man: document sd_bus_add_{object,fallback}_vtable
The interface provided by those two functions is huge, so this text could probably be made two or three times as long if all details were described. But I think it's a good start.
This commit is contained in:
Zbigniew Jędrzejewski-Szmek
parent
bf135d288d
commit
afb9c0c958
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@ -115,6 +115,21 @@ manpages = [
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'sd_bus_match_signal',
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'sd_bus_match_signal_async'],
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''],
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['sd_bus_add_object_vtable',
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'3',
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['SD_BUS_METHOD',
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'SD_BUS_METHOD_WITH_NAMES',
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'SD_BUS_METHOD_WITH_NAMES_OFFSET',
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'SD_BUS_METHOD_WITH_OFFSET',
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'SD_BUS_PARAM',
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'SD_BUS_PROPERTY',
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'SD_BUS_SIGNAL',
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'SD_BUS_SIGNAL_WITH_NAMES',
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'SD_BUS_VTABLE_END',
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'SD_BUS_VTABLE_START',
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'SD_BUS_WRITABLE_PROPERTY',
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'sd_bus_add_fallback_vtable'],
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''],
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['sd_bus_attach_event', '3', ['sd_bus_detach_event', 'sd_bus_get_event'], ''],
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['sd_bus_close', '3', ['sd_bus_flush'], ''],
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['sd_bus_creds_get_pid',
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@ -41,6 +41,7 @@
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<para>See
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<literallayout><citerefentry><refentrytitle>sd_bus_add_match</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
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<citerefentry><refentrytitle>sd_bus_add_object_vtable</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
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<citerefentry><refentrytitle>sd_bus_attach_event</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
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<citerefentry><refentrytitle>sd_bus_creds_get_pid</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
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<citerefentry><refentrytitle>sd_bus_creds_new_from_pid</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
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@ -0,0 +1,473 @@
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<?xml version='1.0'?> <!--*-nxml-*-->
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<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN"
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"http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">
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<!-- SPDX-License-Identifier: LGPL-2.1+ -->
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<refentry id="sd_bus_add_object_vtable"
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xmlns:xi="http://www.w3.org/2001/XInclude">
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<refentryinfo>
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<title>sd_bus_add_object_vtable</title>
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<productname>systemd</productname>
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</refentryinfo>
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<refmeta>
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<refentrytitle>sd_bus_add_object_vtable</refentrytitle>
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<manvolnum>3</manvolnum>
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</refmeta>
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<refnamediv>
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<refname>sd_bus_add_object_vtable</refname>
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<refname>sd_bus_add_fallback_vtable</refname>
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<refname>SD_BUS_VTABLE_START</refname>
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<refname>SD_BUS_VTABLE_END</refname>
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<refname>SD_BUS_METHOD_WITH_NAMES_OFFSET</refname>
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<refname>SD_BUS_METHOD_WITH_NAMES</refname>
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<refname>SD_BUS_METHOD_WITH_OFFSET</refname>
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<refname>SD_BUS_METHOD</refname>
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<refname>SD_BUS_SIGNAL_WITH_NAMES</refname>
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<refname>SD_BUS_SIGNAL</refname>
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<refname>SD_BUS_WRITABLE_PROPERTY</refname>
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<refname>SD_BUS_PROPERTY</refname>
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<refname>SD_BUS_PARAM</refname>
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<refpurpose>Declare properties and methods for a D-Bus path</refpurpose>
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</refnamediv>
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<refsynopsisdiv>
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<funcsynopsis>
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<funcsynopsisinfo>#include <systemd/sd-bus-vtable.h></funcsynopsisinfo>
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<funcprototype>
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<funcdef>typedef int (*<function>sd_bus_message_handler_t</function>)</funcdef>
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<paramdef>sd_bus_message *<parameter>m</parameter></paramdef>
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<paramdef>void *<parameter>userdata</parameter></paramdef>
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<paramdef>sd_bus_error *<parameter>ret_error</parameter></paramdef>
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</funcprototype>
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<funcprototype>
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<funcdef>typedef int (*<function>sd_bus_property_get_t</function>)</funcdef>
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<paramdef>sd_bus *<parameter>bus</parameter></paramdef>
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<paramdef>const char *<parameter>path</parameter></paramdef>
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<paramdef>const char *<parameter>interface</parameter></paramdef>
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<paramdef>const char *<parameter>property</parameter></paramdef>
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<paramdef>sd_bus_message *<parameter>reply</parameter></paramdef>
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<paramdef>void *<parameter>userdata</parameter></paramdef>
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<paramdef>sd_bus_error *<parameter>ret_error</parameter></paramdef>
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</funcprototype>
