man/os-release.5 \
man/sd-bus-errors.3 \
man/sd-daemon.3 \
+ man/sd-event.3 \
man/sd-id128.3 \
man/sd-journal.3 \
man/sd_booted.3 \
man/sd_bus_request_name.3 \
man/sd_event_add_child.3 \
man/sd_event_add_defer.3 \
+ man/sd_event_add_io.3 \
man/sd_event_add_signal.3 \
man/sd_event_add_time.3 \
+ man/sd_event_exit.3 \
man/sd_event_get_fd.3 \
man/sd_event_new.3 \
+ man/sd_event_now.3 \
man/sd_event_run.3 \
- man/sd_event_set_name.3 \
+ man/sd_event_set_watchdog.3 \
+ man/sd_event_source_get_event.3 \
+ man/sd_event_source_get_pending.3 \
+ man/sd_event_source_set_description.3 \
+ man/sd_event_source_set_enabled.3 \
+ man/sd_event_source_set_prepare.3 \
+ man/sd_event_source_set_priority.3 \
+ man/sd_event_source_set_userdata.3 \
+ man/sd_event_source_unref.3 \
man/sd_event_wait.3 \
man/sd_id128_get_machine.3 \
man/sd_id128_randomize.3 \
man/SD_DEBUG.3 \
man/SD_EMERG.3 \
man/SD_ERR.3 \
+ man/SD_EVENT_ARMED.3 \
+ man/SD_EVENT_EXITING.3 \
+ man/SD_EVENT_FINISHED.3 \
+ man/SD_EVENT_INITIAL.3 \
+ man/SD_EVENT_OFF.3 \
+ man/SD_EVENT_ON.3 \
+ man/SD_EVENT_ONESHOT.3 \
+ man/SD_EVENT_PENDING.3 \
+ man/SD_EVENT_PREPARING.3 \
+ man/SD_EVENT_PRIORITY_IDLE.3 \
+ man/SD_EVENT_PRIORITY_IMPORTANT.3 \
+ man/SD_EVENT_PRIORITY_NORMAL.3 \
+ man/SD_EVENT_RUNNING.3 \
man/SD_ID128_CONST_STR.3 \
man/SD_ID128_FORMAT_STR.3 \
man/SD_ID128_FORMAT_VAL.3 \
man/sd_bus_ref.3 \
man/sd_bus_release_name.3 \
man/sd_bus_unref.3 \
+ man/sd_event.3 \
man/sd_event_add_exit.3 \
man/sd_event_add_post.3 \
+ man/sd_event_child_handler_t.3 \
man/sd_event_default.3 \
man/sd_event_dispatch.3 \
- man/sd_event_get_name.3 \
+ man/sd_event_get_exit_code.3 \
+ man/sd_event_get_state.3 \
+ man/sd_event_get_tid.3 \
+ man/sd_event_get_watchdog.3 \
+ man/sd_event_handler_t.3 \
+ man/sd_event_io_handler_t.3 \
man/sd_event_loop.3 \
man/sd_event_prepare.3 \
man/sd_event_ref.3 \
+ man/sd_event_signal_handler_t.3 \
+ man/sd_event_source.3 \
man/sd_event_source_get_child_pid.3 \
+ man/sd_event_source_get_description.3 \
+ man/sd_event_source_get_enabled.3 \
+ man/sd_event_source_get_io_events.3 \
+ man/sd_event_source_get_io_fd.3 \
+ man/sd_event_source_get_io_revents.3 \
+ man/sd_event_source_get_priority.3 \
man/sd_event_source_get_signal.3 \
man/sd_event_source_get_time.3 \
man/sd_event_source_get_time_accuracy.3 \
man/sd_event_source_get_time_clock.3 \
+ man/sd_event_source_get_userdata.3 \
+ man/sd_event_source_ref.3 \
+ man/sd_event_source_set_io_events.3 \
+ man/sd_event_source_set_io_fd.3 \
man/sd_event_source_set_time.3 \
man/sd_event_source_set_time_accuracy.3 \
+ man/sd_event_time_handler_t.3 \
man/sd_event_unref.3 \
man/sd_id128_equal.3 \
man/sd_id128_from_string.3 \
man/SD_DEBUG.3: man/sd-daemon.3
man/SD_EMERG.3: man/sd-daemon.3
man/SD_ERR.3: man/sd-daemon.3
+man/SD_EVENT_ARMED.3: man/sd_event_wait.3
+man/SD_EVENT_EXITING.3: man/sd_event_wait.3
+man/SD_EVENT_FINISHED.3: man/sd_event_wait.3
+man/SD_EVENT_INITIAL.3: man/sd_event_wait.3
+man/SD_EVENT_OFF.3: man/sd_event_source_set_enabled.3
+man/SD_EVENT_ON.3: man/sd_event_source_set_enabled.3
+man/SD_EVENT_ONESHOT.3: man/sd_event_source_set_enabled.3
+man/SD_EVENT_PENDING.3: man/sd_event_wait.3
+man/SD_EVENT_PREPARING.3: man/sd_event_wait.3
+man/SD_EVENT_PRIORITY_IDLE.3: man/sd_event_source_set_priority.3
+man/SD_EVENT_PRIORITY_IMPORTANT.3: man/sd_event_source_set_priority.3
+man/SD_EVENT_PRIORITY_NORMAL.3: man/sd_event_source_set_priority.3
+man/SD_EVENT_RUNNING.3: man/sd_event_wait.3
man/SD_ID128_CONST_STR.3: man/sd-id128.3
man/SD_ID128_FORMAT_STR.3: man/sd-id128.3
man/SD_ID128_FORMAT_VAL.3: man/sd-id128.3
man/sd_bus_ref.3: man/sd_bus_new.3
man/sd_bus_release_name.3: man/sd_bus_request_name.3
man/sd_bus_unref.3: man/sd_bus_new.3
+man/sd_event.3: man/sd_event_new.3
man/sd_event_add_exit.3: man/sd_event_add_defer.3
man/sd_event_add_post.3: man/sd_event_add_defer.3
