man: fully document sd-event interfaces

This completes the set of man pages for sd-event and contains some minor
other fixes for other man pages too.

The sd_event_set_name(3) man page is renamed to
sd_event_source_set_description(3), which is the correct name of the
concept today.

1 files changed, 179 insertions, 0 deletions

diff --git a/man/sd_event_source_set_enabled.xml b/man/sd_event_source_set_enabled.xml
new file mode 100644
index 0000000000..74c02e87bb
--- /dev/null
+++ b/man/sd_event_source_set_enabled.xml
@@ -0,0 +1,179 @@
+<?xml version='1.0'?> <!--*- Mode: nxml; nxml-child-indent: 2; indent-tabs-mode: nil -*-->
+<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN"
+"http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">
+
+<!--
+  This file is part of systemd.
+
+  Copyright 2015 Lennart Poettering
+
+  systemd is free software; you can redistribute it and/or modify it
+  under the terms of the GNU Lesser General Public License as published by
+  the Free Software Foundation; either version 2.1 of the License, or
+  (at your option) any later version.
+
+  systemd is distributed in the hope that it will be useful, but
+  WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+  Lesser General Public License for more details.
+
+  You should have received a copy of the GNU Lesser General Public License
+  along with systemd; If not, see <http://www.gnu.org/licenses/>.
+-->
+
+<refentry id="sd_event_source_set_enabled" xmlns:xi="http://www.w3.org/2001/XInclude">
+
+  <refentryinfo>
+    <title>sd_event_source_set_enabled</title>
+    <productname>systemd</productname>
+
+    <authorgroup>
+      <author>
+        <contrib>Developer</contrib>
+        <firstname>Lennart</firstname>
+        <surname>Poettering</surname>
+        <email>lennart@poettering.net</email>
+      </author>
+    </authorgroup>
+  </refentryinfo>
+
+  <refmeta>
+    <refentrytitle>sd_event_source_set_enabled</refentrytitle>
+    <manvolnum>3</manvolnum>
+  </refmeta>
+
+  <refnamediv>
+    <refname>sd_event_source_set_enabled</refname>
+    <refname>sd_event_source_get_enabled</refname>
+    <refname>SD_EVENT_ON</refname>
+    <refname>SD_EVENT_OFF</refname>
+    <refname>SD_EVENT_ONESHOT</refname>
+
+    <refpurpose>Enable or disable event sources</refpurpose>
+  </refnamediv>
+
+  <refsynopsisdiv>
+    <funcsynopsis>
+      <funcsynopsisinfo>#include &lt;systemd/sd-event.h&gt;</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>