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<funcprototype>
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<funcdef>typedef int (*<function>sd_bus_property_set_t</function>)</funcdef>
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<paramdef>sd_bus *<parameter>bus</parameter></paramdef>
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<paramdef>const char *<parameter>path</parameter></paramdef>
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<paramdef>const char *<parameter>interface</parameter></paramdef>
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<paramdef>const char *<parameter>property</parameter></paramdef>
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<paramdef>sd_bus_message *<parameter>value</parameter></paramdef>
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<paramdef>void *<parameter>userdata</parameter></paramdef>
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<paramdef>sd_bus_error *<parameter>ret_error</parameter></paramdef>
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</funcprototype>
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<funcprototype>
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<funcdef>typedef int (*<function>sd_bus_object_find_t</function>)</funcdef>
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<paramdef>const char *<parameter>path</parameter></paramdef>
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<paramdef>const char *<parameter>interface</parameter></paramdef>
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<paramdef>void *<parameter>userdata</parameter></paramdef>
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<paramdef>void **<parameter>ret_found</parameter></paramdef>
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<paramdef>sd_bus_error *<parameter>ret_error</parameter></paramdef>
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</funcprototype>
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<funcprototype>
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<funcdef>int <function>sd_bus_add_object_vtable</function></funcdef>
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<paramdef>sd_bus *<parameter>bus</parameter></paramdef>
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<paramdef>sd_bus_slot **<parameter>slot</parameter></paramdef>
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<paramdef>const char *<parameter>path</parameter></paramdef>
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<paramdef>const char *<parameter>interface</parameter></paramdef>
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<paramdef>const sd_bus_vtable *<parameter>vtable</parameter></paramdef>
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<paramdef>void *<parameter>userdata</parameter></paramdef>
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</funcprototype>
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<funcprototype>
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<funcdef>int <function>sd_bus_add_fallback_vtable</function></funcdef>
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<paramdef>sd_bus *<parameter>bus</parameter></paramdef>
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<paramdef>sd_bus_slot **<parameter>slot</parameter></paramdef>
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<paramdef>const char *<parameter>prefix</parameter></paramdef>
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<paramdef>const char *<parameter>interface</parameter></paramdef>
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<paramdef>const sd_bus_vtable *<parameter>vtable</parameter></paramdef>
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<paramdef>sd_bus_object_find_t <parameter>find</parameter></paramdef>
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<paramdef>void *<parameter>userdata</parameter></paramdef>
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</funcprototype>
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<para>
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<constant>SD_BUS_VTABLE_START(<replaceable>flags</replaceable>)</constant>
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</para>
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<para>
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<constant>SD_BUS_VTABLE_END</constant>
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</para>
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<para>
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<constant>SD_BUS_METHOD_WITH_NAMES_OFFSET(
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<replaceable>member</replaceable>,
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<replaceable>signature</replaceable>,
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<replaceable>in_names</replaceable>,
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<replaceable>result</replaceable>,
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<replaceable>out_names</replaceable>,
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<replaceable>handler</replaceable>,
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<replaceable>offset</replaceable>,
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<replaceable>flags</replaceable>)
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</constant>
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</para>
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<para>
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<constant>SD_BUS_METHOD_WITH_NAMES(
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<replaceable>member</replaceable>,
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<replaceable>signature</replaceable>,
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<replaceable>in_names</replaceable>,
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<replaceable>result</replaceable>,
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<replaceable>out_names</replaceable>,
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<replaceable>handler</replaceable>,
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<replaceable>flags</replaceable>)
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</constant>
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</para>
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<para>
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<constant>SD_BUS_METHOD_WITH_OFFSET(
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<replaceable>member</replaceable>,
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<replaceable>signature</replaceable>,
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<replaceable>result</replaceable>,
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<replaceable>handler</replaceable>,
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<replaceable>offset</replaceable>,
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<replaceable>flags</replaceable>)
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</constant>
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</para>
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<para>
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<constant>SD_BUS_METHOD(
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<replaceable>member</replaceable>,
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<replaceable>signature</replaceable>,
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<replaceable>result</replaceable>,
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<replaceable>handler</replaceable>,
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<replaceable>flags</replaceable>)
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</constant>