+man/sd_event_child_handler_t.3: man/sd_event_add_child.3
man/sd_event_default.3: man/sd_event_new.3
man/sd_event_dispatch.3: man/sd_event_wait.3
-man/sd_event_get_name.3: man/sd_event_set_name.3
+man/sd_event_get_exit_code.3: man/sd_event_exit.3
+man/sd_event_get_state.3: man/sd_event_wait.3
+man/sd_event_get_tid.3: man/sd_event_new.3
+man/sd_event_get_watchdog.3: man/sd_event_set_watchdog.3
+man/sd_event_handler_t.3: man/sd_event_add_defer.3
+man/sd_event_io_handler_t.3: man/sd_event_add_io.3
man/sd_event_loop.3: man/sd_event_run.3
man/sd_event_prepare.3: man/sd_event_wait.3
man/sd_event_ref.3: man/sd_event_new.3
+man/sd_event_signal_handler_t.3: man/sd_event_add_signal.3
+man/sd_event_source.3: man/sd_event_add_io.3
man/sd_event_source_get_child_pid.3: man/sd_event_add_child.3
+man/sd_event_source_get_description.3: man/sd_event_source_set_description.3
+man/sd_event_source_get_enabled.3: man/sd_event_source_set_enabled.3
+man/sd_event_source_get_io_events.3: man/sd_event_add_io.3
+man/sd_event_source_get_io_fd.3: man/sd_event_add_io.3
+man/sd_event_source_get_io_revents.3: man/sd_event_add_io.3
+man/sd_event_source_get_priority.3: man/sd_event_source_set_priority.3
man/sd_event_source_get_signal.3: man/sd_event_add_signal.3
man/sd_event_source_get_time.3: man/sd_event_add_time.3
man/sd_event_source_get_time_accuracy.3: man/sd_event_add_time.3
man/sd_event_source_get_time_clock.3: man/sd_event_add_time.3
+man/sd_event_source_get_userdata.3: man/sd_event_source_set_userdata.3
+man/sd_event_source_ref.3: man/sd_event_source_unref.3
+man/sd_event_source_set_io_events.3: man/sd_event_add_io.3
+man/sd_event_source_set_io_fd.3: man/sd_event_add_io.3
man/sd_event_source_set_time.3: man/sd_event_add_time.3
man/sd_event_source_set_time_accuracy.3: man/sd_event_add_time.3
+man/sd_event_time_handler_t.3: man/sd_event_add_time.3
man/sd_event_unref.3: man/sd_event_new.3
man/sd_id128_equal.3: man/sd-id128.3
man/sd_id128_from_string.3: man/sd_id128_to_string.3
man/SD_ERR.html: man/sd-daemon.html
$(html-alias)
+man/SD_EVENT_ARMED.html: man/sd_event_wait.html
+ $(html-alias)
+
+man/SD_EVENT_EXITING.html: man/sd_event_wait.html
+ $(html-alias)
+
+man/SD_EVENT_FINISHED.html: man/sd_event_wait.html
+ $(html-alias)
+
+man/SD_EVENT_INITIAL.html: man/sd_event_wait.html
+ $(html-alias)
+
+man/SD_EVENT_OFF.html: man/sd_event_source_set_enabled.html
+ $(html-alias)
+
+man/SD_EVENT_ON.html: man/sd_event_source_set_enabled.html
+ $(html-alias)
+
+man/SD_EVENT_ONESHOT.html: man/sd_event_source_set_enabled.html
+ $(html-alias)
+
+man/SD_EVENT_PENDING.html: man/sd_event_wait.html
+ $(html-alias)
+
+man/SD_EVENT_PREPARING.html: man/sd_event_wait.html
+ $(html-alias)
+
+man/SD_EVENT_PRIORITY_IDLE.html: man/sd_event_source_set_priority.html
+ $(html-alias)
+
+man/SD_EVENT_PRIORITY_IMPORTANT.html: man/sd_event_source_set_priority.html
+ $(html-alias)
+
+man/SD_EVENT_PRIORITY_NORMAL.html: man/sd_event_source_set_priority.html
+ $(html-alias)
+
+man/SD_EVENT_RUNNING.html: man/sd_event_wait.html
+ $(html-alias)
+
man/SD_ID128_CONST_STR.html: man/sd-id128.html
$(html-alias)
man/sd_bus_unref.html: man/sd_bus_new.html
$(html-alias)
+man/sd_event.html: man/sd_event_new.html
+ $(html-alias)
+
man/sd_event_add_exit.html: man/sd_event_add_defer.html
$(html-alias)
man/sd_event_add_post.html: man/sd_event_add_defer.html
$(html-alias)
+man/sd_event_child_handler_t.html: man/sd_event_add_child.html
+ $(html-alias)
+
man/sd_event_default.html: man/sd_event_new.html
$(html-alias)
man/sd_event_dispatch.html: man/sd_event_wait.html
$(html-alias)
-man/sd_event_get_name.html: man/sd_event_set_name.html
+man/sd_event_get_exit_code.html: man/sd_event_exit.html
+ $(html-alias)
+
+man/sd_event_get_state.html: man/sd_event_wait.html
+ $(html-alias)
+
+man/sd_event_get_tid.html: man/sd_event_new.html
+ $(html-alias)
+
+man/sd_event_get_watchdog.html: man/sd_event_set_watchdog.html
