provide optimal throughput, as this contradicts + these goals due the limitations of the underlying <citerefentry + project='man-pages'><refentrytitle>epoll</refentrytitle><manvolnum>7</manvolnum></citerefentry> + primitives.</para> + + <para>The event loop implementation provides the following features:</para> + + <orderedlist> + <listitem><para>I/O event sources, based on <citerefentry + project='man-pages'><refentrytitle>epoll</refentrytitle><manvolnum>7</manvolnum></citerefentry>'s + file descriptor watching, including edge triggered events (<constant>EPOLLET</constant>). See <citerefentry><refentrytitle>sd_event_add_io</refentrytitle><manvolnum>3</manvolnum></citerefentry>.</para></listitem> + + <listitem><para>Timer event sources, based on <citerefentry + project='man-pages'><refentrytitle>timerfd_create</refentrytitle><manvolnum>2</manvolnum></citerefentry>, + supporting the <constant>CLOCK_MONOTONIC</constant>, + <constant>CLOCK_REALTIME</constant>, + <constant>CLOCK_BOOTIME</constant> clocks, as well as the + <constant>CLOCK_REALTIME_ALARM</constant> and + <constant>CLOCK_BOOTTIME_ALARM</constant> clocks that can resume + the system from suspend. When creating timer events a required + accuracy parameter may be specified which allows coalescing of + timer events to minimize power consumption. See <citerefentry><refentrytitle>sd_event_add_time</refentrytitle><manvolnum>3</manvolnum></citerefentry>.</para></listitem> + + <listitem><para>UNIX process signal events, based on + <citerefentry + project='man-pages'><refentrytitle>signalfd</refentrytitle><manvolnum>2</manvolnum></citerefentry>, + including full support for real-time signals, and queued parameters. See <citerefentry><refentrytitle>sd_event_add_signal</refentrytitle><manvolnum>3</manvolnum></citerefentry>.</para></listitem> + + <listitem><para>Child process state change events, based on + <citerefentry project='man-pages'><refentrytitle>waitid</refentrytitle><manvolnum>2</manvolnum></citerefentry>. See <citerefentry><refentrytitle>sd_event_add_child</refentrytitle><manvolnum>3</manvolnum></citerefentry>.</para></listitem> + + <listitem><para>Static event sources, of three types: defer, + post and exit, for invoking calls in each event loop, after + other event sources or at event loop termination. See + <citerefentry><refentrytitle>sd_event_add_defer</refentrytitle><manvolnum>3</manvolnum></citerefentry>.</para></listitem> + + <listitem><para>Event sources may be assigned a 64bit priority + value, that controls the order in which event sources are + dispatched if multiple are pending simultanously. See + <citerefentry><refentrytitle>sd_event_source_set_priority</refentrytitle><manvolnum>3</manvolnum></citerefentry>.</para></listitem> + + <listitem><para>The event loop may automatically send watchdog + notification messages to the service manager. See + <citerefentry><refentrytitle>sd_event_set_watchdog</refentrytitle><manvolnum>3</manvolnum></citerefentry>.</para></listitem> + + <listitem><para>The event loop may be integrated into foreign + event loops, such as the GLib one. See + <citerefentry><refentrytitle>sd_event_get_fd</refentrytitle><manvolnum>3</manvolnum></citerefentry> + for an example.</para></listitem> + </orderedlist> + + </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_new</refentrytitle><manvolnum>3</manvolnum></citerefentry>, + <citerefentry><refentrytitle>sd_event_run</refentrytitle><manvolnum>3</manvolnum></citerefentry>, + <citerefentry><refentrytitle>sd_event_add_io</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_unref</refentrytitle><manvolnum>3</manvolnum></citerefentry>, + <citerefentry><refentrytitle>sd_event_source_set_priority</refentrytitle><manvolnum>3</manvolnum></citerefentry>, + <citerefentry><refentrytitle>sd_event_source_set_enabled</refentrytitle><manvolnum>3</manvolnum></citerefentry>, + <citerefentry><refentrytitle>sd_event_source_set_userdata</refentrytitle><manvolnum>3</manvolnum></citerefentry>, + <citerefentry><refentrytitle>sd_event_source_get_event</refentrytitle><manvolnum>3</manvolnum></citerefentry>, + <citerefentry><refentrytitle>sd_event_source_get_pending</refentrytitle><manvolnum>3</manvolnum></citerefentry>, + <citerefentry><refentrytitle>sd_event_source_set_description</refentrytitle><manvolnum>3</manvolnum></citerefentry>, + <citerefentry><refentrytitle>sd_event_source_set_prepare</refentrytitle><manvolnum>3</manvolnum></citerefentry>, + <citerefentry><refentrytitle>sd_event_wait</refentrytitle><manvolnum>3</manvolnum></citerefentry>, + <citerefentry><refentrytitle>sd_event_get_fd</refentrytitle><manvolnum>3</manvolnum></citerefentry>, + <citerefentry><refentrytitle>sd_event_set_watchdog</refentrytitle><manvolnum>3</manvolnum></citerefentry>, + <citerefentry><refentrytitle>sd_event_exit</refentrytitle><manvolnum>3</manvolnum></citerefentry>, + <citerefentry><refentrytitle>sd_event_now</refentrytitle><manvolnum>3</manvolnum></citerefentry>, + <citerefentry project='man-pages'><refentrytitle>epoll</refentrytitle><manvolnum>7</manvolnum></citerefentry>, + <citerefentry project='man-pages'><refentrytitle>timerfd_create</refentrytitle><manvolnum>2</manvolnum></citerefentry>, + <citerefentry project='man-pages'><refentrytitle>signalfd</refentrytitle><manvolnum>2</manvolnum></citerefentry>, + <citerefentry project='man-pages'><refentrytitle>waitid</refentrytitle><manvolnum>2</manvolnum></citerefentry> + </para> + </refsect1> + +</refentry> diff --git a/man/sd_event_add_child.xml b/man/sd_event_add_child.xml index 77bec4e706..d4b180cf03 100644 --- a/man/sd_event_add_child.xml +++ b/man/sd_event_add_child.xml @@ -21,7 +21,7 @@ along with systemd; If not, see <http://www.gnu.org/licenses/>. --> -<refentry id="sd_event_add_child"> +<refentry id="sd_event_add_child" xmlns:xi="http://www.w3.org/2001/XInclude"> <refentryinfo> <title>sd_event_add_child</title> @@ -45,13 +45,23 @@ <refnamediv> <refname>sd_event_add_child</refname> <refname>sd_event_source_get_child_pid</refname> + <refname>sd_event_child_handler_t</refname> - <refpurpose>Add a child state change event source to an event loop</refpurpose> + <refpurpose>Add a child process state change event source to an event loop</refpurpose> </refnamediv> <refsynopsisdiv> <funcsynopsis> - <funcsynopsisinfo>#include <systemd/sd-bus.h></funcsynopsisinfo> + <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_child_handler_t</function>)</funcdef> + <paramdef>sd_event_source *<parameter>s</parameter></paramdef> + <paramdef>const siginfo_t *<parameter>si</parameter></paramdef> + <paramdef>void *<parameter>userdata</parameter></paramdef> + </funcprototype> <funcprototype> <funcdef>int <function>sd_event_add_child</function></funcdef> @@ -64,13 +74,6 @@ </funcprototype> <funcprototype> - <funcdef>typedef int (*<function>sd_event_child_handler_t</function>)</funcdef> - <paramdef>sd_event_source *<parameter>s</parameter></paramdef> - <paramdef>const siginfo_t *<parameter>si</parameter></paramdef> - <paramdef>void *<parameter>userdata</parameter></paramdef> - </funcprototype> - - <funcprototype> <funcdef>int <function>sd_event_source_get_child_pid</function></funcdef> <paramdef>sd_event_source *<parameter>source</parameter></paramdef> <paramdef>pid_t *<parameter>pid</parameter></paramdef> @@ -83,42 +86,75 @@ <title>Description</title> <para><function>sd_event_add_child()</function> adds a new child - state change event source to an event loop object. The event loop - is specified in <parameter>event</parameter>, the event source is - returned in the <parameter>source</parameter> parameter. The - <parameter>pid</parameter> parameter specifies the process to - watch. The <parameter>handler</parameter> must reference a - function to call when the process changes state. The handler - function will be passed the <parameter>userdata</parameter> - pointer, which may be chosen freely by the caller. The handler - also receives a pointer to a <structname>const - siginfo_t</structname> structure containing the information about - the event. The <parameter>options</parameter> parameter determines - which state changes will be watched for. It must contain an OR-ed - mask of <constant>WEXITED</constant> (watch for the child + process state change 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>pid</parameter> parameter specifies the PID of the + process to watch. The <parameter>handler</parameter> must + reference a function to call when the process changes state. The + handler function will be passed the + <parameter>userdata</parameter> pointer, which may be chosen + freely by the caller. The handler also receives a pointer to a + <structname>siginfo_t</structname> structure containing + information about the child process event. The + <parameter>options</parameter> parameter determines which state + changes will be watched for. It must contain an OR-ed mask of + <constant>WEXITED</constant> (watch for the child process terminating), <constant>WSTOPPED</constant> (watch for the child - being stopped by a signal), and <constant>WCONTINUED</constant> - (watch for the child being resumed by a signal). See - <citerefentry><refentrytitle>waitid</refentrytitle><manvolnum>2</manvolnum></citerefentry> + process being stopped by a signal), and + <constant>WCONTINUED</constant> (watch for the child process being + resumed by a signal). See <citerefentry + project='man-pages'><refentrytitle>waitid</refentrytitle><manvolnum>2</manvolnum></citerefentry> for further information.</para> <para>Only a single handler may be installed for a specific - child. The handler is enabled - for a single event (<constant>SD_EVENT_ONESHOT</constant>), - but this may be - changed with + child process. The handler is enabled for a single event + (<constant>SD_EVENT_ONESHOT</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 - <constant>SD_EVENT_ON</constant> mode is set. + disabled after the invocation, even if the + <constant>SD_EVENT_ON</constant> mode was requested before. </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 when there's still a + reference to it kept, consider setting the event source to + <constant>SD_EVENT_OFF</constant> with + <citerefentry><refentrytitle>sd_event_source_set_enabled</refentrytitle><manvolnum>3</manvolnum></citerefentry>.</para> + + <para>If the the second parameter of + <function>sd_event_add_child()</function> is passed as NULL 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>Note that the <parameter>handler</parameter> function is + invoked at a time where the child process is not reaped yet (and + thus still is exposed as a zombie process by the kernel). However, + the child will be reaped automatically after the function + returns. Child processes for which no child process state change + event sources are installed will not be reaped by the event loop + implementation.</para> + + <para>If both a child process state change event source and a + <constant>SIGCHLD</constant> signal event source is installed in + the same event loop, the configured event source priorities decide + which event source is dispatched first. If the signal handler is + processed first, it should leave the child processes for which + child process state change event sources are installed unreaped.</para> + <para><function>sd_event_source_get_child_pid()</function> - retrieves the configured <parameter>pid</parameter> of a child - state change event source created previously with + retrieves the configured PID of a child process state change event + source created previously with <function>sd_event_add_child()</function>. It takes the event source object as the <parameter>source</parameter> parameter and a - pointer to <type>pid_t</type> to return the result in. + pointer to a <type>pid_t</type> variable to return the process ID + in. </para> </refsect1> @@ -158,7 +194,7 @@ <term><constant>-EBUSY</constant></term> <listitem><para>A handler is already installed for this - child.</para></listitem> + child process.</para></listitem> </varlistentry> @@ -176,19 +212,17 @@ </varlistentry> - </variablelist> - </refsect1> + <varlistentry> + <term><constant>-EDOM</constant></term> - <refsect1> - <title>Notes</title> + <listitem><para>The passed event source is not a child process event source.</para></listitem> + </varlistentry> - <para><function>sd_event_add_child()</function> and the other functions - described here are available as a shared library, which can be - compiled and linked to with the - <constant>libsystemd</constant> <citerefentry project='die-net'><refentrytitle>pkg-config</refentrytitle><manvolnum>1</manvolnum></citerefentry> - file.</para> + </variablelist> </refsect1> + <xi:include href="libsystemd-pkgconfig.xml" /> + <refsect1> <title>See Also</title> @@ -196,10 +230,16 @@ <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_io</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_defer</refentrytitle><manvolnum>3</manvolnum></citerefentry>, - <citerefentry><refentrytitle>sd_event_source_set_enabled</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 project='man-pages'><refentrytitle>waitid</refentrytitle><manvolnum>2</manvolnum></citerefentry> </para> </refsect1> diff --git a/man/sd_event_add_defer.xml b/man/sd_event_add_defer.xml index 826f2fd224..6a13ede76e 100644 --- a/man/sd_event_add_defer.xml +++ b/man/sd_event_add_defer.xml @@ -21,7 +21,7 @@ along with systemd; If not, see <http://www.gnu.org/licenses/>. --> -<refentry id="sd_event_add_defer"> +<refentry id="sd_event_add_defer" xmlns:xi="http://www.w3.org/2001/XInclude"> <refentryinfo> <title>sd_event_add_defer</title> @@ -46,13 +46,22 @@ <refname>sd_event_add_defer</refname> <refname>sd_event_add_post</refname> <refname>sd_event_add_exit</refname> + <refname>sd_event_handler_t</refname> <refpurpose>Add static event sources to an event loop</refpurpose> </refnamediv> <refsynopsisdiv> <funcsynopsis> - <funcsynopsisinfo>#include <systemd/sd-bus.h></funcsynopsisinfo> + <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_handler_t</function>)</funcdef> + <paramdef>sd_event_source *<parameter>s</parameter></paramdef> + <paramdef>void *<parameter>userdata</parameter></paramdef> + </funcprototype> <funcprototype> <funcdef>int <function>sd_event_add_defer</function></funcdef> @@ -78,49 +87,67 @@ <paramdef>void *<parameter>userdata</parameter></paramdef> </funcprototype> - <funcprototype> - <funcdef>typedef int (*<function>sd_event_handler_t</function>)</funcdef> - <paramdef>sd_event_source *<parameter>s</parameter></paramdef> - <paramdef>void *<parameter>userdata</parameter></paramdef> - </funcprototype> - </funcsynopsis> </refsynopsisdiv> <refsect1> <title>Description</title> - <para>These three functions add new event sources to an event loop - object. The event loop is specified in - <parameter>event</parameter>, the event source is returned in the - <parameter>source</parameter> parameter. The event sources are - enabled statically and will "fire" when the event loop is run and - the conditions described below are met. The handler function will - be passed the <parameter>userdata</parameter> pointer, which may - be chosen freely by the caller.</para> + <para>These three functions add new static event sources 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 event + sources are enabled statically and will "fire" when the event loop + is run and the conditions described below are met. The handler + function will be passed the <parameter>userdata</parameter> + pointer, which may be chosen freely by the caller.</para> <para><function>sd_event_add_defer()</function> adds a new event - source that will "fire" the next time the event loop is run. By - default, the handler will be called once - (<constant>SD_EVENT_ONESHOT</constant>).