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</para>
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<para>
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<constant>SD_BUS_SIGNAL_WITH_NAMES(
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<replaceable>member</replaceable>,
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<replaceable>signature</replaceable>,
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<replaceable>names</replaceable>,
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<replaceable>flags</replaceable>)
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</constant>
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</para>
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<para>
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<constant>SD_BUS_SIGNAL(
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<replaceable>member</replaceable>,
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<replaceable>signature</replaceable>,
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<replaceable>flags</replaceable>)
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</constant>
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</para>
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<para>
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<constant>SD_BUS_WRITABLE_PROPERTY(
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<replaceable>member</replaceable>,
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<replaceable>signature</replaceable>,
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<replaceable>get</replaceable>,
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<replaceable>set</replaceable>,
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<replaceable>offset</replaceable>,
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<replaceable>flags</replaceable>)
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</constant>
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</para>
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<para>
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<constant>SD_BUS_PROPERTY(
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<replaceable>member</replaceable>,
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<replaceable>signature</replaceable>,
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<replaceable>get</replaceable>,
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<replaceable>offset</replaceable>,
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<replaceable>flags</replaceable>)
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</constant>
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</para>
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<para>
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<constant>SD_BUS_PARAM(<replaceable>name</replaceable>)</constant>
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</para>
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</funcsynopsis>
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</refsynopsisdiv>
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<refsect1>
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<title>Description</title>
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<para><function>sd_bus_add_object_vtable()</function> is used to declare attributes for the path object
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path <parameter>path</parameter> connected to the bus connection <parameter>bus</parameter> under the
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interface <parameter>interface</parameter>. The table <parameter>vtable</parameter> may contain property
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declarations using <constant>SD_BUS_PROPERTY()</constant> or
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<constant>SD_BUS_WRITABLE_PROPERTY()</constant>, method declarations using
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<constant>SD_BUS_METHOD()</constant>, <constant>SD_BUS_METHOD_WITH_NAMES()</constant>,
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<constant>SD_BUS_METHOD_WITH_OFFSET()</constant>, or
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<constant>SD_BUS_METHOD_WITH_NAMES_OFFSET()</constant>, and signal declarations using
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<constant>SD_BUS_SIGNAL_WITH_NAMES()</constant> or <constant>SD_BUS_SIGNAL()</constant>, see below. The
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<replaceable>userdata</replaceable> parameter contains a pointer that will be passed to various callback
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functions. It may be specified as <constant>NULL</constant> if no value is necessary.</para>
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<para><function>sd_bus_add_object_vtable()</function> is similar to
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<function>sd_bus_add_object_vtable()</function>, but is used to register "fallback" attributes. When
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looking for an attribute declaration, bus object paths registered with
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<function>sd_bus_add_object_vtable()</function> are checked first. If no match is found, the fallback
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vtables are checked for each prefix of the bus object path, i.e. with the last slash-separated components
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successively removed. This allows the vtable to be used for an arbitrary number of dynamically created
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objects.</para>
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<para>Parameter <replaceable>find</replaceable> is a function which is used to locate the target object
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based on the bus object path <replaceable>path</replaceable>. It must return <constant>1</constant> and
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set the <parameter>ret_found</parameter> output parameter if the object is found, return
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<constant>0</constant> if the object was not found, and return a negative errno-style error code or
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initialize the error structure <replaceable>ret_error</replaceable> on error. The pointer passed in
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<parameter>ret_found</parameter> will be used as the <parameter>userdata</parameter> parameter for the
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callback functions (offset by the <parameter>offset</parameter> offsets as specified in the vtable
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entries).</para>
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<para>For both functions, a match slot is created internally. If the output parameter
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<replaceable>slot</replaceable> is <constant>NULL</constant>, a "floating" slot object is created, see
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<citerefentry><refentrytitle>sd_bus_slot_set_floating</refentrytitle><manvolnum>3</manvolnum></citerefentry>.
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Otherwise, a pointer to the slot object is returned. In that case, the reference to the slot object
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should be dropped when the vtable is not needed anymore, see
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<citerefentry><refentrytitle>sd_bus_slot_unref</refentrytitle><manvolnum>3</manvolnum></citerefentry>.