+ $(html-alias)
+
+man/sd_event_handler_t.html: man/sd_event_add_defer.html
+ $(html-alias)
+
+man/sd_event_io_handler_t.html: man/sd_event_add_io.html
$(html-alias)
man/sd_event_loop.html: man/sd_event_run.html
man/sd_event_ref.html: man/sd_event_new.html
$(html-alias)
+man/sd_event_signal_handler_t.html: man/sd_event_add_signal.html
+ $(html-alias)
+
+man/sd_event_source.html: man/sd_event_add_io.html
+ $(html-alias)
+
man/sd_event_source_get_child_pid.html: man/sd_event_add_child.html
$(html-alias)
+man/sd_event_source_get_description.html: man/sd_event_source_set_description.html
+ $(html-alias)
+
+man/sd_event_source_get_enabled.html: man/sd_event_source_set_enabled.html
+ $(html-alias)
+
+man/sd_event_source_get_io_events.html: man/sd_event_add_io.html
+ $(html-alias)
+
+man/sd_event_source_get_io_fd.html: man/sd_event_add_io.html
+ $(html-alias)
+
+man/sd_event_source_get_io_revents.html: man/sd_event_add_io.html
+ $(html-alias)
+
+man/sd_event_source_get_priority.html: man/sd_event_source_set_priority.html
+ $(html-alias)
+
man/sd_event_source_get_signal.html: man/sd_event_add_signal.html
$(html-alias)
man/sd_event_source_get_time_clock.html: man/sd_event_add_time.html
$(html-alias)
+man/sd_event_source_get_userdata.html: man/sd_event_source_set_userdata.html
+ $(html-alias)
+
+man/sd_event_source_ref.html: man/sd_event_source_unref.html
+ $(html-alias)
+
+man/sd_event_source_set_io_events.html: man/sd_event_add_io.html
+ $(html-alias)
+
+man/sd_event_source_set_io_fd.html: man/sd_event_add_io.html
+ $(html-alias)
+
man/sd_event_source_set_time.html: man/sd_event_add_time.html
$(html-alias)
man/sd_event_source_set_time_accuracy.html: man/sd_event_add_time.html
$(html-alias)
+man/sd_event_time_handler_t.html: man/sd_event_add_time.html
+ $(html-alias)
+
man/sd_event_unref.html: man/sd_event_new.html
$(html-alias)
man/runlevel.xml \
man/sd-bus-errors.xml \
man/sd-daemon.xml \
+ man/sd-event.xml \
man/sd-id128.xml \
man/sd-journal.xml \
man/sd-login.xml \
man/sd_bus_request_name.xml \
man/sd_event_add_child.xml \
man/sd_event_add_defer.xml \
+ man/sd_event_add_io.xml \
man/sd_event_add_signal.xml \
man/sd_event_add_time.xml \
+ man/sd_event_exit.xml \
man/sd_event_get_fd.xml \
man/sd_event_new.xml \
+ man/sd_event_now.xml \
man/sd_event_run.xml \
- man/sd_event_set_name.xml \
+ man/sd_event_set_watchdog.xml \
+ man/sd_event_source_get_event.xml \
+ man/sd_event_source_get_pending.xml \
+ man/sd_event_source_set_description.xml \
+ man/sd_event_source_set_enabled.xml \
+ man/sd_event_source_set_prepare.xml \
+ man/sd_event_source_set_priority.xml \
+ man/sd_event_source_set_userdata.xml \
+ man/sd_event_source_unref.xml \
man/sd_event_wait.xml \
man/sd_get_seats.xml \
man/sd_id128_get_machine.xml \
<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>,
--- /dev/null
+<?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>
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>
<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>
<paramdef>void *<parameter>userdata</parameter></paramdef>
</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>
<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>
<term><constant>-EBUSY</constant></term>
<listitem><para>A handler is already installed for this
- child.</para></listitem>
+ child process.</para></listitem>
</varlistentry>
</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>
<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>
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>
<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>
<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>
</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>
<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>
--- /dev/null
+<?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>
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>