</para> + source that will be dispatched instantly, before the event loop + goes to sleep again and waits for new events. By default, the + handler will be called once + (<constant>SD_EVENT_ONESHOT</constant>). Note that if the event + source is set to <constant>SD_EVENT_ON</constant> the event loop + will never go to sleep again, but continously call the handler, + possibly interleaved with other event sources.</para> <para><function>sd_event_add_post()</function> adds a new event - source that will "fire" if any event handlers are invoked whenever - the event loop is run. By default, the source is enabled - permanently (<constant>SD_EVENT_ON</constant>).</para> + source that is run before the event loop will sleep and wait + for new events, but only after at least one other non-post event + source was dispatched. By default, the source is enabled + permanently (<constant>SD_EVENT_ON</constant>). Note that this + event source type will still allow the event loop to go to sleep + again, even if set to <constant>SD_EVENT_ON</constant>, as long as + no other event source is ever triggered.</para> <para><function>sd_event_add_exit()</function> adds a new event - source that will "fire" when the event loop is terminated - with <function>sd_event_exit()</function>.</para> + source that will be dispatched when the event loop is terminated + with <citerefentry><refentrytitle>sd_event_exit</refentrytitle><manvolnum>3</manvolnum></citerefentry>.</para> <para>The <citerefentry><refentrytitle>sd_event_source_set_enabled</refentrytitle><manvolnum>3</manvolnum></citerefentry> function may be used to enable the event source permanently (<constant>SD_EVENT_ON</constant>) or to make it fire just once - (<constant>SD_EVENT_ONESHOT</constant>). If the handler function - returns a negative error code, it will be disabled after the - invocation, even if <constant>SD_EVENT_ON</constant> mode is - set.</para> + (<constant>SD_EVENT_ONESHOT</constant>).</para> + + <para>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.</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 when there's still a + reference to it kept, consider setting the event source to + <constant>SD_EVENT_OFF</constant> with + <citerefentry><refentrytitle>sd_event_source_set_enabled</refentrytitle><manvolnum>3</manvolnum></citerefentry>.</para> + + <para>If the second parameter of these functions is passed as + NULL 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> </refsect1> <refsect1> @@ -164,15 +191,7 @@ </variablelist> </refsect1> - <refsect1> - <title>Notes</title> - - <para>Functions described here are available as a shared library, - which can be compiled and linked to with the - <constant>libsystemd</constant> <citerefentry - project='die-net'><refentrytitle>pkg-config</refentrytitle><manvolnum>1</manvolnum></citerefentry> - file.</para> - </refsect1> + <xi:include href="libsystemd-pkgconfig.xml" /> <refsect1> <title>See Also</title> @@ -181,10 +200,16 @@ <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_io</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_source_set_enabled</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_exit</refentrytitle><manvolnum>3</manvolnum></citerefentry> </para> </refsect1> diff --git a/man/sd_event_add_io.xml b/man/sd_event_add_io.xml new file mode 100644 index 0000000000..e3ac407cdf --- /dev/null +++ b/man/sd_event_add_io.xml @@ -0,0 +1,300 @@ +<?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 I/O + events to watch the file descriptor 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 I/O event source is triggered. The + handler function will be passed the + <parameter>userdata</parameter> pointer, which 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 + seen. It's generally a subset of the events watched, however may + additionally have <constant>EPOLLERR</constant> and + <constant>EPOLLHUP</constant> set.</para> + + <para>By default, the I/O event source will stay enabled + continously (<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 I/O event source set to <constant>SD_EVENT_ON</constant> will + fire continously unless data is read or written to the file + descriptor in order 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 when there's still a + reference to it kept, consider setting the event source to + <constant>SD_EVENT_OFF</constant> with + <citerefentry><refentrytitle>sd_event_source_set_enabled</refentrytitle><manvolnum>3</manvolnum></citerefentry>.</para> + + <para>If the the second parameter of + <function>sd_event_add_io()</function> is passed as NULL 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 + starving 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 I/O event mask to watch of an I/O 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.</para> + + <para><function>sd_event_source_set_io_events()</function> changes the + configured I/O event mask to watch of an I/O event source created previously + with <function>sd_event_add_io()</function>. It takes the event + source object and the new event mask to set.</para> + + <para><function>sd_event_source_get_io_events()</function> + retrieves the I/O event mask of currently seen but undispatched + events from an I/O 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 I/O event source created previously + with <function>sd_event_add_io()</function>. It takes the event + source object and returns the positive file descriptor in the return + value, 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 to set.</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 errors 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> diff --git a/man/sd_event_add_signal.xml b/man/sd_event_add_signal.xml index 0923fe0ae7..b5312735d2 100644 --- a/man/sd_event_add_signal.xml +++ b/man/sd_event_add_signal.xml @@ -21,7 +21,7 @@ along with systemd; If not, see <http://www.gnu.org/licenses/>. --> -<refentry id="sd_event_add_signal"> +<refentry id="sd_event_add_signal" xmlns:xi="http://www.w3.org/2001/XInclude"> <refentryinfo> <title>sd_event_add_signal</title> @@ -45,13 +45,24 @@ <refnamediv> <refname>sd_event_add_signal</refname> <refname>sd_event_source_get_signal</refname> + <refname>sd_event_signal_handler_t</refname> - <refpurpose>Add a signal event source to an event loop</refpurpose> + <refpurpose>Add a UNIX process signal event source to an event + loop</refpurpose> </refnamediv> <refsynopsisdiv> <funcsynopsis> - <funcsynopsisinfo>#include <systemd/sd-bus.h></funcsynopsisinfo> + <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_signal_handler_t</function>)</funcdef> + <paramdef>sd_event_source *<parameter>s</parameter></paramdef> + <paramdef>const struct signalfd_siginfo *<parameter>si</parameter></paramdef> + <paramdef>void *<parameter>userdata</parameter></paramdef> + </funcprototype> <funcprototype> <funcdef>int <function>sd_event_add_signal</function></funcdef> @@ -63,13 +74,6 @@ </funcprototype> <funcprototype> - <funcdef>typedef int (*<function>sd_event_signal_handler_t</function>)</funcdef> - <paramdef>sd_event_source *<parameter>s</parameter></paramdef> - <paramdef>const struct signalfd_siginfo *<parameter>si</parameter></paramdef> - <paramdef>void *<parameter>userdata</parameter></paramdef> - </funcprototype> - - <funcprototype> <funcdef>int <function>sd_event_source_get_signal</function></funcdef> <paramdef>sd_event_source *<parameter>source</parameter></paramdef> </funcprototype> @@ -80,41 +84,61 @@ <refsect1> <title>Description</title> - <para><function>sd_event_add_signal()</function> adds a new signal - event source to an event loop object. The event loop is specified - in <parameter>event</parameter>, and the event source is returned in - the <parameter>source</parameter> parameter. The - <parameter>signal</parameter> parameter specifies the signal to be handled - (see - <citerefentry project='man-pages'><refentrytitle>signal</refentrytitle><manvolnum>7</manvolnum></citerefentry>). - The <parameter>handler</parameter> must reference a function to - call when the signal is delivered or be <constant>NULL</constant>. - The handler function will be passed the - <parameter>userdata</parameter> pointer, which may be chosen + <para><function>sd_event_add_signal()</function> adds a new UNIX + process signal event source to an event loop. The event loop + object is specified in the <parameter>event</parameter> parameter, + and the event source object is returned in the + <parameter>source</parameter> parameter. The + <parameter>signal</parameter> parameter specifies the numeric + signal to be handled (see <citerefentry + project='man-pages'><refentrytitle>signal</refentrytitle><manvolnum>7</manvolnum></citerefentry>). + The <parameter>handler</parameter> parameter must reference a + function to call when the signal is received or be + <constant>NULL</constant>. The handler function will be passed + the <parameter>userdata</parameter> pointer, which may be chosen freely by the caller. The handler also receives a pointer to a - <structname>const struct signalfd_siginfo</structname> containing - the information about the received signal. See - <citerefentry project='man-pages'><refentrytitle>signalfd</refentrytitle><manvolnum>2</manvolnum></citerefentry> + <structname>signalfd_siginfo</structname> structure containing + information about the received signal. See <citerefentry + project='man-pages'><refentrytitle>signalfd</refentrytitle><manvolnum>2</manvolnum></citerefentry> for further information.</para> <para>Only a single handler may be installed for a specific - signal. The signal will be unblocked, and must be - blocked when the function is called. If the handler is not - specified (<parameter>handler</parameter> is + signal. The signal will be unblocked by this call, and must be + blocked before this function is called in all threads (using + <citerefentry + project='man-pages'><refentrytitle>sigprocmask</refentrytitle><manvolnum>2</manvolnum></citerefentry>). If + the handler is not specified (<parameter>handler</parameter> is <constant>NULL</constant>), a default handler which causes the - program to exit will be used. By default, the handler is enabled - permanently (<constant>SD_EVENT_ON</constant>), but this may be - changed with + program to exit cleanly will be used.</para> + + <para>By default, the event source is enabled permanently + (<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 - <constant>SD_EVENT_ON</constant> mode is set. + disabled after the invocation, even if the + <constant>SD_EVENT_ON</constant> mode was requested before. </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 when there's still a + reference to it kept, consider setting the event source to + <constant>SD_EVENT_OFF</constant> with + <citerefentry><refentrytitle>sd_event_source_set_enabled</refentrytitle><manvolnum>3</manvolnum></citerefentry>.</para> + + <para>If the the second parameter of + <function>sd_event_add_signal()</function> is passed as NULL 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><function>sd_event_source_get_signal()</function> retrieves - the configured signal number of a signal event source created - previously with <function>sd_event_add_signal()</function>. It - takes the event source object as the <parameter>source</parameter> + the configured UNIX process signal number of a signal event source + created previously with + <function>sd_event_add_signal()</function>. It takes the event + source object as the <parameter>source</parameter> parameter.</para> </refsect1> @@ -168,19 +192,17 @@ </varlistentry> - </variablelist> - </refsect1> + <varlistentry> + <term><constant>-EDOM</constant></term> - <refsect1> - <title>Notes</title> + <listitem><para>The passed event source is not a signal event source.</para></listitem> + </varlistentry> - <para><function>sd_event_add_signal()</function> and the other functions - described here are available as a shared library, which can be - compiled and linked to with the - <constant>libsystemd</constant> <citerefentry project='die-net'><refentrytitle>pkg-config</refentrytitle><manvolnum>1</manvolnum></citerefentry> - file.</para> + </variablelist> </refsect1> + <xi:include href="libsystemd-pkgconfig.xml" /> + <refsect1> <title>See Also</title> @@ -188,10 +210,16 @@ <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_io</refentrytitle><manvolnum>3</manvolnum></citerefentry>, <citerefentry><refentrytitle>sd_event_add_time</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_enabled</refentrytitle><manvolnum>3</manvolnum></citerefentry>, + <citerefentry><refentrytitle>sd_event_source_set_description</refentrytitle><manvolnum>3</manvolnum></citerefentry>, + <citerefentry><refentrytitle>sd_event_source_set_userdata</refentrytitle><manvolnum>3</manvolnum></citerefentry>, + <citerefentry project='man-pages'><refentrytitle>signal</refentrytitle><manvolnum>7</manvolnum></citerefentry>, + <citerefentry project='man-pages'><refentrytitle>signalfd</refentrytitle><manvolnum>2</manvolnum></citerefentry> </para> </refsect1> diff --git a/man/sd_event_add_time.xml b/man/sd_event_add_time.xml index c5f7aee19d..df38f52fc9 100644 --- a/man/sd_event_add_time.xml +++ b/man/sd_event_add_time.xml @@ -21,7 +21,7 @@ along with systemd; If not, see <http://www.gnu.org/licenses/>. --> -<refentry id="sd_event_add_time"> +<refentry id="sd_event_add_time" xmlns:xi="http://www.w3.org/2001/XInclude"> <refentryinfo> <title>sd_event_add_time</title> @@ -49,13 +49,23 @@ <refname>sd_event_source_get_time_accuracy</refname> <refname>sd_event_source_set_time_accuracy</refname> <refname>sd_event_source_get_time_clock</refname> + <refname>sd_event_time_handler_t</refname> <refpurpose>Add a timer event source to an event loop</refpurpose> </refnamediv> <refsynopsisdiv> <funcsynopsis> - <funcsynopsisinfo>#include <systemd/sd-bus.h></funcsynopsisinfo> + <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_time_handler_t</function>)</funcdef> + <paramdef>sd_event_source *<parameter>s</parameter></paramdef> + <paramdef>uint64_t <parameter>usec</parameter></paramdef> + <paramdef>void *<parameter>userdata</parameter></paramdef> + </funcprototype> <funcprototype> <funcdef>int <function>sd_event_add_time</function></funcdef> @@ -69,34 +79,27 @@ </funcprototype> <funcprototype> - <funcdef>typedef int (*<function>sd_event_time_handler_t</function>)</funcdef> - <paramdef>sd_event_source *<parameter>s</parameter></paramdef> - <paramdef>uint64_t <parameter>usec</parameter></paramdef> - <paramdef>void *<parameter>userdata</parameter></paramdef> - </funcprototype> - - <funcprototype> <funcdef>int <function>sd_event_source_get_time</function></funcdef> <paramdef>sd_event_source *<parameter>source</parameter></paramdef> - <paramdef>usec_t *<parameter>usec</parameter></paramdef> + <paramdef>uint64_t *<parameter>usec</parameter></paramdef> </funcprototype> <funcprototype> <funcdef>int <function>sd_event_source_set_time</function></funcdef> <paramdef>sd_event_source *<parameter>source</parameter></paramdef> - <paramdef>usec_t <parameter>usec</parameter></paramdef> + <paramdef>uint64_t <parameter>usec</parameter></paramdef> </funcprototype> <funcprototype> <funcdef>int <function>sd_event_source_get_time_accuracy</function></funcdef> <paramdef>sd_event_source *<parameter>source</parameter></paramdef> - <paramdef>usec_t *<parameter>usec</parameter></paramdef> + <paramdef>uint64_t *<parameter>usec</parameter></paramdef> </funcprototype> <funcprototype> <funcdef>int <function>sd_event_source_set_time_accuracy</function></funcdef> <paramdef>sd_event_source *<parameter>source</parameter></paramdef> - <paramdef>usec_t <parameter>usec</parameter></paramdef> + <paramdef>uint64_t <parameter>usec</parameter></paramdef> </funcprototype> <funcprototype> @@ -112,73 +115,130 @@ <title>Description</title> <para><function>sd_event_add_time()</function> adds a new timer - event source to an event loop object. The event loop is specified - in <parameter>event</parameter>, the event source is returned in - the <parameter>source</parameter> parameter. The - <parameter>clock</parameter> parameter takes a clock identifier, - one of <constant>CLOCK_REALTIME</constant>, - <constant>CLOCK_MONOTONIC</constant> and + 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>clock</parameter> parameter takes a + clock identifier, one of <constant>CLOCK_REALTIME</constant>, + <constant>CLOCK_MONOTONIC</constant>, + <constant>CLOCK_BOOTTIME</constant>, + <constant>CLOCK_REALTIME_ALARM</constant> or <constant>CLOCK_BOOTTIME_ALARM</constant>. See <citerefentry><refentrytitle>timerfd_create</refentrytitle><manvolnum>2</manvolnum></citerefentry> for details regarding the various types of clocks. The <parameter>usec</parameter> parameter takes a time value in - microseconds, relative to the clock's epoch specifying when the - timer shall elapse the earliest. The + microseconds (µs), relative to the clock's epoch, specifying when + the timer shall elapse the earliest. If a time that already lies + in the past is specified (including 0), the timer source is + dispatched immediately in the next event loop iterations. The <parameter>accuracy</parameter> parameter takes an additional - accuracy value in microseconds specifying a time the timer event - may be delayed. Specify 0 for selecting the default accuracy - (250ms). Specify 1 for most accurate timers. Consider specifying - 60000000 or larger (1h) for long-running events that may be + accuracy value in µs specifying a time the timer event may be + delayed. Specify 0 for selecting the default accuracy + (250ms). Specify 1µs for most accurate timers. Consider specifying + 60000000µs or larger (1min) for long-running events that may be delayed substantially. Picking higher accuracy values allows the system to coalesce timer events more aggressively, thus improving - power efficiency. The <parameter>handler</parameter> shall - reference a function to call when the timer elapses. The handler - function will be passed the <parameter>userdata</parameter> - pointer, which may be chosen freely by the caller. The handler is - also passed the configured time it was triggered, however it might - actually have been called at a slightly later time, subject to the - specified accuracy value, the kernel timer slack (see + power efficiency. The <parameter>handler</parameter> parameter + shall reference a function to call when the timer elapses. The + handler function will be passed the + <parameter>userdata</parameter> pointer, which may be chosen + freely by the caller. The handler is also passed the configured + time it was triggered, however it might actually have been called + at a slightly later time, subject to the specified accuracy value, + the kernel timer slack (see <citerefentry><refentrytitle>prctl</refentrytitle><manvolnum>2</manvolnum></citerefentry>) - and additional scheduling latencies.</para> + and additional scheduling latencies. To query the actual time the + handler was called use + <citerefentry><refentrytitle>sd_event_now</refentrytitle><manvolnum>3</manvolnum></citerefentry>.</para> <para>By default, the timer will elapse once (<constant>SD_EVENT_ONESHOT</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 - <constant>SD_EVENT_ON</constant> mode is set. + disabled after the invocation, even if the + <constant>SD_EVENT_ON</constant> mode was requested before. Note + that a timer event set to <constant>SD_EVENT_ON</constant> will + fire continously unless its configured time is updated using + <function>sd_event_source_set_time()</function>. </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 when there's still a + reference to it kept, consider setting the event source to + <constant>SD_EVENT_OFF</constant> with + <citerefentry><refentrytitle>sd_event_source_set_enabled</refentrytitle><manvolnum>3</manvolnum></citerefentry>.</para> + + <para>If the the second parameter of + <function>sd_event_add_time()</function> is passed as NULL 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>If the <parameter>handler</parameter> to + <function>sd_event_add_time()</function> is passed as NULL, and + the event source fires, this will be considered a request to exit + the event loop. In this case, the <parameter>userdata</parameter> + parameter, cast to an integer is used for the exit code passed to + <citerefentry><refentrytitle>sd_event_exit</refentrytitle><manvolnum>3</manvolnum></citerefentry>.</para> + + <para>Use <constant>CLOCK_BOOTTIME_ALARM</constant> and + <constant>CLOCK_REALTIME_ALARM</constant> to define event sources + that may wake up the system from suspend.</para> + + <para>In order to set up relative timers (that is, relative to the + current time), retrieve the current time via + <citerefentry><refentrytitle>sd_event_now</refentrytitle><manvolnum>3</manvolnum></citerefentry>, + add the desired timespan to sleep to it, and pass the result as + the <parameter>usec</parameter> parameter to + <function>sd_event_add_time()</function>.</para> + + <para>In order to set up repetitive timers (that is, timers that + are triggered in regular intervals), set up the timer normally, + for the first invocation. Each time the event handler is invoked, + update the timer's trigger time with + <citerefentry><refentrytitle>sd_event_source_set_time</refentrytitle><manvolnum>3</manvolnum></citerefentry> for the next timer + iteration, and reenable the timer using + <function>sd_event_source_set_enabled()</function>. To calculate + the next point in time to pass to + <function>sd_event_source_set_time()</function>, either use as + base the <parameter>usec</parameter> parameter passed to the timer + callback, or the timestamp returned by + <function>sd_event_now()</function>. In the former case timer + events will be regular, while in the latter case the scheduling + latency will keep accumulating on the timer.</para> + <para><function>sd_event_source_get_time()</function> retrieves the configured time value of a timer event source created previously with <function>sd_event_add_time()</function>. It takes the event source object and a pointer to a variable to store the - time in microseconds in.</para> + time, relative to the selected clock's epoch, in µs in.</para> <para><function>sd_event_source_set_time()</function> changes the configured time value of a timer event source created previously with <function>sd_event_add_time()</function>. It takes the event source object and a time relative to the selected clock's - epoch, in microseconds.</para> + epoch, in µs.</para> <para><function>sd_event_source_get_time_accuracy()</function> retrieves the configured accuracy value of a timer event source created previously with <function>sd_event_add_time()</function>. It takes the event source object and a pointer to a variable to store - the accuracy in microseconds in.</para> + the accuracy in µs in.</para> <para><function>sd_event_source_set_time_accuracy()</function> changes the configured accuracy of a timer event source created previously with <function>sd_event_add_time()</function>. It takes - the event source object and an accuracy, in microseconds.</para> + the event source object and an accuracy, in µs.</para> <para><function>sd_event_source_get_time_clock()</function> retrieves the configured clock of a timer event source created previously with <function>sd_event_add_time()</function>. It takes the event source object and a pointer to a variable to store the clock identifier in.</para> - </refsect1> <refsect1> @@ -228,19 +288,17 @@ <listitem><para>The selected clock is not supported by the event loop implementation.</para></listitem> </varlistentry> - </variablelist> - </refsect1> - <refsect1> - <title>Notes</title> + <varlistentry> + <term><constant>-EDOM</constant></term> - <para><function>sd_event_add_time()</function> and the other functions - described here are available as a shared library, which can be - compiled and linked to with the - <constant>libsystemd</constant> <citerefentry project='die-net'><refentrytitle>pkg-config</refentrytitle><manvolnum>1</manvolnum></citerefentry> - file.</para> + <listitem><para>The passed event source is not a timer event source.</para></listitem> + </varlistentry> + </variablelist> </refsect1> + <xi:include href="libsystemd-pkgconfig.xml" /> + <refsect1> <title>See Also</title> @@ -248,11 +306,18 @@ <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_io</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>clock_gettime</refentrytitle><manvolnum>2</manvolnum></citerefentry>, - <citerefentry><refentrytitle>sd_event_source_set_enabled</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 project='man-pages'><refentrytitle>clock_gettime</refentrytitle><manvolnum>2</manvolnum></citerefentry>, + <citerefentry project='man-pages'><refentrytitle>timerfd_create</refentrytitle><manvolnum>2</manvolnum></citerefentry>, + <citerefentry project='man-pages'><refentrytitle>prctl</refentrytitle><manvolnum>2</manvolnum></citerefentry> </para> </refsect1> diff --git a/man/sd_event_exit.xml b/man/sd_event_exit.xml new file mode 100644 index 0000000000..4f34f3b122 --- /dev/null +++ b/man/sd_event_exit.xml @@ -0,0 +1,163 @@ +<?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_exit" xmlns:xi="http://www.w3.org/2001/XInclude"> + + <refentryinfo> + <title>sd_event_exit</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_exit</refentrytitle> + <manvolnum>3</manvolnum> + </refmeta> + + <refnamediv> + <refname>sd_event_exit</refname> + <refname>sd_event_get_exit_code</refname> + + <refpurpose>Ask the event loop to exit</refpurpose> + </refnamediv> + + <refsynopsisdiv> + <funcsynopsis> + <funcsynopsisinfo>#include <systemd/sd-event.h></funcsynopsisinfo> + + <funcprototype> + <funcdef>int <function>sd_event_exit</function></funcdef> + <paramdef>sd_event *<parameter>event</parameter></paramdef> + <paramdef>int <parameter>code</parameter></paramdef> + </funcprototype> + + <funcprototype> + <funcdef>int <function>sd_event_get_exit_code</function></funcdef> + <paramdef>sd_event *<parameter>event</parameter></paramdef> + <paramdef>int *<parameter>code</parameter></paramdef> + </funcprototype> + + </funcsynopsis> + </refsynopsisdiv> + + <refsect1> + <title>Description</title> + + <para><function>sd_event_exit()</function> requests the event loop + specified in the <parameter>event</parameter> event loop object to + exit. The <parameter>code</parameter> parameter may be any integer + value and is returned as-is by + <citerefentry><refentrytitle>sd_event_loop</refentrytitle><manvolnum>3</manvolnum></citerefentry> + after the last event loop iteration. It may also be be queried + using <function>sd_event_get_exit_code()</function>, see + below. </para> + + <para>When exiting is requested the event loop will stop listening + for and dispatching regular event sources. Instead it will proceed + with executing only event sources registered with + <citerefentry><refentrytitle>sd_event_add_exit</refentrytitle><manvolnum>3</manvolnum></citerefentry> + in the order defined by their priority. After all exit event + sources have been dispatched the event loop is terminated.</para> + + <para>If <function>sd_event_exit()</function> is invoked a second + time while the event loop is still processing exit event sources, + the exit code stored in the event loop object is updated, but + otherwise no further operation is executed.</para> + + <para><function>sd_event_get_exit_code()</function> may be used to + query the exit code passed into + <function>sd_event_exit()</function> earlier.</para> + + <para>While the full positive and negative integer ranges may be used + for the exit code, care should be taken not pick exit codes that + conflict with regular exit codes returned by + <function>sd_event_loop()</function>, if these exit codes shall be + distinguishable.</para> + </refsect1> + + <refsect1> + <title>Return Value</title> + + <para>On success, <function>sd_event_exit()</function> and + <function>sd_event_get_exit_code()</function> return 0 or a positive + integer. On failure, they return a negative errno-style error + code.</para> + </refsect1> + + <refsect1> + <title>Errors</title> + + <para>Returned errors may indicate the following problems:</para> + + <variablelist> + + <varlistentry> + <term><constant>-EINVAL</constant></term> + + <listitem><para>The event loop object or error code pointer are invalid.</para></listitem> + + </varlistentry> + + <varlistentry> + <term><constant>-ECHILD</constant></term> + + <listitem><para>The event loop was created in a different process.</para></listitem> + </varlistentry> + + <varlistentry> + <term><constant>-ESTALE</constant></term> + + <listitem><para>The event loop has exited already and all exit handlers are already processed.</para></listitem> + </varlistentry> + + <varlistentry> + <term><constant>-ENODATA</constant></term> + + <listitem><para>The event loop has not been requested to exit yet.</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_add_exit</refentrytitle><manvolnum>3</manvolnum></citerefentry> + </para> + </refsect1> + +</refentry> diff --git a/man/sd_event_get_fd.xml b/man/sd_event_get_fd.xml index ecdbe76ec4..f68752dd0e 100644 --- a/man/sd_event_get_fd.xml +++ b/man/sd_event_get_fd.xml @@ -21,8 +21,7 @@ along with systemd; If not, see <http://www.gnu.org/licenses/>. --> -<refentry id="sd_event_get_fd" - xmlns:xi="http://www.w3.org/2001/XInclude"> +<refentry id="sd_event_get_fd" xmlns:xi="http://www.w3.org/2001/XInclude"> <refentryinfo> <title>sd_event_get_fd</title> @@ -51,11 +50,11 @@ <refsynopsisdiv> <funcsynopsis> - <funcsynopsisinfo>#include <systemd/sd-bus.h></funcsynopsisinfo> + <funcsynopsisinfo>#include <systemd/sd-event.h></funcsynopsisinfo> <funcprototype> <funcdef>int <function>sd_event_get_fd</function></funcdef> - <paramdef>sd_bus *<parameter>event</parameter></paramdef> + <paramdef>sd_event *<parameter>event</parameter></paramdef> </funcprototype> </funcsynopsis> @@ -65,19 +64,29 @@ <title>Description</title> <para><function>sd_event_get_fd()</function> returns the file - descriptor that the event loop object returned by the + descriptor that an event loop object returned by the <citerefentry><refentrytitle>sd_event_new</refentrytitle><manvolnum>3</manvolnum></citerefentry> - function uses to wait for events. This file descriptor can be - polled for events. This makes it possible to embed the + function uses to wait for events. This file descriptor may itself + be polled for + <constant>POLLIN</constant>/<constant>EPOLLIN</constant> + events. This makes it possible to embed an <citerefentry><refentrytitle>sd-event</refentrytitle><manvolnum>3</manvolnum></citerefentry> - event loop inside of another event loop.</para> + event loop into another, possibly foreign, event loop.</para> + + <para>The returned file descriptor refers to an <citerefentry + project='man-pages'><refentrytitle>epoll</refentrytitle><manvolnum>7</manvolnum></citerefentry> + object. It is recommended not to alter it by invoking + <citerefentry + project='man-pages'><refentrytitle>epoll_ctl</refentrytitle><manvolnum>2</manvolnum></citerefentry> + on it, in order to avoid interference with the event loop's inner + logic and assumptions.</para> </refsect1> <refsect1> <title>Return Value</title> <para>On success, <function>sd_event_get_fd()</function> returns a - non-negative integer. On failure, it returns a negative + non-negative file descriptor. On failure, it returns a negative errno-style error code.</para> </refsect1> @@ -108,21 +117,13 @@ <title>Examples</title> <example> - <title>Integration in glib event loop</title> + <title>Integration in the GLib event loop</title> <programlisting><xi:include href="glib-event-glue.c" parse="text" /></programlisting> </example> </refsect1> - <refsect1> - <title>Notes</title> - - <para><function>sd_event_get_fd()</function> is available as a - shared library, which can be compiled and linked to with the - <constant>libsystemd</constant> <citerefentry - project='die-net'><refentrytitle>pkg-config</refentrytitle><manvolnum>1</manvolnum></citerefentry> - file.