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</para>
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<refsect2>
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<title>The <structname>sd_bus_vtable</structname> array</title>
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<para>The array consists of the structures of type <structname>sd_bus_vtable</structname>, but it
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should never be filled in manually, but through one of the following macros:</para>
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<variablelist>
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<varlistentry>
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<term><constant>SD_BUS_VTABLE_START()</constant></term>
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<term><constant>SD_BUS_VTABLE_END</constant></term>
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<listitem><para>Those must always be the first and last element.</para></listitem>
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</varlistentry>
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<varlistentry>
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<term><constant>SD_BUS_METHOD_WITH_NAMES_OFFSET()</constant></term>
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<term><constant>SD_BUS_METHOD_WITH_NAMES()</constant></term>
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<term><constant>SD_BUS_METHOD_WITH_OFFSET()</constant></term>
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<term><constant>SD_BUS_METHOD()</constant></term>
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<listitem><para>Declare a D-Bus method with the name <replaceable>member</replaceable>, parameter
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signature <replaceable>signature</replaceable>, result signature <replaceable>result</replaceable>.
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Parameters <replaceable>in_names</replaceable> and <replaceable>out_names</replaceable> specify the
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argument names of the input and output arguments in the function signature. The handler function
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<replaceable>handler</replaceable> must be of type <function>sd_bus_message_handler_t</function>.
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It will be called to handle the incoming messages that call this method. It receives a pointer that
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is the <replaceable>userdata</replaceable> parameter passed to the registration function offset by
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<replaceable>offset</replaceable> bytes. This may be used to pass pointers to different fields in
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the same data structure to different methods in the same
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vtable. <replaceable>in_names</replaceable> and <replaceable>out_names</replaceable> should be
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created using the <constant>SD_BUS_PARAM()</constant> macro, see below. Parameter
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<replaceable>flags</replaceable> is a combination of flags, see below.</para>
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<para><constant>SD_BUS_METHOD_WITH_NAMES()</constant>,
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<constant>SD_BUS_METHOD_WITH_OFFSET()</constant>, and <constant>SD_BUS_METHOD()</constant> are
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variants which specify zero offset (<replaceable>userdata</replaceable> parameter is passed with
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no change), leave the names unset (i.e. no parameter names), or both.</para>
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</listitem>
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</varlistentry>
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<varlistentry>
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<term><constant>SD_BUS_SIGNAL_WITH_NAMES()</constant></term>
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<term><constant>SD_BUS_SIGNAL()</constant></term>
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<listitem><para>Declare a D-Bus signal with the name <replaceable>member</replaceable>,
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parameter signature <replaceable>signature</replaceable>, and argument names
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<replaceable>names</replaceable>. <replaceable>names</replaceable> should be
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created using the <constant>SD_BUS_PARAM()</constant> macro, see below.
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Parameter <replaceable>flags</replaceable> is a combination of flags, see below.
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</para>
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<para>Equivalent to <constant>SD_BUS_SIGNAL_WITH_NAMES()</constant> with the
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<replaceable>names</replaceable> paramater unset (i.e. no parameter names).</para>
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</listitem>
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</varlistentry>
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<varlistentry>
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<term><constant>SD_BUS_WRITABLE_PROPERTY()</constant></term>
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<term><constant>SD_BUS_PROPERTY()</constant></term>
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<listitem><para>Declare a D-Bus property with the name <replaceable>member</replaceable> and value
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signature <replaceable>signature</replaceable>. Parameters <replaceable>get</replaceable> and
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<replaceable>set</replaceable> are the getter and setter methods. They are called with a pointer
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that is the <replaceable>userdata</replaceable> parameter passed to the registration function
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offset by <replaceable>offset</replaceable> bytes. This may be used pass pointers to different
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fields in the same data structure to different setters and getters in the same vtable. Parameter
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<replaceable>flags</replaceable> is a combination of flags, see below.</para>
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<para>The setter and getter methods may be omitted (specified as <constant>NULL</constant>), if the
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property has one of the basic types or <literal>as</literal> in case of read-only properties. In
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those cases, the <replaceable>userdata</replaceable> and <replaceable>offset</replaceable>
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parameters must together point to valid variable of the corresponding type. A default setter and
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getters will be provided, which simply copy the argument between this variable and the message.
