mirror of
https://github.com/systemd/systemd
synced 2024-09-06 16:56:43 +00:00
![Zbigniew Jędrzejewski-Szmek](/assets/img/avatar_default.png)
The only difference is that functions are not individually listed by name, but that seems completely pointless, since all functions that are documented are always exported, so the generic text tells the user all she or he needs to know.
112 lines
4.7 KiB
XML
112 lines
4.7 KiB
XML
<?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">
|
|
|
|
<!-- SPDX-License-Identifier: LGPL-2.1+ -->
|
|
|
|
<refentry id="sd_bus_slot_set_floating" xmlns:xi="http://www.w3.org/2001/XInclude">
|
|
|
|
<refentryinfo>
|
|
<title>sd_bus_slot_set_floating</title>
|
|
<productname>systemd</productname>
|
|
</refentryinfo>
|
|
|
|
<refmeta>
|
|
<refentrytitle>sd_bus_slot_set_floating</refentrytitle>
|
|
<manvolnum>3</manvolnum>
|
|
</refmeta>
|
|
|
|
<refnamediv>
|
|
<refname>sd_bus_slot_set_floating</refname>
|
|
<refname>sd_bus_slot_get_floating</refname>
|
|
|
|
<refpurpose>Control whether a bus slot object is "floating".</refpurpose>
|
|
</refnamediv>
|
|
|
|
<refsynopsisdiv>
|
|
<funcsynopsis>
|
|
<funcsynopsisinfo>#include <systemd/sd-bus.h></funcsynopsisinfo>
|
|
|
|
<funcprototype>
|
|
<funcdef>int <function>sd_bus_slot_set_floating</function></funcdef>
|
|
<paramdef>sd_bus_slot *<parameter>bus</parameter></paramdef>
|
|
<paramdef>int <parameter>b</parameter></paramdef>
|
|
</funcprototype>
|
|
|
|
<funcprototype>
|
|
<funcdef>int <function>sd_bus_slot_get_floating</function></funcdef>
|
|
<paramdef>sd_bus_slot *<parameter>slot</parameter></paramdef>
|
|
</funcprototype>
|
|
|
|
</funcsynopsis>
|
|
</refsynopsisdiv>
|
|
|
|
<refsect1>
|
|
<title>Description</title>
|
|
|
|
<para><function>sd_bus_slot_set_floating()</function> controls whether the specified bus slot object
|
|
<parameter>slot</parameter> shall be "floating" or not. A floating bus slot object's lifetime is bound to the
|
|
lifetime of the bus object it is associated with, meaning that it remains allocated as long as the bus object
|
|
itself and is freed automatically when the bus object is freed. Regular (i.e. non-floating) bus slot objects keep
|
|
the bus referenced, hence the bus object remains allocated at least as long as there remains at least one
|
|
referenced bus slot object around. The floating state hence controls the direction of referencing between the bus
|
|
object and the bus slot objects: if floating the bus pins the the bus slot, and otherwise the bus slot pins the bus
|
|
objects. Use <function>sd_bus_slot_set_floating()</function> to switch between both modes: if the
|
|
<parameter>b</parameter> parameter is zero, the slot object is considered floating, otherwise it is made a regular
|
|
(non-floating) slot object.</para>
|
|
|
|
<para>Bus slot objects may be allocated with calls such as
|
|
<citerefentry><refentrytitle>sd_bus_add_match</refentrytitle><manvolnum>3</manvolnum></citerefentry>. If the
|
|
<parameter>slot</parameter> of these functions is non-<constant>NULL</constant> the slot object will be of the
|
|
regular kind (i.e. non-floating), otherwise it will be created floating. With
|
|
<function>sd_bus_slot_set_floating()</function> a bus slot object allocated as regular can be converted into a
|
|
floating object and back. This is particularly useful for creating a bus slot object, then changing parameters of
|
|
it, and then turning it into a floating object, whose lifecycle is managed by the bus object.</para>
|
|
|
|
<para><function>sd_bus_slot_get_floating()</function> returns the current floating state of the specified bus slot
|
|
object. It returns negative on error, zero if the bus slot object is a regular (non-floating) object and positive
|
|
otherwise.</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>-ECHILD</constant></term>
|
|
|
|
<listitem><para>The bus connection has been created in a different process.</para></listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry>
|
|
<term><constant>-ESTALE</constant></term>
|
|
|
|
<listitem><para>The bus object the specified bus slot object is associated with has already been freed, and
|
|
hence no change in the floating state can be made anymore.</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-bus</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
|
|
<citerefentry><refentrytitle>sd_bus_add_match</refentrytitle><manvolnum>3</manvolnum></citerefentry>
|
|
</para>
|
|
</refsect1>
|
|
|
|
</refentry>
|