</para> - </refsect1> + <xi:include href="libsystemd-pkgconfig.xml" /> <refsect1> <title>See Also</title> @@ -130,7 +131,9 @@ <para> <citerefentry><refentrytitle>sd-event</refentrytitle><manvolnum>3</manvolnum></citerefentry>, <citerefentry><refentrytitle>sd_event_new</refentrytitle><manvolnum>3</manvolnum></citerefentry>, - <citerefentry><refentrytitle>sd_event_ref</refentrytitle><manvolnum>3</manvolnum></citerefentry> + <citerefentry><refentrytitle>sd_event_wait</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> diff --git a/man/sd_event_new.xml b/man/sd_event_new.xml index f6c5d39814..3356faa899 100644 --- a/man/sd_event_new.xml +++ b/man/sd_event_new.xml @@ -21,7 +21,7 @@ along with systemd; If not, see <http://www.gnu.org/licenses/>. --> -<refentry id="sd_event_new"> +<refentry id="sd_event_new" xmlns:xi="http://www.w3.org/2001/XInclude"> <refentryinfo> <title>sd_event_new</title> @@ -47,32 +47,42 @@ <refname>sd_event_default</refname> <refname>sd_event_ref</refname> <refname>sd_event_unref</refname> + <refname>sd_event_get_tid</refname> + <refname>sd_event</refname> <refpurpose>Acquire and release an event loop object</refpurpose> </refnamediv> <refsynopsisdiv> <funcsynopsis> - <funcsynopsisinfo>#include <systemd/sd-bus.h></funcsynopsisinfo> + <funcsynopsisinfo>#include <systemd/sd-event.h></funcsynopsisinfo> + + <funcsynopsisinfo><token>typedef</token> struct sd_event sd_event;</funcsynopsisinfo> <funcprototype> <funcdef>int <function>sd_event_new</function></funcdef> - <paramdef>sd_bus **<parameter>event</parameter></paramdef> + <paramdef>sd_event **<parameter>event</parameter></paramdef> </funcprototype> <funcprototype> <funcdef>int <function>sd_event_default</function></funcdef> - <paramdef>sd_bus **<parameter>event</parameter></paramdef> + <paramdef>sd_event **<parameter>event</parameter></paramdef> + </funcprototype> + + <funcprototype> + <funcdef>sd_event *<function>sd_event_ref</function></funcdef> + <paramdef>sd_event *<parameter>event</parameter></paramdef> </funcprototype> <funcprototype> - <funcdef>sd_bus *<function>sd_event_ref</function></funcdef> - <paramdef>sd_bus *<parameter>event</parameter></paramdef> + <funcdef>sd_event *<function>sd_event_unref</function></funcdef> + <paramdef>sd_event *<parameter>event</parameter></paramdef> </funcprototype> <funcprototype> - <funcdef>sd_bus *<function>sd_event_unref</function></funcdef> - <paramdef>sd_bus *<parameter>event</parameter></paramdef> + <funcdef>int <function>sd_event_get_tid</function></funcdef> + <paramdef>sd_event *<parameter>event</parameter></paramdef> + <paramdef>pid_t *<parameter>tid</parameter></paramdef> </funcprototype> </funcsynopsis> @@ -103,6 +113,17 @@ thread. All threads have exactly either zero or one default event loop objects associated, but never more.</para> + <para>After allocating an event loop object, add event sources to + it with + <citerefentry><refentrytitle>sd_event_add_io</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> + or + <citerefentry><refentrytitle>sd_event_add_defer</refentrytitle><manvolnum>3</manvolnum></citerefentry>, + and then execute the event loop using + <citerefentry><refentrytitle>sd_event_run</refentrytitle><manvolnum>3</manvolnum></citerefentry>.</para> + <para><function>sd_event_ref()</function> increases the reference count of the specified event loop object by one.</para> @@ -117,6 +138,19 @@ distinct objects. Note that, in order to free an event loop object, all remaining event sources of the event loop also need to be freed as each keeps a reference to it.</para> + + <para>Both <function>sd_event_ref()</function> and + <function>sd_event_unref()</function> execute no operation if the + passed in event loop object is <constant>NULL</constant>.</para> + + <para><function>sd_event_get_tid()</function> retrieves the thread + identifier ("TID") of the thread the specified event loop object + is associated with. This call is only supported for event loops + allocated with <function>sd_event_default()</function>, and + returns the identifier for the thread the event loop is the + default event loop of. See <citerefentry + project='man-pages'><refentrytitle>gettid</refentrytitle><manvolnum>2</manvolnum></citerefentry> + for more information on thread identifiers.</para> </refsect1> <refsect1> @@ -149,19 +183,20 @@ <listitem><para>The maximum number of event loops has been allocated.</para></listitem> </varlistentry> - </variablelist> - </refsect1> - <refsect1> - <title>Notes</title> + <varlistentry> + <term><constant>-ENXIO</constant></term> - <para><function>sd_event_new()</function> and the other functions - described here are available as a shared library, which can be - compiled and linked to with the - <constant>libsystemd</constant> <citerefentry project='die-net'><refentrytitle>pkg-config</refentrytitle><manvolnum>1</manvolnum></citerefentry> - file.</para> + <listitem><para><function>sd_event_get_tid()</function> was + invoked on an event loop object that was not allocated with + <function>sd_event_default()</function>.</para></listitem> + </varlistentry> + + </variablelist> </refsect1> + <xi:include href="libsystemd-pkgconfig.xml" /> + <refsect1> <title>See Also</title> @@ -174,7 +209,9 @@ <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_add_post</refentrytitle><manvolnum>3</manvolnum></citerefentry>, - <citerefentry><refentrytitle>sd_event_add_exit</refentrytitle><manvolnum>3</manvolnum></citerefentry> + <citerefentry><refentrytitle>sd_event_add_exit</refentrytitle><manvolnum>3</manvolnum></citerefentry>, + <citerefentry><refentrytitle>sd_event_run</refentrytitle><manvolnum>3</manvolnum></citerefentry>, + <citerefentry project='man-pages'><refentrytitle>gettid</refentrytitle><manvolnum>2</manvolnum></citerefentry> </para> </refsect1> diff --git a/man/sd_event_now.xml b/man/sd_event_now.xml new file mode 100644 index 0000000000..f577e44c0e --- /dev/null +++ b/man/sd_event_now.xml @@ -0,0 +1,141 @@ +<?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_now" xmlns:xi="http://www.w3.org/2001/XInclude"> + + <refentryinfo> + <title>sd_event_now</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_now</refentrytitle> + <manvolnum>3</manvolnum> + </refmeta> + + <refnamediv> + <refname>sd_event_now</refname> + + <refpurpose>Retrieve current event loop iteration timestamp</refpurpose> + </refnamediv> + + <refsynopsisdiv> + <funcsynopsis> + <funcsynopsisinfo>#include <systemd/sd-event.h></funcsynopsisinfo> + + <funcprototype> + <funcdef>int <function>sd_event_now</function></funcdef> + <paramdef>sd_event *<parameter>event</parameter></paramdef> + <paramdef>clockid_t <parameter>clock</parameter></paramdef> + <paramdef>uint64_t *<parameter>usec</parameter></paramdef> + </funcprototype> + + </funcsynopsis> + </refsynopsisdiv> + + <refsect1> + <title>Description</title> + + <para><function>sd_event_now()</function> returns the timestamp + the most recent event loop iteration began. This timestamp is + taken right after after returning from the event sleep, and before + dispatching any event sources. The <parameter>event</parameter> + parameter takes the even loop object to retrieve the timestamp + from. The <parameter>clock</parameter> parameter specifies the clock to + retrieve the timestamp for, and is one of + <constant>CLOCK_REALTIME</constant> (or its equivalent + <constant>CLOCK_REALTIME_ALARM</constant>), + <constant>CLOCK_MONOTONIC</constant> or + <constant>CLOCK_BOOTTIME</constant> (or its equivalent + <constant>CLOCK_BOOTTIME_ALARM</constant>), see <citerefentry + project='man-pages'><refentrytitle>clock_gettime</refentrytitle><manvolnum>2</manvolnum></citerefentry> + for more information on the various clocks. The retrieved + timestamp is stored in the <parameter>usec</parameter> parameter, + in µs since the clock's epoch. If this function is invoked before + the first event loop iteration the current time is returned, as + reported by <function>clock_gettime()</function>. To distinguish + this case from a regular invocation the return value will be + positive non-zero in this case, while it is zero when the returned + timestamp refers to the actual event loop iteration.</para> + </refsect1> + + <refsect1> + <title>Return Value</title> + + <para>If the first event loop iteration has not run yet + <function>sd_event_now()</function> returns the requested + timestamp in <parameter>usec</parameter> and returns a positive, + non-zero return value. Otherwise, on success it will return the + iteration's timestamp in <parameter>usec</parameter> and 0 as + return value. On failure, the call returns a negative errno-style + error code.</para> + </refsect1> + + <refsect1> + <title>Errors</title> + + <para>Returned errors may indicate the following problems:</para> + + <variablelist> + <varlistentry> + <term><constant>-EINVAL</constant></term> + + <listitem><para>An invalid parameter was + passed.</para></listitem> + + </varlistentry> + + <varlistentry> + <term><constant>-ECHILD</constant></term> + + <listitem><para>The event loop object was created in a + different process.</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_add_time</refentrytitle><manvolnum>3</manvolnum></citerefentry>, + <citerefentry project='man-pages'><refentrytitle>clock_gettime</refentrytitle><manvolnum>2</manvolnum></citerefentry> + </para> + </refsect1> + +</refentry> diff --git a/man/sd_event_run.xml b/man/sd_event_run.xml index 06236fcd1a..5b68959165 100644 --- a/man/sd_event_run.xml +++ b/man/sd_event_run.xml @@ -21,7 +21,7 @@ along with systemd; If not, see <http://www.gnu.org/licenses/>. --> -<refentry id="sd_event_run"> +<refentry id="sd_event_run" xmlns:xi="http://www.w3.org/2001/XInclude"> <refentryinfo> <title>sd_event_run</title> @@ -46,7 +46,7 @@ <refname>sd_event_run</refname> <refname>sd_event_loop</refname> - <refpurpose>Run the libsystemd event loop</refpurpose> + <refpurpose>Run an event loop</refpurpose> </refnamediv> <refsynopsisdiv> @@ -56,7 +56,7 @@ <funcprototype> <funcdef>int <function>sd_event_run</function></funcdef> <paramdef>sd_event *<parameter>event</parameter></paramdef> - <paramdef>uint64_t <parameter>timeout</parameter></paramdef> + <paramdef>uint64_t <parameter>usec</parameter></paramdef> </funcprototype> <funcprototype> @@ -69,47 +69,60 @@ <refsect1> <title>Description</title> - <para><function>sd_event_run()</function> can be used to run one - iteration of the event loop of libsystemd. This function waits - until an event to process is available, and dispatches a handler - for it. The <parameter>timeout</parameter> parameter specifices the - maximum time (in microseconds) to wait. <constant>(uint64_t) - -1</constant> may be used to specify an infinite timeout.</para> - - <para><function>sd_event_loop</function> runs - <function>sd_event_wait</function> in a loop with a timeout of - infinity. This makes it suitable for the main event loop of a - program.</para> + <para><function>sd_event_run()</function> may be used to run a single + iteration of the event loop specified in the + <parameter>event</parameter> parameter. The function waits until an event to + process is available, and dispatches the registered handler for + it. The <parameter>usec</parameter> parameter specifies the + maximum time (in microseconds) to wait for an event. Use + <constant>(uint64_t) -1</constant> to specify an infinite + timeout.</para> + + <para><function>sd_event_loop()</function> invokes + <function>sd_event_run()</function> in a loop, thus implementing + the actual event loop. The call returns as soon as exiting was + requested using + <citerefentry><refentrytitle>sd_event_exit</refentrytitle><manvolnum>3</manvolnum></citerefentry>.</para> <para>The event loop object <parameter>event</parameter> is created with - <function>sd_event_new</function>. - Events to wait for and their handlers can be registered with - <function>sd_event_add_time</function>, - <function>sd_event_add_child</function>, - <function>sd_event_add_signal</function>, - <function>sd_event_add_defer</function>, - <function>sd_event_add_exit</function>, + <citerefentry><refentrytitle>sd_event_new</refentrytitle><manvolnum>3</manvolnum></citerefentry>. + Events sources to wait for and their handlers may be registered + with + <citerefentry><refentrytitle>sd_event_add_io</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_add_post</refentrytitle><manvolnum>3</manvolnum></citerefentry> and - <function>sd_event_add_post</function>. + <citerefentry><refentrytitle>sd_event_add_exit</refentrytitle><manvolnum>3</manvolnum></citerefentry>. </para> - <para>For more fine-grained control, - <function>sd_event_prepare</function>, - <function>sd_event_wait</function>, and - <function>sd_event_dispatch</function> may be used. Along with - <function>sd_event_get_fd</function>, those functions make it - possible to integrate the libsystemd loop inside of another event - loop.</para> + <para>For low-level control of event loop execution, use + <citerefentry><refentrytitle>sd_event_prepare</refentrytitle><manvolnum>3</manvolnum></citerefentry>, + <citerefentry><refentrytitle>sd_event_wait</refentrytitle><manvolnum>3</manvolnum></citerefentry> + and + <citerefentry><refentrytitle>sd_event_dispatch</refentrytitle><manvolnum>3</manvolnum></citerefentry> + which are wrapped by <function>sd_event_run()</function>. Along + with + <citerefentry><refentrytitle>sd_event_get_fd</refentrytitle><manvolnum>3</manvolnum></citerefentry>, + these functions allow integration of an + <citerefentry><refentrytitle>sd-event</refentrytitle><manvolnum>3</manvolnum></citerefentry> + event loop into foreign event loop implementations.</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. - <function>sd_event_run</function> returns 0 if the event loop is - finished, and a positive value if it can be continued.</para> + <para>On failure, these functions return a negative errno-style + error code. <function>sd_event_run()</function> returns a + positive, non-zero integer if an event source was dispatched, and + zero when the specified timeout hit before an event source has + seen any event, and hence no event source was + dispatched. <function>sd_event_loop()</function> returns the exit + code specified when invoking + <function>sd_event_exit()</function>.</para> </refsect1> <refsect1> @@ -122,7 +135,7 @@ <term><constant>-EINVAL</constant></term> <listitem><para>The <parameter>event</parameter> parameter is - <constant>NULL</constant>.</para></listitem> + invalid or <constant>NULL</constant>.</para></listitem> </varlistentry> <varlistentry> @@ -153,15 +166,7 @@ <para>Other errors are possible, too.</para> </refsect1> - <refsect1> - <title>Notes</title> - - <para><function>sd_event_run()</function> and - <function>sd_event_loop()</function> are available - as a shared library, which can be compiled and linked to with the - <constant>libsystemd</constant> <citerefentry project='die-net'><refentrytitle>pkg-config</refentrytitle><manvolnum>1</manvolnum></citerefentry> - file.