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</para>
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<para><constant>SD_BUS_PROPERTY()</constant> is used to define a read-only property.</para>
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</listitem>
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</varlistentry>
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<varlistentry>
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<term><constant>SD_BUS_PARAM()</constant></term>
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<listitem><para>Parameter names should be wrapped in this macro, see the example below.</para>
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</listitem>
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</varlistentry>
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</variablelist>
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</refsect2>
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<refsect2>
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<title>Flags</title>
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<para>The <replaceable>flags</replaceable> parameter is used to specify a combination of
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<ulink url="https://dbus.freedesktop.org/doc/dbus-specification.html#introspection-format">D-Bus annotations</ulink>.
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</para>
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<variablelist>
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<varlistentry>
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<term><constant>SD_BUS_VTABLE_DEPRECATED</constant></term>
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<listitem><para>Mark this vtable entry as deprecated using the
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<constant>org.freedesktop.DBus.Deprecated</constant> annotation in introspection data. If
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specified for <constant>SD_BUS_VTABLE_START()</constant>, the annotation is applied to the
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enclosing interface.</para></listitem>
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</varlistentry>
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<varlistentry>
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<term><constant>SD_BUS_VTABLE_HIDDEN</constant></term>
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<listitem><para>Make this vtable entry hidden. It will not be shown in introspection data. If
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specified for <constant>SD_BUS_VTABLE_START()</constant>, all entries in the array are hidden.
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</para>
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</listitem>
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</varlistentry>
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<varlistentry>
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<term><constant>SD_BUS_VTABLE_UNPRIVILEGED</constant></term>
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<listitem><para>Mark this vtable entry as unprivileged. If not specified, the
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<constant>org.freedesktop.systemd1.Privileged</constant> annotation with value
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<literal>true</literal> will be shown in introspection data.</para>
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</listitem>
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</varlistentry>
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|
||||
<varlistentry>
|
||||
<term><constant>SD_BUS_VTABLE_METHOD_NO_REPLY</constant></term>
|
||||
|
||||
<listitem><para>Mark his vtable entry as a method that will not return a reply using the
|
||||
<constant>org.freedesktop.DBus.Method.NoReply</constant> annotation in introspection data.
|
||||
</para></listitem>
|
||||
</varlistentry>
|
||||
|
||||
<varlistentry>
|
||||
<term><constant>SD_BUS_VTABLE_CONST</constant></term>
|
||||
<term><constant>SD_BUS_VTABLE_EMITS_CHANGE</constant></term>
|
||||
<term><constant>SD_BUS_VTABLE_EMITS_INVALIDATION</constant></term>
|
||||
|
||||
<listitem><para>Those three flags correspond to different values of the
|
||||
<constant>org.freedesktop.DBus.Property.EmitsChangedSignal</constant> annotation, which specifies
|
||||
whether the <constant>org.freedesktop.DBus.Properties.PropertiesChanged</constant> signal is
|
||||
emitted whenever the property changes. <constant>SD_BUS_VTABLE_CONST</constant> corresponds to
|
||||
<constant>const</constant> and means that the property never changes during the lifetime of the
|
||||
object it belongs to, so no signal needs to be emitted.
|
||||
<constant>SD_BUS_VTABLE_EMITS_CHANGE</constant> corresponds to <constant>true</constant> and means
|
||||
that the signal is emitted. <constant>SD_BUS_VTABLE_EMITS_INVALIDATION</constant> corresponds to
|
||||
<constant>invalides</constant> and means that the signal is emitted, but the value is not included
|
||||
in the signal.</para>
|
||||
</listitem>
|
||||
</varlistentry>
|
||||
|
||||
<varlistentry>
|
||||
<term><constant>SD_BUS_VTABLE_PROPERTY_EXPLICIT</constant></term>
|
||||
|
||||
<listitem><para>Mark this vtable property entry as requiring explicit request to for the value to
|
||||
be shown (generally because the value is large or slow to calculate). This entry cannot be combined
|
||||
with <constant>SD_BUS_VTABLE_EMITS_CHANGE</constant>, and will not be shown in property listings by
|
||||
default (e.g. <command>busctl introspect</command>). This corresponds to the
|
||||
<constant>org.freedesktop.systemd1.Explicit</constant> annotation in introspection data.</para>
|
||||
</listitem>
|
||||
</varlistentry>
|
||||
</variablelist>
|
||||
</refsect2>
|
||||
</refsect1>
|
||||
|
||||
<refsect1>
|
||||
<title>Examples</title>
|
||||
|
||||
<example>
|
||||
<title>Create a simple listener on the bus</title>
|
||||
|
||||
<programlisting><xi:include href="vtable-example.c" parse="text" /></programlisting>
|
||||
|
||||
<para>This creates a simple client on the bus (the user bus, when run as normal user).