<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>
<paramdef>void *<parameter>userdata</parameter></paramdef>
</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>
<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>
</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>
<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>
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>
<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>
<paramdef>void *<parameter>userdata</parameter></paramdef>
</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>u
sec_t *<parameter>usec</parameter></paramdef>
+ <paramdef>u
int64_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>u
sec_t <parameter>usec</parameter></paramdef>
+ <paramdef>u
int64_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>u
sec_t *<parameter>usec</parameter></paramdef>
+ <paramdef>u
int64_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>u
sec_t <parameter>usec</parameter></paramdef>
+ <paramdef>u
int64_t <parameter>usec</parameter></paramdef>
</funcprototype>
<funcprototype>
<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>
<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>
<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>
--- /dev/null
+<?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>
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>
<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>
<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>
<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>
<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>
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>
<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>
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>
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>
<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>
<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>
--- /dev/null
+<?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>
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>
<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>
<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>
<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>
<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>
<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>
<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>
+++ /dev/null
-<?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>
--- /dev/null
+<?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>
--- /dev/null
+<?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>
--- /dev/null
+<?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>
--- /dev/null
+<?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>
--- /dev/null
+<?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>
--- /dev/null
+<?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>
--- /dev/null
+<?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>
--- /dev/null
+<?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>
--- /dev/null
+<?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>
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>
<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>
<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>
<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>
<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>
<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>
<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>
<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>
<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>
<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>
<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>
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>
projects / thirdparty / systemd.git / commitdiff