</para> - </refsect1> + <xi:include href="libsystemd-pkgconfig.xml" /> <refsect1> <title>See Also</title> @@ -169,13 +174,15 @@ <para> <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>, <citerefentry><refentrytitle>sd_event_new</refentrytitle><manvolnum>3</manvolnum></citerefentry>, - <citerefentry><refentrytitle>sd_event_wait</refentrytitle><manvolnum>3</manvolnum></citerefentry>, <citerefentry><refentrytitle>sd_event_add_io</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_defer</refentrytitle><manvolnum>3</manvolnum></citerefentry>, <citerefentry><refentrytitle>sd_event_add_exit</refentrytitle><manvolnum>3</manvolnum></citerefentry>, <citerefentry><refentrytitle>sd_event_add_post</refentrytitle><manvolnum>3</manvolnum></citerefentry>, + <citerefentry><refentrytitle>sd_event_exit</refentrytitle><manvolnum>3</manvolnum></citerefentry>, + <citerefentry><refentrytitle>sd_event_get_fd</refentrytitle><manvolnum>3</manvolnum></citerefentry>, + <citerefentry><refentrytitle>sd_event_wait</refentrytitle><manvolnum>3</manvolnum></citerefentry>, <ulink url="https://developer.gnome.org/glib/unstable/glib-The-Main-Event-Loop.html">GLib Main Event Loop</ulink>. </para> </refsect1> diff --git a/man/sd_event_set_name.xml b/man/sd_event_set_name.xml deleted file mode 100644 index 1471e12e59..0000000000 --- a/man/sd_event_set_name.xml +++ /dev/null @@ -1,151 +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 2014 Zbigniew Jędrzejewski-Szmek - - 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_set_name" - xmlns:xi="http://www.w3.org/2001/XInclude"> - - <refentryinfo> - <title>sd_event_set_name</title> - <productname>systemd</productname> - - <authorgroup> - <author> - <contrib>More text</contrib> - <firstname>Zbigniew</firstname> - <surname>Jędrzejewski-Szmek</surname> - <email>zbyszek@in.waw.pl</email> - </author> - </authorgroup> - </refentryinfo> - - <refmeta> - <refentrytitle>sd_event_set_name</refentrytitle> - <manvolnum>3</manvolnum> - </refmeta> - - <refnamediv> - <refname>sd_event_set_name</refname> - <refname>sd_event_get_name</refname> - - <refpurpose>Set human-readable names for event sources</refpurpose> - </refnamediv> - - <refsynopsisdiv> - <funcsynopsis> - <funcsynopsisinfo>#include <systemd/sd-bus.h></funcsynopsisinfo> - - <funcprototype> - <funcdef>int <function>sd_event_set_name</function></funcdef> - <paramdef>sd_event_source *<parameter>source</parameter></paramdef> - <paramdef>const char *<parameter>name</parameter></paramdef> - </funcprototype> - - <funcprototype> - <funcdef>int <function>sd_event_get_name</function></funcdef> - <paramdef>sd_event_source *<parameter>source</parameter></paramdef> - <paramdef>const char **<parameter>name</parameter></paramdef> - </funcprototype> - - </funcsynopsis> - </refsynopsisdiv> - - <refsect1> - <title>Description</title> - - <para><function>sd_event_set_name()</function> can be used to set - an arbitrary name for the event source - <parameter>source</parameter>. This name will be used in error - messages generated by - <citerefentry><refentrytitle>sd-event</refentrytitle><manvolnum>3</manvolnum></citerefentry> - for this source. The <parameter>name</parameter> must point - to a <constant>NUL</constant>-terminated string or be - <constant>NULL</constant>. In the latter case, the name will be - unset. The string is copied internally, so the - <parameter>name</parameter> argument is not referenced after the - function returns.</para> - - <para><function>sd_event_set_name()</function> can be used to - query the current name assigned to source - <parameter>source</parameter>. It returns a pointer to the current - name (possibly <constant>NULL</constant>) in - <parameter>name</parameter>.</para> - </refsect1> - - <refsect1> - <title>Return Value</title> - - <para>On success, <function>sd_event_set_name()</function> and - <function>sd_event_get_name()</function> return a - non-negative integer. On failure, they return a negative - errno-style error code.</para> - </refsect1> - - <refsect1> - <title>Errors</title> - - <para>Returned errors may indicate the following problems:</para> - - <variablelist> - <varlistentry> - <term><constant>-EINVAL</constant></term> - - <listitem><para><parameter>source</parameter> is not a valid - pointer to an <structname>sd_event_source</structname> - structure or the <parameter>name</parameter> argument for - <function>sd_event_get_name()</function> is - <constant>NULL</constant>.</para></listitem> - </varlistentry> - - <varlistentry> - <term><constant>-ENOMEM</constant></term> - - <listitem><para>Not enough memory to copy the - name.</para></listitem> - </varlistentry> - </variablelist> - </refsect1> - - <refsect1> - <title>Notes</title> - - <para>The functions described here are available as a - shared library, which can be compiled and linked to with the - <constant>libsystemd</constant> <citerefentry - project='die-net'><refentrytitle>pkg-config</refentrytitle><manvolnum>1</manvolnum></citerefentry> - file.</para> - </refsect1> - - <refsect1> - <title>See Also</title> - - <para> - <citerefentry><refentrytitle>sd-event</refentrytitle><manvolnum>3</manvolnum></citerefentry>, - <citerefentry><refentrytitle>sd_event_add_time</refentrytitle><manvolnum>3</manvolnum></citerefentry>, - <citerefentry><refentrytitle>sd_event_add_child</refentrytitle><manvolnum>3</manvolnum></citerefentry>, - <citerefentry><refentrytitle>sd_event_add_signal</refentrytitle><manvolnum>3</manvolnum></citerefentry>, - <citerefentry><refentrytitle>sd_event_add_defer</refentrytitle><manvolnum>3</manvolnum></citerefentry>, - <citerefentry><refentrytitle>sd_event_run</refentrytitle><manvolnum>3</manvolnum></citerefentry> - </para> - </refsect1> - -</refentry> diff --git a/man/sd_event_set_watchdog.xml b/man/sd_event_set_watchdog.xml new file mode 100644 index 0000000000..cbc5bc0836 --- /dev/null +++ b/man/sd_event_set_watchdog.xml @@ -0,0 +1,177 @@ +<?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_set_watchdog" xmlns:xi="http://www.w3.org/2001/XInclude"> + + <refentryinfo> + <title>sd_event_set_watchdog</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_set_watchdog</refentrytitle> + <manvolnum>3</manvolnum> + </refmeta> + + <refnamediv> + <refname>sd_event_set_watchdog</refname> + <refname>sd_event_get_watchdog</refname> + + <refpurpose>Enable event loop watchdog support</refpurpose> + </refnamediv> + + <refsynopsisdiv> + <funcsynopsis> + <funcsynopsisinfo>#include <systemd/sd-event.h></funcsynopsisinfo> + + <funcprototype> + <funcdef>int <function>sd_event_set_watchdog</function></funcdef> + <paramdef>sd_event *<parameter>event</parameter></paramdef> + <paramdef>int b</paramdef> + </funcprototype> + + <funcprototype> + <funcdef>int <function>sd_event_get_watchdog</function></funcdef> + <paramdef>sd_event *<parameter>event</parameter></paramdef> + </funcprototype> + + </funcsynopsis> + </refsynopsisdiv> + + <refsect1> + <title>Description</title> + + <para><function>sd_event_set_watchdog()</function> may be used to + enable or disable automatic watchdog notification support in the + event loop object specified in the <parameter>event</parameter> + parameter. Specifically, depending on the <parameter>b</parameter> + boolean argument this will make sure the event loop wakes up in + regular intervals and sends watchdog notification messages to the + service manager, if this was requested by the service + manager. Watchdog support is determined with + <citerefentry><refentrytitle>sd_watchdog_enabled</refentrytitle><manvolnum>3</manvolnum></citerefentry>, + and watchdog messages are sent with + <citerefentry><refentrytitle>sd_notify</refentrytitle><manvolnum>3</manvolnum></citerefentry>. See + the <varname>WatchdogSec=</varname> setting in + <citerefentry><refentrytitle>systemd.service</refentrytitle><manvolnum>5</manvolnum></citerefentry> + for details on how to enable watchdog support for a service and + the protocol used. The wake-up interval is chosen as half the + watchdog timeout declared by the service manager via the + <varname>$WATCHDOG_USEC</varname> environment variable. If the + service manager did not request watchdog notifications, or if the + process was not invoked by the service manager this call with a + true <parameter>b</parameter> parameter executes no + operation. Passing a false <parameter>b</parameter> parameter will + disable the automatic sending of watchdog notification messages if + it was enabled before. Newly allocated event loop objects have + this feature disabled.</para> + + <para>The first watchdog notification message is sent immediately + when <function>set_event_set_watchdog()</function> is invoked with + a true <parameter>b</parameter> parameter.</para> + + <para>The watchdog logic is designed to allow the service manager + to automatically detect services that ceased processing of + incoming events, and thus appear "hung". Watchdog notifications + are sent out only at the beginning of each event loop + iteration. If an event source dispatch function blocks for an + excessively long time and does not return execution to the event + loop quickly, this might hence cause the notification message to + be delayed, and possibly result in abnormal program termination, + as configured in the service unit file.</para> + + <para><function>sd_event_get_watchdog()</function> may be used to + determine whether watchdog support was previously requested by a + call to <function>sd_event_set_watchdog()</function> with a true + <parameter>b</parameter> parameter and successfully + enabled.</para> + </refsect1> + + <refsect1> + <title>Return Value</title> + + <para>On success, <function>sd_event_set_watchdog()</function> and + <function>sd_event_get_watchdog()</function> return a non-zero + positive integer if the service manager requested watchdog support + and watchdog support was successfully enabled. They return zero if + the service manager did not request watchdog support, or if + watchdog support was explicitly disabled with a false + <parameter>b</parameter> parameter. On failure, they return a + negative errno-style error + code.</para> + </refsect1> + + <refsect1> + <title>Errors</title> + + <para>Returned errors may indicate the following problems:</para> + + <variablelist> + + <varlistentry> + <term><constant>-ECHILD</constant></term> + + <listitem><para>The event loop has been created in a different process.</para></listitem> + </varlistentry> + + <varlistentry> + <term><constant>-EINVAL</constant></term> + + <listitem><para>The passed event loop object was invalid.</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_add_io</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_add_post</refentrytitle><manvolnum>3</manvolnum></citerefentry>, + <citerefentry><refentrytitle>sd_event_add_exit</refentrytitle><manvolnum>3</manvolnum></citerefentry>, + <citerefentry><refentrytitle>sd_watchdog_enabled</refentrytitle><manvolnum>3</manvolnum></citerefentry>, + <citerefentry><refentrytitle>sd_notify</refentrytitle><manvolnum>3</manvolnum></citerefentry>, + <citerefentry><refentrytitle>systemd.service</refentrytitle><manvolnum>5</manvolnum></citerefentry> + </para> + </refsect1> + +</refentry> diff --git a/man/sd_event_source_get_event.xml b/man/sd_event_source_get_event.xml new file mode 100644 index 0000000000..2fdbd411bd --- /dev/null +++ b/man/sd_event_source_get_event.xml @@ -0,0 +1,100 @@ +<?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_source_get_event" xmlns:xi="http://www.w3.org/2001/XInclude"> + + <refentryinfo> + <title>sd_event_source_get_event</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_source_get_event</refentrytitle> + <manvolnum>3</manvolnum> + </refmeta> + + <refnamediv> + <refname>sd_event_source_get_event</refname> + + <refpurpose>Retrieve the event loop of an event source</refpurpose> + </refnamediv> + + <refsynopsisdiv> + <funcsynopsis> + <funcsynopsisinfo>#include <systemd/sd-event.h></funcsynopsisinfo> + + <funcprototype> + <funcdef>sd_event* <function>sd_event_source_get_event</function></funcdef> + <paramdef>sd_event_source *<parameter>source</parameter></paramdef> + </funcprototype> + + </funcsynopsis> + </refsynopsisdiv> + + <refsect1> + <title>Description</title> + + <para><function>sd_event_source_get_event()</function> may be used + to retrieve the event loop object the event source object specified + as <parameter>source</parameter> is associated with. The event + loop object is specified when creating an event source object with + calls such as + <citerefentry><refentrytitle>sd_event_add_io</refentrytitle><manvolnum>3</manvolnum></citerefentry> + or + <citerefentry><refentrytitle>sd_event_add_time</refentrytitle><manvolnum>3</manvolnum></citerefentry>.</para> + </refsect1> + + <refsect1> + <title>Return Value</title> + + <para>On success, <function>sd_event_source_get_event()</function> + returns the associated event loop object. On failure, it returns + NULL.</para> + </refsect1> + + <xi:include href="libsystemd-pkgconfig.xml" /> + + <refsect1> + <title>See Also</title> + + <para> + <citerefentry><refentrytitle>sd-event</refentrytitle><manvolnum>3</manvolnum></citerefentry>, + <citerefentry><refentrytitle>sd_event_add_io</refentrytitle><manvolnum>3</manvolnum></citerefentry>, + <citerefentry><refentrytitle>sd_event_add_time</refentrytitle><manvolnum>3</manvolnum></citerefentry>, + <citerefentry><refentrytitle>sd_event_add_child</refentrytitle><manvolnum>3</manvolnum></citerefentry>, + <citerefentry><refentrytitle>sd_event_add_signal</refentrytitle><manvolnum>3</manvolnum></citerefentry>, + <citerefentry><refentrytitle>sd_event_add_defer</refentrytitle><manvolnum>3</manvolnum></citerefentry>, + <citerefentry><refentrytitle>sd_event_source_set_userdata</refentrytitle><manvolnum>3</manvolnum></citerefentry> + </para> + </refsect1> + +</refentry> diff --git a/man/sd_event_source_get_pending.xml b/man/sd_event_source_get_pending.xml new file mode 100644 index 0000000000..1c06e81fe0 --- /dev/null +++ b/man/sd_event_source_get_pending.xml @@ -0,0 +1,167 @@ +<?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_source_get_pending" xmlns:xi="http://www.w3.org/2001/XInclude"> + + <refentryinfo> + <title>sd_event_source_get_pending</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_source_get_pending</refentrytitle> + <manvolnum>3</manvolnum> + </refmeta> + + <refnamediv> + <refname>sd_event_source_get_pending</refname> + + <refpurpose>Determine pending state of event sources</refpurpose> + </refnamediv> + + <refsynopsisdiv> + <funcsynopsis> + <funcsynopsisinfo>#include <systemd/sd-event.h></funcsynopsisinfo> + + <funcprototype> + <funcdef>int <function>sd_event_source_get_pending</function></funcdef> + <paramdef>sd_event_source *<parameter>source</parameter></paramdef> + </funcprototype> + + </funcsynopsis> + </refsynopsisdiv> + + <refsect1> + <title>Description</title> + + <para><function>sd_event_source_get_pending()</function> may be + used to determine whether the event source object specified as + <parameter>source</parameter> has seen events but has not been + dispatched yet (and thus is marked "pending").</para> + + <para>Event source objects initially are not marked pending, when + they are created with calls such as + <citerefentry><refentrytitle>sd_event_add_io</refentrytitle><manvolnum>3</manvolnum></citerefentry>, + <citerefentry><refentrytitle>sd_event_add_time</refentrytitle><manvolnum>3</manvolnum></citerefentry>, + with the exception of those created with + <citerefentry><refentrytitle>sd_event_add_defer</refentrytitle><manvolnum>3</manvolnum></citerefentry> + which are immediately marked pending, and + <citerefentry><refentrytitle>sd_event_add_exit</refentrytitle><manvolnum>3</manvolnum></citerefentry> + for which the "pending" concept is not defined. For details see + the respective manual pages.</para> + + <para>In each event loop iteration one event source of those + marked pending is dispatched, in the order defined by the event + source priority, as set with + <citerefentry><refentrytitle>sd_event_source_set_priority</refentrytitle><manvolnum>3</manvolnum></citerefentry>.</para> + + <para>For I/O event sources, as created with + <citerefentry><refentrytitle>sd_event_add_io</refentrytitle><manvolnum>3</manvolnum></citerefentry>, + the call + <citerefentry><refentrytitle>sd_event_get_io_revents</refentrytitle><manvolnum>3</manvolnum></citerefentry> + may be used to query the type of event pending in more + detail.</para> + + </refsect1> + + <refsect1> + <title>Return Value</title> + + <para>On success, + <function>sd_event_source_get_pending()</function> returns an + integer greater than zero when the event source is marked pending, + and zero when the event source is not marked pending. On failure, + it returns a negative errno-style error code.