|
||||
We may use the D-Bus <constant>org.freedesktop.DBus.Introspectable.Introspect</constant>
|
||||
call to acquire the XML description of the interface:</para>
|
||||
|
||||
<programlisting><xi:include href="vtable-example.xml" parse="text" /></programlisting>
|
||||
</example>
|
||||
</refsect1>
|
||||
|
||||
<refsect1>
|
||||
<title>Return Value</title>
|
||||
|
||||
<para>On success, <function>sd_bus_add_object_vtable</function> and
|
||||
<function>sd_bus_add_fallback_vtable</function> calls return 0 or a positive 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>One of the required parameters is <constant>NULL</constant> or invalid. A reserved
|
||||
D-Bus interface was passed as the <replaceable>interface</replaceable> parameter.</para></listitem>
|
||||
</varlistentry>
|
||||
|
||||
<varlistentry>
|
||||
<term><constant>-ENOPKG</constant></term>
|
||||
|
||||
<listitem><para>The bus cannot be resolved.</para></listitem>
|
||||
</varlistentry>
|
||||
|
||||
<varlistentry>
|
||||
<term><constant>-ECHILD</constant></term>
|
||||
|
||||
<listitem><para>The bus was created in a different process.</para></listitem>
|
||||
</varlistentry>
|
||||
|
||||
<varlistentry>
|
||||
<term><constant>-ENOMEM</constant></term>
|
||||
|
||||
<listitem><para>Memory allocation failed.</para></listitem>
|
||||
</varlistentry>
|
||||
|
||||
<varlistentry>
|
||||
<term><constant>-EPROTOTYPE</constant></term>
|
||||
|
||||
<listitem><para><function>sd_bus_add_object_vtable</function> and
|
||||
<function>sd_bus_add_fallback_vtable</function> have been both called
|
||||
for the same bus object path, which is not allowed.</para></listitem>
|
||||
</varlistentry>
|
||||
|
||||
<varlistentry>
|
||||
<term><constant>-EEXIST</constant></term>
|
||||
|
||||
<listitem><para>This vtable has already been registered for this
|
||||
<replaceable>interface</replaceable> and <replaceable>path</replaceable>.
|
||||
</para></listitem>
|
||||
</varlistentry>
|
||||
</variablelist>
|
||||
</refsect2>
|
||||
</refsect1>
|
||||
|
||||
<xi:include href="libsystemd-pkgconfig.xml" />
|
||||
|
||||
<refsect1>
|
||||
<title>See Also</title>
|
||||
|
||||
<para>
|
||||
<citerefentry><refentrytitle>sd-bus</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
|
||||
<citerefentry><refentrytitle>busctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>
|
||||
</para>
|
||||
</refsect1>
|
||||
</refentry>
|
||||
|
|
@ -0,0 +1,70 @@
|
|||
#include <errno.h>
|
||||
#include <stdbool.h>
|
||||
#include <stddef.h>
|
||||
#include <stdlib.h>
|
||||
#include <stdio.h>
|
||||
#include <systemd/sd-bus.h>
|
||||
|
||||
#define _cleanup_(f) __attribute__((cleanup(f)))
|
||||
|
||||
typedef struct object {
|
||||
char *name;
|
||||
uint32_t number;
|
||||
} object;
|
||||
|
||||
static int method(sd_bus_message *m, void *userdata, sd_bus_error *error) {
|
||||
printf("Got called with userdata=%p\n", userdata);
|
||||
return 1;
|
||||
}
|
||||
|
||||
static const sd_bus_vtable vtable[] = {
|
||||
SD_BUS_VTABLE_START(0),
|
||||
SD_BUS_METHOD(
|
||||
"Method1", "s", "s", method, 0),
|
||||
SD_BUS_METHOD_WITH_NAMES_OFFSET(
|
||||
"Method2",
|
||||
"so", SD_BUS_PARAM(string) SD_BUS_PARAM(path),
|
||||
"s", SD_BUS_PARAM(returnstring),
|
||||
method, offsetof(object, number),
|
||||
SD_BUS_VTABLE_DEPRECATED),
|
||||
SD_BUS_WRITABLE_PROPERTY(
|
||||
