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diff --git a/man/sd_event_source_set_floating.xml b/man/sd_event_source_set_floating.xml new file mode 100644 index 0000000..7f3ed86 --- /dev/null +++ b/man/sd_event_source_set_floating.xml @@ -0,0 +1,118 @@ +<?xml version='1.0'?> +<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN" + "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd"> +<!-- SPDX-License-Identifier: LGPL-2.1-or-later --> + +<refentry id="sd_event_source_set_floating" xmlns:xi="http://www.w3.org/2001/XInclude"> + + <refentryinfo> + <title>sd_event_source_set_floating</title> + <productname>systemd</productname> + </refentryinfo> + + <refmeta> + <refentrytitle>sd_event_source_set_floating</refentrytitle> + <manvolnum>3</manvolnum> + </refmeta> + + <refnamediv> + <refname>sd_event_source_set_floating</refname> + <refname>sd_event_source_get_floating</refname> + + <refpurpose>Set or retrieve 'floating' state of event sources</refpurpose> + </refnamediv> + + <refsynopsisdiv> + <funcsynopsis> + <funcsynopsisinfo>#include <systemd/sd-event.h></funcsynopsisinfo> + + <funcprototype> + <funcdef>int <function>sd_event_source_set_floating</function></funcdef> + <paramdef>sd_event_source *<parameter>source</parameter></paramdef> + <paramdef>int <parameter>floating</parameter></paramdef> + </funcprototype> + + <funcprototype> + <funcdef>int <function>sd_event_source_get_floating</function></funcdef> + <paramdef>sd_event_source *<parameter>source</parameter></paramdef> + </funcprototype> + + </funcsynopsis> + </refsynopsisdiv> + + <refsect1> + <title>Description</title> + + <para><function>sd_event_source_set_floating()</function> takes a boolean and sets the 'floating' state + of the specified event source object. This is used to change the direction of reference counts for the + object and the event loop it is associated with. In non-floating mode, the event source object holds a + reference to the event loop object, but not vice versa. The creator of the event source object must hold + a reference to it as long as the source should exist. In floating mode, the event loop holds a reference + to the source object, and will decrease the reference count when being freed. This means that a reference + to the event loop should be held to prevent both from being destroyed.</para> + + <para>Various calls that allocate event source objects (i.e. + <citerefentry><refentrytitle>sd_event_add_io</refentrytitle><manvolnum>3</manvolnum></citerefentry>, + <citerefentry><refentrytitle>sd_event_add_time</refentrytitle><manvolnum>3</manvolnum></citerefentry> and + similar) will automatically set an event source object to 'floating' mode if the caller passed + <constant>NULL</constant> in the parameter used to return a reference to the event source object. + Nevertheless, it may be necessary to gain temporary access to the source object, for example to adjust + event source properties after allocation (e.g. its priority or description string). In those cases the + object may be created in non-floating mode, and the returned reference used to adjust the properties, and + the object marked as floating afterwards, and the reference in the caller dropped.</para> + + <para><function>sd_event_source_get_floating()</function> may be used to query the current 'floating' + state of the event source object <parameter>source</parameter>. It returns zero if 'floating' mode is + off, positive if it is on.</para> + </refsect1> + + <refsect1> + <title>Return Value</title> + + <para>On success, <function>sd_event_source_set_floating()</function> and + <function>sd_event_source_get_floating()</function> return a non-negative integer. On failure, they + return a negative errno-style error code.</para> + + <refsect2> + <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>-ECHILD</constant></term> + + <listitem><para>The event loop has been created in a different process.</para></listitem> + + </varlistentry> + + </variablelist> + </refsect2> + </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_signal</refentrytitle><manvolnum>3</manvolnum></citerefentry>, + <citerefentry><refentrytitle>sd_event_add_child</refentrytitle><manvolnum>3</manvolnum></citerefentry>, + <citerefentry><refentrytitle>sd_event_add_inotify</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>, + <citerefentry><refentrytitle>sd_event_source_set_priority</refentrytitle><manvolnum>3</manvolnum></citerefentry> + </para> + </refsect1> + +</refentry> |