</para> + </refsect1> + + <refsect1> + <title>Errors</title> + + <para>Returned errors may indicate the following problems:</para> + + <variablelist> + <varlistentry> + <term><constant>-EINVAL</constant></term> + + <listitem><para><parameter>source</parameter> is not a valid + pointer to an <structname>sd_event_source</structname> + object.</para></listitem> + </varlistentry> + + <varlistentry> + <term><constant>-EDOM</constant></term> + + <listitem><para><parameter>source</parameter> refers to an + event source object created with + <citerefentry><refentrytitle>sd_event_add_exit</refentrytitle><manvolnum>3</manvolnum></citerefentry>.</para></listitem> + </varlistentry> + + <varlistentry> + <term><constant>-ENOMEM</constant></term> + + <listitem><para>Not enough memory.</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> + + </variablelist> + </refsect1> + + <xi:include href="libsystemd-pkgconfig.xml" /> + + <refsect1> + <title>See Also</title> + + <para> + <citerefentry><refentrytitle>sd-event</refentrytitle><manvolnum>3</manvolnum></citerefentry>, + <citerefentry><refentrytitle>sd_event_add_io</refentrytitle><manvolnum>3</manvolnum></citerefentry>, + <citerefentry><refentrytitle>sd_event_add_time</refentrytitle><manvolnum>3</manvolnum></citerefentry>, + <citerefentry><refentrytitle>sd_event_add_child</refentrytitle><manvolnum>3</manvolnum></citerefentry>, + <citerefentry><refentrytitle>sd_event_add_signal</refentrytitle><manvolnum>3</manvolnum></citerefentry>, + <citerefentry><refentrytitle>sd_event_add_defer</refentrytitle><manvolnum>3</manvolnum></citerefentry>, + <citerefentry><refentrytitle>sd_event_source_unref</refentrytitle><manvolnum>3</manvolnum></citerefentry> + </para> + </refsect1> + +</refentry> diff --git a/man/sd_event_source_set_description.xml b/man/sd_event_source_set_description.xml new file mode 100644 index 0000000000..b9488a622f --- /dev/null +++ b/man/sd_event_source_set_description.xml @@ -0,0 +1,170 @@ +<?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 2014 Zbigniew Jędrzejewski-Szmek + + 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_source_set_description" xmlns:xi="http://www.w3.org/2001/XInclude"> + + <refentryinfo> + <title>sd_event_source_set_description</title> + <productname>systemd</productname> + + <authorgroup> + <author> + <contrib>More text</contrib> + <firstname>Zbigniew</firstname> + <surname>Jędrzejewski-Szmek</surname> + <email>zbyszek@in.waw.pl</email> + </author> + </authorgroup> + </refentryinfo> + + <refmeta> + <refentrytitle>sd_event_source_set_description</refentrytitle> + <manvolnum>3</manvolnum> + </refmeta> + + <refnamediv> + <refname>sd_event_source_set_description</refname> + <refname>sd_event_source_get_description</refname> + + <refpurpose>Set or retrieve descriptive names of event sources</refpurpose> + </refnamediv> + + <refsynopsisdiv> + <funcsynopsis> + <funcsynopsisinfo>#include <systemd/sd-event.h></funcsynopsisinfo> + + <funcprototype> + <funcdef>int <function>sd_event_source_set_description</function></funcdef> + <paramdef>sd_event_source *<parameter>source</parameter></paramdef> + <paramdef>const char *<parameter>description</parameter></paramdef> + </funcprototype> + + <funcprototype> + <funcdef>int <function>sd_event_source_get_description</function></funcdef> + <paramdef>sd_event_source *<parameter>source</parameter></paramdef> + <paramdef>const char **<parameter>description</parameter></paramdef> + </funcprototype> + + </funcsynopsis> + </refsynopsisdiv> + + <refsect1> + <title>Description</title> + + <para><function>sd_event_source_set_description()</function> may + be used to set an arbitrary descriptive name for the event source + object specified as <parameter>source</parameter>. This name will + be used in debugging messages generated by + <citerefentry><refentrytitle>sd-event</refentrytitle><manvolnum>3</manvolnum></citerefentry> + for this event source, and may be queried using + <function>sd_event_source_get_description()</function> for + debugging purposes. The <parameter>description</parameter> parameter shall + point to a <constant>NUL</constant>-terminated string or be + <constant>NULL</constant>. In the latter case, the descriptive + name will be unset. The string is copied internally, hence the + <parameter>description</parameter> argument is not referenced + after the function returns.</para> + + <para><function>sd_event_source_get_description()</function> may + be used to query the current descriptive name assigned to the + event source object <parameter>source</parameter>. It returns a + pointer to the current name in <parameter>description</parameter>, + stored in memory internal to the event source. The memory is + invalidated when the event source is destroyed or the descriptive + name is changed.</para> + + <para>Event source objects generally have no description set when + they are created, except for UNIX signal event sources created + with + <citerefentry><refentrytitle>sd_event_add_signal</refentrytitle><manvolnum>3</manvolnum></citerefentry>, + whose descriptive name is initialized to the signal's C constant + name (e.g. <literal>SIGINT</literal> or + <literal>SIGTERM</literal>).</para> + </refsect1> + + <refsect1> + <title>Return Value</title> + + <para>On success, <function>sd_event_source_set_description()</function> and + <function>sd_event_source_get_description()</function> return a + non-negative integer. On failure, they return a negative + errno-style error code.</para> + </refsect1> + + <refsect1> + <title>Errors</title> + + <para>Returned errors may indicate the following problems:</para> + + <variablelist> + <varlistentry> + <term><constant>-EINVAL</constant></term> + + <listitem><para><parameter>source</parameter> is not a valid + pointer to an <structname>sd_event_source</structname> + object or the <parameter>description</parameter> argument for + <function>sd_event_source_get_description()</function> is + <constant>NULL</constant>.</para></listitem> + </varlistentry> + + <varlistentry> + <term><constant>-ENOMEM</constant></term> + + <listitem><para>Not enough memory to copy the + name.</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>-ENXIO</constant></term> + + <listitem><para>No name was set for the event + source.</para></listitem> + </varlistentry> + + </variablelist> + </refsect1> + + <xi:include href="libsystemd-pkgconfig.xml" /> + + <refsect1> + <title>See Also</title> + + <para> + <citerefentry><refentrytitle>sd-event</refentrytitle><manvolnum>3</manvolnum></citerefentry>, + <citerefentry><refentrytitle>sd_event_add_io</refentrytitle><manvolnum>3</manvolnum></citerefentry>, + <citerefentry><refentrytitle>sd_event_add_time</refentrytitle><manvolnum>3</manvolnum></citerefentry>, + <citerefentry><refentrytitle>sd_event_add_child</refentrytitle><manvolnum>3</manvolnum></citerefentry>, + <citerefentry><refentrytitle>sd_event_add_signal</refentrytitle><manvolnum>3</manvolnum></citerefentry>, + <citerefentry><refentrytitle>sd_event_add_defer</refentrytitle><manvolnum>3</manvolnum></citerefentry>, + <citerefentry><refentrytitle>sd_event_source_set_userdata</refentrytitle><manvolnum>3</manvolnum></citerefentry> + </para> + </refsect1> + +</refentry> diff --git a/man/sd_event_source_set_enabled.xml b/man/sd_event_source_set_enabled.xml new file mode 100644 index 0000000000..74c02e87bb --- /dev/null +++ b/man/sd_event_source_set_enabled.xml @@ -0,0 +1,179 @@ +<?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_source_set_enabled" xmlns:xi="http://www.w3.org/2001/XInclude"> + + <refentryinfo> + <title>sd_event_source_set_enabled</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_source_set_enabled</refentrytitle> + <manvolnum>3</manvolnum> + </refmeta> + + <refnamediv> + <refname>sd_event_source_set_enabled</refname> + <refname>sd_event_source_get_enabled</refname> + <refname>SD_EVENT_ON</refname> + <refname>SD_EVENT_OFF</refname> + <refname>SD_EVENT_ONESHOT</refname> + + <refpurpose>Enable or disable event sources</refpurpose> + </refnamediv> + + <refsynopsisdiv> + <funcsynopsis> + <funcsynopsisinfo>#include <systemd/sd-event.h></funcsynopsisinfo> + + <funcsynopsisinfo><token>enum</token> { + <constant>SD_EVENT_OFF</constant> = 0, + <constant>SD_EVENT_ON</constant> = 1, + <constant>SD_EVENT_ONESHOT</constant> = -1, +};</funcsynopsisinfo> + + <funcprototype> + <funcdef>int <function>sd_event_source_set_enabled</function></funcdef> + <paramdef>sd_event_source *<parameter>source</parameter></paramdef> + <paramdef>int <parameter>enabled</parameter></paramdef> + </funcprototype> + + <funcprototype> + <funcdef>int <function>sd_event_source_get_enabled</function></funcdef> + <paramdef>sd_event_source *<parameter>source</parameter></paramdef> + <paramdef>int *<parameter>enabled</parameter></paramdef> + </funcprototype> + + </funcsynopsis> + </refsynopsisdiv> + + <refsect1> + <title>Description</title> + + <para><function>sd_event_source_set_enabled()</function> may be + used to enable or disable the event source object specified as + <parameter>source</parameter>. The <parameter>enabled</parameter> + parameter takes one of <constant>SD_EVENT_ON</constant> (to + enable), <constant>SD_EVENT_OFF</constant> (to disable) or + <constant>SD_EVENT_ONESHOT</constant>. If invoked with + <constant>SD_EVENT_ONESHOT</constant> the event source will be + enabled but automatically reset to + <constant>SD_EVENT_OFF</constant> after the event source was + dispatched once.</para> + + <para>Event sources that are disabled will not result in event + loop wakeups and will not be dispatched, until they are enabled + again.</para> + + <para><function>sd_event_source_get_enabled()</function> may be + used to query whether the event source object + <parameter>source</parameter> is currently enabled or not. It + returns the enablement state in + <parameter>enabled</parameter>.</para> + + <para>Event source objects are enabled when they are first created + with calls such as + <citerefentry><refentrytitle>sd_event_add_io</refentrytitle><manvolnum>3</manvolnum></citerefentry>, + <citerefentry><refentrytitle>sd_event_add_time</refentrytitle><manvolnum>3</manvolnum></citerefentry>. However, + depending on the event source type they are enabled continously + (<constant>SD_EVENT_ON</constant>) or only for a single invocation + of the event source handler + (<constant>SD_EVENT_ONESHOT</constant>). For details see the + respective manual pages.</para> + + <para>As event source objects stay active and may be dispatched as + long as there is at least one reference to them, in many cases it + is a good idea to combine a call to + <citerefentry><refentrytitle>sd_event_source_unref</refentrytitle><manvolnum>3</manvolnum></citerefentry> + with a prior call to + <function>sd_event_source_set_enabled()</function> with + <constant>SD_EVENT_OFF</constant>, to ensure the event source is + not dispatched again until all other remaining references are dropped.</para> + </refsect1> + + <refsect1> + <title>Return Value</title> + + <para>On success, <function>sd_event_source_set_enabled()</function> and + <function>sd_event_source_get_enabled()</function> return a + non-negative integer. On failure, they return a negative + errno-style error code.</para> + </refsect1> + + <refsect1> + <title>Errors</title> + + <para>Returned errors may indicate the following problems:</para> + + <variablelist> + <varlistentry> + <term><constant>-EINVAL</constant></term> + + <listitem><para><parameter>source</parameter> is not a valid + pointer to an <structname>sd_event_source</structname> + object.</para></listitem> + </varlistentry> + + <varlistentry> + <term><constant>-ENOMEM</constant></term> + + <listitem><para>Not enough memory.</para></listitem> + </varlistentry> + + <varlistentry> + <term><constant>-ECHILD</constant></term> + + <listitem><para>The event loop has been created in a different process.</para></listitem> + + </varlistentry> + + </variablelist> + </refsect1> + + <xi:include href="libsystemd-pkgconfig.xml" /> + + <refsect1> + <title>See Also</title> + + <para> + <citerefentry><refentrytitle>sd-event</refentrytitle><manvolnum>3</manvolnum></citerefentry>, + <citerefentry><refentrytitle>sd_event_add_io</refentrytitle><manvolnum>3</manvolnum></citerefentry>, + <citerefentry><refentrytitle>sd_event_add_time</refentrytitle><manvolnum>3</manvolnum></citerefentry>, + <citerefentry><refentrytitle>sd_event_add_child</refentrytitle><manvolnum>3</manvolnum></citerefentry>, + <citerefentry><refentrytitle>sd_event_add_signal</refentrytitle><manvolnum>3</manvolnum></citerefentry>, + <citerefentry><refentrytitle>sd_event_add_defer</refentrytitle><manvolnum>3</manvolnum></citerefentry>, + <citerefentry><refentrytitle>sd_event_source_unref</refentrytitle><manvolnum>3</manvolnum></citerefentry> + </para> + </refsect1> + +</refentry> diff --git a/man/sd_event_source_set_prepare.xml b/man/sd_event_source_set_prepare.xml new file mode 100644 index 0000000000..7066a55306 --- /dev/null +++ b/man/sd_event_source_set_prepare.xml @@ -0,0 +1,171 @@ +<?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_source_set_prepare" xmlns:xi="http://www.w3.org/2001/XInclude"> + + <refentryinfo> + <title>sd_event_source_set_prepare</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_source_set_prepare</refentrytitle> + <manvolnum>3</manvolnum> + </refmeta> + + <refnamediv> + <refname>sd_event_source_set_prepare</refname> + + <refpurpose>Set a preparation callback for event sources</refpurpose> + </refnamediv> + + <refsynopsisdiv> + <funcsynopsis> + <funcsynopsisinfo>#include <systemd/sd-event.h></funcsynopsisinfo> + + <funcprototype> + <funcdef>int <function>sd_event_source_set_prepare</function></funcdef> + <paramdef>sd_event_source *<parameter>source</parameter></paramdef> + <paramdef>sd_event_handler_t <parameter>callback</parameter></paramdef> + </funcprototype> + + <funcprototype> + <funcdef>typedef int (*<function>sd_event_handler_t</function>)</funcdef> + <paramdef>sd_event_source *<parameter>s</parameter></paramdef> + <paramdef>void *<parameter>userdata</parameter></paramdef> + </funcprototype> + + </funcsynopsis> + </refsynopsisdiv> + + <refsect1> + <title>Description</title> + + <para><function>sd_event_source_set_prepare()</function> may be + used to set a prepartion callback for the event source object + specified as <parameter>source</parameter>. The callback function + specified as <parameter>callback</parameter> will be invoked + immediately before the event loop goes to sleep to wait for + incoming events. It is invoked with the user data pointer passed + when the event source was created. The callback function may be + used to reconfigure the precise events to wait for. If the + <parameter>callback</parameter> parameter is passed as NULL the + callback function is reset. </para> + + <para>Event source objects have no preparation callback associated + when they are first created with calls such as + <citerefentry><refentrytitle>sd_event_add_io</refentrytitle><manvolnum>3</manvolnum></citerefentry>, + <citerefentry><refentrytitle>sd_event_add_time</refentrytitle><manvolnum>3</manvolnum></citerefentry>. Preparation + callback functions are supported for all event source types with + the exception of those created with + <citerefentry><refentrytitle>sd_event_add_exit</refentrytitle><manvolnum>3</manvolnum></citerefentry>. Preparation + callback functions are dispatched in the order indicated by the + event source's priority field, as set with + <citerefentry><refentrytitle>sd_event_source_set_priority</refentrytitle><manvolnum>3</manvolnum></citerefentry>. Preparation + callbacks of disabled event sources (see + <citerefentry><refentrytitle>sd_event_source_set_enabled</refentrytitle><manvolnum>3</manvolnum></citerefentry>) + are not invoked.