"AutomaticStringProperty", "s", NULL, NULL,
|
||||
offsetof(object, name),
|
||||
SD_BUS_VTABLE_PROPERTY_EMITS_CHANGE),
|
||||
SD_BUS_WRITABLE_PROPERTY(
|
||||
"AutomaticIntegerProperty", "u", NULL, NULL,
|
||||
offsetof(object, number),
|
||||
SD_BUS_VTABLE_PROPERTY_EMITS_INVALIDATION),
|
||||
SD_BUS_VTABLE_END
|
||||
};
|
||||
|
||||
#define check(x) ({ \
|
||||
int r = x; \
|
||||
errno = r < 0 ? -r : 0; \
|
||||
printf(#x ": %m\n"); \
|
||||
if (r < 0) \
|
||||
return EXIT_FAILURE; \
|
||||
})
|
||||
|
||||
int main(int argc, char **argv) {
|
||||
_cleanup_(sd_bus_flush_close_unrefp) sd_bus *bus = NULL;
|
||||
|
||||
sd_bus_default(&bus);
|
||||
|
||||
object object = { .number = 666 };
|
||||
check((object.name = strdup("name")) != NULL);
|
||||
|
||||
check(sd_bus_add_object_vtable(bus, NULL, "/object",
|
||||
"org.freedesktop.systemd.VtableExample",
|
||||
vtable,
|
||||
&object));
|
||||
|
||||
while (true) {
|
||||
check(sd_bus_wait(bus, UINT64_MAX));
|
||||
check(sd_bus_process(bus, NULL));
|
||||
}
|
||||
|
||||
free(object.name);
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
|
@ -0,0 +1,54 @@
|
|||
<!DOCTYPE node PUBLIC "-//freedesktop//DTD D-BUS Object Introspection 1.0//EN"
|
||||
"http://www.freedesktop.org/standards/dbus/1.0/introspect.dtd">
|
||||
<node>
|
||||
<interface name="org.freedesktop.DBus.Peer">
|
||||
<method name="Ping"/>
|
||||
<method name="GetMachineId">
|
||||
<arg type="s" name="machine_uuid" direction="out"/>
|
||||
</method>
|
||||
</interface>
|
||||
<interface name="org.freedesktop.DBus.Introspectable">
|
||||
<method name="Introspect">
|
||||
<arg name="data" type="s" direction="out"/>
|
||||
</method>
|
||||
</interface>
|
||||
<interface name="org.freedesktop.DBus.Properties">
|
||||
<method name="Get">
|
||||
<arg name="interface" direction="in" type="s"/>
|
||||
<arg name="property" direction="in" type="s"/>
|
||||
<arg name="value" direction="out" type="v"/>
|
||||
</method>
|
||||
<method name="GetAll">
|
||||
<arg name="interface" direction="in" type="s"/>
|
||||
<arg name="properties" direction="out" type="a{sv}"/>
|
||||
</method>
|
||||
<method name="Set">
|
||||
<arg name="interface" direction="in" type="s"/>
|
||||
<arg name="property" direction="in" type="s"/>
|
||||
<arg name="value" direction="in" type="v"/>
|
||||
</method>
|
||||
<signal name="PropertiesChanged">
|
||||
<arg type="s" name="interface"/>
|
||||
<arg type="a{sv}" name="changed_properties"/>
|
||||
<arg type="as" name="invalidated_properties"/>
|
||||
</signal>
|
||||
</interface>
|
||||
<interface name="org.freedesktop.systemd.VtableExample">
|
||||
<method name="Method1">
|
||||
<arg type="s" direction="in"/>
|
||||
<arg type="s" direction="out"/>
|
||||
</method>
|
||||
<method name="Method2">
|
||||
<arg type="s" name="string" direction="in"/>
|
||||
<arg type="o" name="path" direction="in"/>
|
||||
<arg type="s" name="returnstring" direction="out"/>
|
||||
<annotation name="org.freedesktop.DBus.Deprecated" value="true"/>
|
||||
</method>
|
||||
<property name="AutomaticStringProperty" type="s" access="readwrite">
|
||||
</property>
|
||||
<property name="AutomaticIntegerProperty" type="u" access="readwrite">
|
||||
<annotation name="org.freedesktop.DBus.Property.EmitsChangedSignal" value="invalidates"/>
|
||||
</property>
|
||||
</interface>
|
||||
</node>
|
||||
|
||||
Loading…
Reference in New Issue