</para> + </refsect1> + + <refsect1> + <title>Return Value</title> + + <para>On success, + <function>sd_event_source_set_prepare()</function> returns a + non-negative integer. On failure, it returns a negative + errno-style error code.</para> + </refsect1> + + <refsect1> + <title>Errors</title> + + <para>Returned errors may indicate the following problems:</para> + + <variablelist> + <varlistentry> + <term><constant>-EINVAL</constant></term> + + <listitem><para><parameter>source</parameter> is not a valid + pointer to an <structname>sd_event_source</structname> + object.</para></listitem> + </varlistentry> + + <varlistentry> + <term><constant>-ESTALE</constant></term> + + <listitem><para>The event loop is already terminated.</para></listitem> + + </varlistentry> + <varlistentry> + <term><constant>-ENOMEM</constant></term> + + <listitem><para>Not enough memory.</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 specified event source has been created + with + <citerefentry><refentrytitle>sd_event_add_exit</refentrytitle><manvolnum>3</manvolnum></citerefentry>.</para></listitem> + + </varlistentry> + + </variablelist> + </refsect1> + + <xi:include href="libsystemd-pkgconfig.xml" /> + + <refsect1> + <title>See Also</title> + + <para> + <citerefentry><refentrytitle>sd-event</refentrytitle><manvolnum>3</manvolnum></citerefentry>, + <citerefentry><refentrytitle>sd_event_add_io</refentrytitle><manvolnum>3</manvolnum></citerefentry>, + <citerefentry><refentrytitle>sd_event_add_time</refentrytitle><manvolnum>3</manvolnum></citerefentry>, + <citerefentry><refentrytitle>sd_event_add_child</refentrytitle><manvolnum>3</manvolnum></citerefentry>, + <citerefentry><refentrytitle>sd_event_add_signal</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> + </para> + </refsect1> + +</refentry> diff --git a/man/sd_event_source_set_priority.xml b/man/sd_event_source_set_priority.xml new file mode 100644 index 0000000000..cc0f5a0103 --- /dev/null +++ b/man/sd_event_source_set_priority.xml @@ -0,0 +1,189 @@ +<?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_source_set_priority" xmlns:xi="http://www.w3.org/2001/XInclude"> + + <refentryinfo> + <title>sd_event_source_set_priority</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_source_set_priority</refentrytitle> + <manvolnum>3</manvolnum> + </refmeta> + + <refnamediv> + <refname>sd_event_source_set_priority</refname> + <refname>sd_event_source_get_priority</refname> + <refname>SD_EVENT_PRIORITY_IMPORTANT</refname> + <refname>SD_EVENT_PRIORITY_NORMAL</refname> + <refname>SD_EVENT_PRIORITY_IDLE</refname> + + <refpurpose>Set or retrieve the priority of event sources</refpurpose> + </refnamediv> + + <refsynopsisdiv> + <funcsynopsis> + <funcsynopsisinfo>#include <systemd/sd-event.h></funcsynopsisinfo> + + <funcsynopsisinfo><token>enum</token> { + <constant>SD_EVENT_SOURCE_IMPORTANT</constant> = -100, + <constant>SD_EVENT_SOURCE_NORMAL</constant> = 0, + <constant>SD_EVENT_SOURCE_IDLE</constant> = 100, +};</funcsynopsisinfo> + + <funcprototype> + <funcdef>int <function>sd_event_source_set_priority</function></funcdef> + <paramdef>sd_event_source *<parameter>source</parameter></paramdef> + <paramdef>int64_t <parameter>priority</parameter></paramdef> + </funcprototype> + + <funcprototype> + <funcdef>int <function>sd_event_source_get_priority</function></funcdef> + <paramdef>sd_event_source *<parameter>source</parameter></paramdef> + <paramdef>int64_t *<parameter>priority</parameter></paramdef> + </funcprototype> + + </funcsynopsis> + </refsynopsisdiv> + + <refsect1> + <title>Description</title> + + <para><function>sd_event_source_set_priority()</function> may be + used to set the priority for the event source object specified as + <parameter>source</parameter>. The priority is specified as an + arbitrary signed 64bit integer. The priority is initialized to + <constant>SD_EVENT_PRIORITY_NORMAL</constant> (0) when the event + source is allocated with a call such as + <citerefentry><refentrytitle>sd_event_add_io</refentrytitle><manvolnum>3</manvolnum></citerefentry> + or + <citerefentry><refentrytitle>sd_event_add_time</refentrytitle><manvolnum>3</manvolnum></citerefentry>, + and may be changed with this call. If multiple event sources have seen events at the same time, they are dispatched in the order indicated by the + event sources' priorities. Event sources with smaller priority + values are dispatched first. As well-known points of reference, + the constants <constant>SD_EVENT_PRIORITY_IMPORTANT</constant> + (-100), <constant>SD_EVENT_PRIORITY_NORMAL</constant> (0) and + <constant>SD_EVENT_PRIORITY_IDLE</constant> (100) may be used to + indicate event sources that shall be dispatched early, normally or + late. It is recommended to specify priorities based on these + definitions, and relative to them -- however, the full 64bit + signed integer range is available for ordering event + sources.</para> + + <para>Priorities define the order in which event sources that have + seen events are dispatched. Care should be taken to ensure that + high-priority event sources (those with negative priority values + assigned) do not cause starvation of low-priority event sources + (those with positive priority values assigned).</para> + + <para>The order in which event sources with the same priority are + dispatched is undefined, but the event loop generally tries to + dispatch them in the order it learnt about events on them. As the + backing kernel primitives do not provide accurate information + about the order in which events occured this is not necessarily + reliable. However, it is guaranteed that if events are seen on + multiple same-priority event sources at the same time, each one is + not dispatched again until all others have been dispatched + once. This behaviour guarantees that within each priority + particular event sources do not starve or dominate the event + loop.</para> + + <para><function>sd_event_source_get_priority()</function> may be + used to query the current priority assigned to the event source + object <parameter>source</parameter>.</para> + </refsect1> + + <refsect1> + <title>Return Value</title> + + <para>On success, + <function>sd_event_source_set_priority()</function> and + <function>sd_event_source_get_priority()</function> return a + non-negative integer. On failure, they return a negative + errno-style error code.</para> + </refsect1> + + <refsect1> + <title>Errors</title> + + <para>Returned errors may indicate the following problems:</para> + + <variablelist> + <varlistentry> + <term><constant>-EINVAL</constant></term> + + <listitem><para><parameter>source</parameter> is not a valid + pointer to an <structname>sd_event_source</structname> + object.</para></listitem> + </varlistentry> + + <varlistentry> + <term><constant>-ENOMEM</constant></term> + + <listitem><para>Not enough memory.</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> + + </variablelist> + </refsect1> + + <xi:include href="libsystemd-pkgconfig.xml" /> + + <refsect1> + <title>See Also</title> + + <para> + <citerefentry><refentrytitle>sd-event</refentrytitle><manvolnum>3</manvolnum></citerefentry>, + <citerefentry><refentrytitle>sd_event_add_io</refentrytitle><manvolnum>3</manvolnum></citerefentry>, + <citerefentry><refentrytitle>sd_event_add_time</refentrytitle><manvolnum>3</manvolnum></citerefentry>, + <citerefentry><refentrytitle>sd_event_add_child</refentrytitle><manvolnum>3</manvolnum></citerefentry>, + <citerefentry><refentrytitle>sd_event_add_signal</refentrytitle><manvolnum>3</manvolnum></citerefentry>, + <citerefentry><refentrytitle>sd_event_add_defer</refentrytitle><manvolnum>3</manvolnum></citerefentry> + </para> + </refsect1> + +</refentry> diff --git a/man/sd_event_source_set_userdata.xml b/man/sd_event_source_set_userdata.xml new file mode 100644 index 0000000000..533d491b13 --- /dev/null +++ b/man/sd_event_source_set_userdata.xml @@ -0,0 +1,119 @@ +<?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_source_set_userdata" xmlns:xi="http://www.w3.org/2001/XInclude"> + + <refentryinfo> + <title>sd_event_source_set_userdata</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_source_set_userdata</refentrytitle> + <manvolnum>3</manvolnum> + </refmeta> + + <refnamediv> + <refname>sd_event_source_set_userdata</refname> + <refname>sd_event_source_get_userdata</refname> + + <refpurpose>Set or retrieve user data pointer of event sources</refpurpose> + </refnamediv> + + <refsynopsisdiv> + <funcsynopsis> + <funcsynopsisinfo>#include <systemd/sd-event.h></funcsynopsisinfo> + + <funcprototype> + <funcdef>void* <function>sd_event_source_set_userdata</function></funcdef> + <paramdef>sd_event_source *<parameter>source</parameter></paramdef> + <paramdef>void *<parameter>userdata</parameter></paramdef> + </funcprototype> + + <funcprototype> + <funcdef>void* <function>sd_event_source_get_userdata</function></funcdef> + <paramdef>sd_event_source *<parameter>source</parameter></paramdef> + </funcprototype> + + </funcsynopsis> + </refsynopsisdiv> + + <refsect1> + <title>Description</title> + + <para><function>sd_event_source_set_userdata()</function> may be + used to set an arbitrary user data pointer for the event source + object specified as <parameter>source</parameter>. The user data + pointer is usually specified when creating an event source object + with calls such as + <citerefentry><refentrytitle>sd_event_add_io</refentrytitle><manvolnum>3</manvolnum></citerefentry> + or + <citerefentry><refentrytitle>sd_event_add_time</refentrytitle><manvolnum>3</manvolnum></citerefentry>, + and may be updated with this call. The user data pointer is also + passed to all handler callback functions associated with the event + source. The <parameter>userdata</parameter> parameter specifies + the new user data pointer to set, the function returns the + previous user data pointer. Note that <constant>NULL</constant> is + a valid user data pointer.</para> + + <para><function>sd_event_source_get_userdata()</function> may be + used to query the current user data pointer assigned to the event + source object <parameter>source</parameter>.</para> + </refsect1> + + <refsect1> + <title>Return Value</title> + + <para>On success, + <function>sd_event_source_set_userdata()</function> and + <function>sd_event_source_get_userdata()</function> return the + previously set user data pointer. On failure, they return + NULL.</para> + </refsect1> + + <xi:include href="libsystemd-pkgconfig.xml" /> + + <refsect1> + <title>See Also</title> + + <para> + <citerefentry><refentrytitle>sd-event</refentrytitle><manvolnum>3</manvolnum></citerefentry>, + <citerefentry><refentrytitle>sd_event_add_io</refentrytitle><manvolnum>3</manvolnum></citerefentry>, + <citerefentry><refentrytitle>sd_event_add_time</refentrytitle><manvolnum>3</manvolnum></citerefentry>, + <citerefentry><refentrytitle>sd_event_add_child</refentrytitle><manvolnum>3</manvolnum></citerefentry>, + <citerefentry><refentrytitle>sd_event_add_signal</refentrytitle><manvolnum>3</manvolnum></citerefentry>, + <citerefentry><refentrytitle>sd_event_add_defer</refentrytitle><manvolnum>3</manvolnum></citerefentry>, + <citerefentry><refentrytitle>sd_event_source_set_description</refentrytitle><manvolnum>3</manvolnum></citerefentry> + </para> + </refsect1> + +</refentry> diff --git a/man/sd_event_source_unref.xml b/man/sd_event_source_unref.xml new file mode 100644 index 0000000000..579ec47e8e --- /dev/null +++ b/man/sd_event_source_unref.xml @@ -0,0 +1,125 @@ +<?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_source_unref" xmlns:xi="http://www.w3.org/2001/XInclude"> + + <refentryinfo> + <title>sd_event_source_unref</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_source_unref</refentrytitle> + <manvolnum>3</manvolnum> + </refmeta> + + <refnamediv> + <refname>sd_event_source_unref</refname> + <refname>sd_event_source_ref</refname> + + <refpurpose>Increase or decrease event source reference counters</refpurpose> + </refnamediv> + + <refsynopsisdiv> + <funcsynopsis> + <funcsynopsisinfo>#include <systemd/sd-event.h></funcsynopsisinfo> + + <funcprototype> + <funcdef>sd_event_source* <function>sd_event_source_unref</function></funcdef> + <paramdef>sd_event_source *<parameter>source</parameter></paramdef> + </funcprototype> + + <funcprototype> + <funcdef>sd_event_source* <function>sd_event_source_ref</function></funcdef> + <paramdef>sd_event_source *<parameter>source</parameter></paramdef> + </funcprototype> + + </funcsynopsis> + </refsynopsisdiv> + + <refsect1> + <title>Description</title> + + <para><function>sd_event_source_unref()</function> may be used to + decrement by one the reference counter of the event source object + specified as <parameter>source</parameter>. The reference counter + is initially set to one, when the event source is created with calls + such as + <citerefentry><refentrytitle>sd_event_add_io</refentrytitle><manvolnum>3</manvolnum></citerefentry> + or + <citerefentry><refentrytitle>sd_event_add_time</refentrytitle><manvolnum>3</manvolnum></citerefentry>. When + the reference counter reaches zero it is removed from its event loop + object and destroyed.</para> + + <para><function>sd_event_source_ref()</function> may be used + to increase by one the reference counter of the event source object + specified as <parameter>source</parameter>.</para> + + <para>Both functions execute no operation if the passed event + source object is <constant>NULL</constant>.</para> + + <para>Note that event source objects stay alive and may be + dispatched as long as they have a reference counter greater than + zero. In order to drop a reference of an event source and make + sure the associated event source handler function is not called + anymore it is recommended to combine a call of + <function>sd_event_source_unref()</function> with a prior call to + <function>sd_event_source_set_enabled()</function> with + <constant>SD_EVENT_OFF</constant>.</para> + </refsect1> + + <refsect1> + <title>Return Value</title> + + <para><function>sd_event_source_unref()</function> always returns + <constant>NULL</constant>. + <function>sd_event_source_ref()</function> always returns the + event source object passed in.</para> + </refsect1> + + <xi:include href="libsystemd-pkgconfig.xml" /> + + <refsect1> + <title>See Also</title> + + <para> + <citerefentry><refentrytitle>sd-event</refentrytitle><manvolnum>3</manvolnum></citerefentry>, + <citerefentry><refentrytitle>sd_event_add_io</refentrytitle><manvolnum>3</manvolnum></citerefentry>, + <citerefentry><refentrytitle>sd_event_add_time</refentrytitle><manvolnum>3</manvolnum></citerefentry>, + <citerefentry><refentrytitle>sd_event_add_child</refentrytitle><manvolnum>3</manvolnum></citerefentry>, + <citerefentry><refentrytitle>sd_event_add_signal</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> + </para> + </refsect1> + +</refentry> diff --git a/man/sd_event_wait.xml b/man/sd_event_wait.xml index 7ca50aedf9..1eefa80700 100644 --- a/man/sd_event_wait.xml +++ b/man/sd_event_wait.xml @@ -21,7 +21,7 @@ along with systemd; If not, see <http://www.gnu.org/licenses/>. --> -<refentry id="sd_event_wait"> +<refentry id="sd_event_wait" xmlns:xi="http://www.w3.org/2001/XInclude"> <refentryinfo> <title>sd_event_wait</title> @@ -46,14 +46,32 @@ <refname>sd_event_wait</refname> <refname>sd_event_prepare</refname> <refname>sd_event_dispatch</refname> - - <refpurpose>Run parts of the libsystemd event loop</refpurpose> + <refname>sd_event_get_state</refname> + <refname>SD_EVENT_INITIAL</refname> + <refname>SD_EVENT_PREPARING</refname> + <refname>SD_EVENT_ARMED</refname> + <refname>SD_EVENT_PENDING</refname> + <refname>SD_EVENT_RUNNING</refname> + <refname>SD_EVENT_EXITING</refname> + <refname>SD_EVENT_FINISHED</refname> + + <refpurpose>Low-level event loop operations</refpurpose> </refnamediv> <refsynopsisdiv> <funcsynopsis> <funcsynopsisinfo>#include <systemd/sd-event.h></funcsynopsisinfo> + <funcsynopsisinfo><token>enum</token> { + <constant>SD_EVENT_INITIAL</constant>, + <constant>SD_EVENT_PREPARING</constant>, + <constant>SD_EVENT_ARMED</constant>, + <constant>SD_EVENT_PENDING</constant>, + <constant>SD_EVENT_RUNNING</constant>, + <constant>SD_EVENT_EXITING</constant>, + <constant>SD_EVENT_FINISHED</constant>, +};</funcsynopsisinfo> + <funcprototype> <funcdef>int <function>sd_event_prepare</function></funcdef> <paramdef>sd_event *<parameter>event</parameter></paramdef> @@ -62,7 +80,7 @@ <funcprototype> <funcdef>int <function>sd_event_wait</function></funcdef> <paramdef>sd_event *<parameter>event</parameter></paramdef> - <paramdef>uint64_t <parameter>timeout</parameter></paramdef> + <paramdef>uint64_t <parameter>usec</parameter></paramdef> </funcprototype> <funcprototype> @@ -70,66 +88,184 @@ <paramdef>sd_event *<parameter>event</parameter></paramdef> </funcprototype> + <funcprototype> + <funcdef>int <function>sd_event_get_state</function></funcdef> + <paramdef>sd_event *<parameter>event</parameter></paramdef> + </funcprototype> + </funcsynopsis> </refsynopsisdiv> <refsect1> <title>Description</title> - <para>Functions described here form parts of an event loop.</para> - - <para><function>sd_event_prepare</function> checks for pending + <para>The low-level <function>sd_event_prepare()</function>, + <function>sd_event_wait()</function> and + <function>sd_event_dispatch()</function> functions may be used to + execute specific phases of an event loop. See + <citerefentry><refentrytitle>sd_event_run</refentrytitle><manvolnum>3</manvolnum></citerefentry> + and + <citerefentry><refentrytitle>sd_event_loop</refentrytitle><manvolnum>3</manvolnum></citerefentry> + for higher-level functions that execute individual but complete + iterations of an event loop or run it continously.</para> + + <para><function>sd_event_prepare()</function> checks for pending events and arms necessary timers. If any events are ready to be - processed, it returns a positive value, and the events should be - processed with <function>sd_event_dispatch</function>. - <function>sd_event_dispatch</function> runs a handler for one of - the events from the sources with the highest priority. On success, - <function>sd_event_dispatch</function> returns either 0, which - means that the loop is finished, or a positive value, which means - that the loop is again in the initial state and - <function>sd_event_prepare</function> should be called again. - </para> + processed ("pending"), it returns a positive, non-zero value, and the caller + should process these events with + <function>sd_event_dispatch()</function>.</para> + + <para><function>sd_event_dispatch()</function> dispatches the + highest priority event source that has a pending event. On + success, <function>sd_event_dispatch()</function> returns either + zero, which indicates that no further event sources may be + dispatched and exiting of the event loop was requested via + <citerefentry><refentrytitle>sd_event_exit</refentrytitle><manvolnum>3</manvolnum></citerefentry>; + or a positive non-zero value, which means that an event source was + dispatched and the loop returned to its initial state, and the + caller should initiate the next event loop iteration by invoking + <function>sd_event_prepare()</function> again.</para> + + <para>In case <function>sd_event_prepare()</function> returned + zero, <function>sd_event_wait()</function> should be called to + wait for further events or a timeout. If any events are ready to + be processed, it returns a positive, non-zero value, and the + events should be dispatched with + <function>sd_event_dispatch()</function>. Otherwise, the event + loop returned to its initial state and the next event loop + iteration should be initiated by invoking + <function>sd_event_prepare()</function> again.</para> + + <para><function>sd_event_get_state()</function> may be used to + determine the state the event loop is currently in. It returns one + of the states described below.</para> + + <para>All four functions take, as the first argument, the event + loop object <parameter>event</parameter> that has been created + with <function>sd_event_new()</function>. The timeout for + <function>sd_event_wait()</function> is specified in + <parameter>usec</parameter> in milliseconds. <constant>(uint64_t) + -1</constant> may be used to specify an infinite timeout.</para> +</refsect1> + + <refsect1> + <title>State Machine</title> + + <para>The event loop knows the following states, that may be + queried with <function>sd_event_get_state()</function>.</para> - <para>In case <function>sd_event_prepare</function> returned 0, - <function>sd_event_wait</function> should be called to wait for - events or a timeout. If any events are ready to be processed, it - returns a positive value, and the events should be processed with - <function>sd_event_dispatch</function>. Otherwise, the loop is - back in the initial state and <function>sd_event_prepare</function> - should be called again.</para> + <variablelist> + <varlistentry> + <term><constant>SD_EVENT_INITIAL</constant></term> + + <listitem><para>The initial state the event loop is in, + before each event loop iteration. Use + <function>sd_event_prepare()</function> to transition the + event loop into the <constant>SD_EVENT_ARMED</constant> or + <constant>SD_EVENT_PENDING</constant> states.</para></listitem> + </varlistentry> + + <varlistentry> + <term><constant>SD_EVENT_PREPARING</constant></term> + + <listitem><para>An event source is currently being prepared, + i.e. the preparation handler is currently being excuted, as + set with + <citerefentry><refentrytitle>sd_event_set_prepare</refentrytitle><manvolnum>3</manvolnum></citerefentry>. This + state is only seen in the event source preparation handler + that is invoked from the + <function>sd_event_prepare()</function> call and is + immediately followed by <constant>SD_EVENT_ARMED</constant> or + <constant>SD_EVENT_PENDING</constant>.</para></listitem> + </varlistentry> + + <varlistentry> + <term><constant>SD_EVENT_ARMED</constant></term> + + <listitem><para><function>sd_event_prepare()</function> has + been called and no event sources were ready to be + dispatched. Use <function>sd_event_wait()</function> to wait + for new events, and transition into + <constant>SD_EVENT_PENDING</constant> or back into + <constant>SD_EVENT_INITIAL</constant>.</para></listitem> + </varlistentry> + + <varlistentry> + <term><constant>SD_EVENT_PENDING</constant></term> + + <listitem><para><function>sd_event_prepare()</function> or + <function>sd_event_wait()</function> have been called and + there were event sources with events pending. Use + <function>sd_event_dispatch()</function> to dispatch the + highest priority event source and transition back to + <constant>SD_EVENT_INITIAL</constant>, or + <constant>SD_EVENT_FINISHED</constant>.</para></listitem> + </varlistentry> + + <varlistentry> + <term><constant>SD_EVENT_RUNNING</constant></term> + + <listitem><para>A regular event source is currently being + dispatched. This state is only seen in the event source + handler that is invoked from the + <function>sd_event_dispatch()</function> call, and is + immediately followed by <constant>SD_EVENT_INITIAL</constant> + or <constant>SD_EVENT_FINISHED</constant> as soon the event + source handler returns. Note that during dispatching of exit + event sources the <constant>SD_EVENT_EXITING</constant> state + is seen instead.</para></listitem> + </varlistentry> + + <varlistentry> + <term><constant>SD_EVENT_EXITING</constant></term> + + <listitem><para>Similar to + <constant>SD_EVENT_RUNNING</constant> but is the state in + effect while dispatching exit event sources. It is followed by + <constant>SD_EVENT_INITIAL</constant> or + <constant>SD_EVENT_FINISHED</constant> as soon as the event + handler returns.</para></listitem> + </varlistentry> + + <varlistentry> + <term><constant>SD_EVENT_FINISHED</constant></term> + + <listitem><para>The event loop has exited. All exit event + sources have run. If the event loop is in this state it serves + no purpose anymore, and should be freed.</para></listitem> + </varlistentry> + + </variablelist> + + <para>A simplified flow chart of the states and the calls to + transition between them is shown below. Note that + <constant>SD_EVENT_PREPARING</constant>, + <constant>SD_EVENT_RUNNING</constant> and + <constant>SD_EVENT_EXITING</constant> are not shown here.</para> <programlisting> - ┌──────────┐ - │ initial ├──←←←←←←←←←←←←←←←←←←←─┐ - └───┬──────┘ ↑ - │ ↑ - sd_event_prepare ┌─────────┐ ↑ - ├ 0 →→→→→→→──┤ armed │ ↑ - 1 └───┬─────┘ ↑ - ↓ │ ↑ - ↓ sd_event_wait ↑ - ├───←←←←←←←─── 1 ┴─ 0 →→→→→→→─┘ - ┌───┴──────┐ ↑ - │ pending │ ↑ - └───┬──────┘ ↑ - │ ↑ - sd_event_dispatch ↑ - ↓ ↑ - ├ 1 ──────────→→→→→→→─────────┘ - 0 - ↓ - ┌───┴──────┐ - │ finished │ - └──────────┘ + INITIAL -<---<---<---<---<---<---<---<---<---<---<---<---\ + | | + | ^ + | | + v ret == 0 | + sd_event_prepare() >--->--->--->--->- ARMED | + | | ^ + | ret > 0 | | + | | | + v v ret == 0 | + PENDING <---<---<---<---<---< sd_event_wait() >--->--->--+ + | ret > 0 ^ + | | + | | + v | + sd_event_dispatch() >--->--->--->--->--->--->--->--->--->--->/ + | ret > 0 + | ret == 0 + | + v + FINISHED </programlisting> - - <para>All three functions take, as the first argument, the event - loop object <parameter>event</parameter> that is created with - <function>sd_event_new</function>. The timeout for - <function>sd_event_wait</function> is specified with - <parameter>timeout</parameter> in milliseconds. - <constant>(uint64_t) -1</constant> may be used to specify an - infinite timeout.</para> </refsect1> <refsect1> @@ -137,13 +273,15 @@ <para>On success, these functions return 0 or a positive integer. On failure, they return a negative errno-style error code. In case - of <function>sd_event_prepare</function> and - <function>sd_event_wait</function>, a positive value means that - events are ready to be processed and 0 means that no events are - ready. In case of <function>sd_event_dispatch</function>, a - positive value means that the loop is again in the initial state - and 0 means the loop is finished. For any of these functions, a - negative return value means the loop must be aborted.</para> + of <function>sd_event_prepare()</function> and + <function>sd_event_wait()</function>, a positive, non-zero return + code indicates that events are ready to be processed and zero + indicates that no events are ready. In case of + <function>sd_event_dispatch()</function>, a positive, non-zero + return code indicates that the event loop returned to its initial + state and zero indicates the event loop has + exited. <function>sd_event_get_state()</function> returns a + positive or zero state on success.</para> </refsect1> <refsect1> @@ -156,7 +294,7 @@ <term><constant>-EINVAL</constant></term> <listitem><para>The <parameter>event</parameter> parameter is - <constant>NULL</constant>.</para></listitem> + invalid or <constant>NULL</constant>.</para></listitem> </varlistentry> <varlistentry> @@ -185,14 +323,7 @@ <para>Other errors are possible, too.</para> </refsect1> - <refsect1> - <title>Notes</title> - - <para>Functions described here are available - as a shared library, which can be compiled and linked to with the - <constant>libsystemd</constant> <citerefentry project='die-net'><refentrytitle>pkg-config</refentrytitle><manvolnum>1</manvolnum></citerefentry> - file.</para> - </refsect1> + <xi:include href="libsystemd-pkgconfig.xml" /> <refsect1> <title>See Also</title> @@ -200,13 +331,15 @@ <para> <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>, <citerefentry><refentrytitle>sd_event_new</refentrytitle><manvolnum>3</manvolnum></citerefentry>, - <citerefentry><refentrytitle>sd_event_run</refentrytitle><manvolnum>3</manvolnum></citerefentry>, <citerefentry><refentrytitle>sd_event_add_io</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_defer</refentrytitle><manvolnum>3</manvolnum></citerefentry>, <citerefentry><refentrytitle>sd_event_add_exit</refentrytitle><manvolnum>3</manvolnum></citerefentry>, - <citerefentry><refentrytitle>sd_event_add_post</refentrytitle><manvolnum>3</manvolnum></citerefentry>. + <citerefentry><refentrytitle>sd_event_add_post</refentrytitle><manvolnum>3</manvolnum></citerefentry>, + <citerefentry><refentrytitle>sd_event_run</refentrytitle><manvolnum>3</manvolnum></citerefentry>, + <citerefentry><refentrytitle>sd_event_get_fd</refentrytitle><manvolnum>3</manvolnum></citerefentry>, + <citerefentry><refentrytitle>sd_event_source_set_prepare</refentrytitle><manvolnum>3</manvolnum></citerefentry> </para> </refsect1> diff --git a/man/sd_watchdog_enabled.xml b/man/sd_watchdog_enabled.xml index 144ab1db61..6e27528a71 100644 --- a/man/sd_watchdog_enabled.xml +++ b/man/sd_watchdog_enabled.xml @@ -98,6 +98,11 @@ <varname>WatchdogSec=</varname> in service files. See <citerefentry><refentrytitle>systemd.service</refentrytitle><manvolnum>5</manvolnum></citerefentry> for details.</para> + + <para>Use + <citerefentry><refentrytitle>sd_event_set_watchdog</refentrytitle><manvolnum>3</manvolnum></citerefentry> + to enable automatic watchdog support in + <citerefentry><refentrytitle>sd-event</refentrytitle><manvolnum>3</manvolnum></citerefentry>-based event loops.</para> </refsect1> <refsect1> @@ -168,7 +173,8 @@ <citerefentry><refentrytitle>sd-daemon</refentrytitle><manvolnum>3</manvolnum></citerefentry>, <citerefentry><refentrytitle>daemon</refentrytitle><manvolnum>7</manvolnum></citerefentry>, <citerefentry><refentrytitle>systemd.service</refentrytitle><manvolnum>5</manvolnum></citerefentry>, - <citerefentry><refentrytitle>sd_notify</refentrytitle><manvolnum>3</manvolnum></citerefentry> + <citerefentry><refentrytitle>sd_notify</refentrytitle><manvolnum>3</manvolnum></citerefentry>, + <citerefentry><refentrytitle>sd_event_set_watchdog</refentrytitle><manvolnum>3</manvolnum></citerefentry> </para> </refsect1> diff --git a/man/systemd.service.xml b/man/systemd.service.xml index 20a71afe59..596bbcda36 100644 --- a/man/systemd.service.xml +++ b/man/systemd.service.xml @@ -678,8 +678,10 @@ <constant>SIGPIPE</constant>. Exit status definitions can either be numeric exit codes or termination signal names, separated by spaces. For example: - <programlisting>SuccessExitStatus=1 2 8 - SIGKILL</programlisting> ensures that exit codes 1, 2, 8 and + + <programlisting>SuccessExitStatus=1 2 8 SIGKILL</programlisting> + + ensures that exit codes 1, 2, 8 and the termination signal <constant>SIGKILL</constant> are considered clean service terminations. </para> @@ -711,14 +713,16 @@ signal names, and are separated by spaces. Defaults to the empty list, so that, by default, no exit status is excluded from the configured restart logic. For example: - <programlisting>RestartPreventExitStatus=1 6 - SIGABRT</programlisting> ensures that exit codes 1 and 6 and - the termination signal <constant>SIGABRT</constant> will not - result in automatic service restarting. This option may appear - more than once, in which case the list of restart-preventing - statuses is merged. If the empty string is assigned to this - option, the list is reset and all prior assignments of this - option will have no effect.</para></listitem> + + <programlisting>RestartPreventExitStatus=1 6 SIGABRT</programlisting> + + ensures that exit codes 1 and 6 and the termination signal + <constant>SIGABRT</constant> will not result in automatic + service restarting. This option may appear more than once, in + which case the list of restart-preventing statuses is + merged. If the empty string is assigned to this option, the + list is reset and all prior assignments of this option will + have no effect.</para></listitem> </varlistentry> <varlistentry> |