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Diffstat (limited to 'man/sd_bus_slot_set_destroy_callback.xml')
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diff --git a/man/sd_bus_slot_set_destroy_callback.xml b/man/sd_bus_slot_set_destroy_callback.xml new file mode 100644 index 0000000..80bfd86 --- /dev/null +++ b/man/sd_bus_slot_set_destroy_callback.xml @@ -0,0 +1,131 @@ +<?xml version='1.0'?> +<!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_destroy_callback" + xmlns:xi="http://www.w3.org/2001/XInclude"> + + <refentryinfo> + <title>sd_bus_slot_set_destroy_callback</title> + <productname>systemd</productname> + </refentryinfo> + + <refmeta> + <refentrytitle>sd_bus_slot_set_destroy_callback</refentrytitle> + <manvolnum>3</manvolnum> + </refmeta> + + <refnamediv> + <refname>sd_bus_slot_set_destroy_callback</refname> + <refname>sd_bus_slot_get_destroy_callback</refname> + <refname>sd_bus_track_set_destroy_callback</refname> + <refname>sd_bus_track_get_destroy_callback</refname> + <refname>sd_bus_destroy_t</refname> + + <refpurpose>Define the callback function for resource cleanup.</refpurpose> + </refnamediv> + + <refsynopsisdiv> + <funcsynopsis> + <funcsynopsisinfo>#include <systemd/sd-bus.h></funcsynopsisinfo> + + <funcprototype> + <funcdef>typedef int (*<function>sd_bus_destroy_t</function>)</funcdef> + <paramdef>void *<parameter>userdata</parameter></paramdef> + </funcprototype> + + <funcprototype> + <funcdef>int <function>sd_bus_slot_set_destroy_callback</function></funcdef> + <paramdef>sd_bus_slot *<parameter>slot</parameter></paramdef> + <paramdef>sd_bus_destroy_t <parameter>callback</parameter></paramdef> + </funcprototype> + + <funcprototype> + <funcdef>int <function>sd_bus_slot_get_destroy_callback</function></funcdef> + <paramdef>sd_bus_slot *<parameter>slot</parameter></paramdef> + <paramdef>sd_bus_destroy_t *<parameter>callback</parameter></paramdef> + </funcprototype> + + <funcprototype> + <funcdef>int <function>sd_bus_track_set_destroy_callback</function></funcdef> + <paramdef>sd_bus_track *<parameter>track</parameter></paramdef> + <paramdef>sd_bus_destroy_t <parameter>callback</parameter></paramdef> + </funcprototype> + + <funcprototype> + <funcdef>int <function>sd_bus_track_get_destroy_callback</function></funcdef> + <paramdef>sd_bus_track *<parameter>track</parameter></paramdef> + <paramdef>sd_bus_destroy_t *<parameter>callback</parameter></paramdef> + </funcprototype> + </funcsynopsis> + </refsynopsisdiv> + + <refsect1> + <title>Description</title> + + <para><function>sd_bus_slot_set_destroy_callback()</function> sets <parameter>callback</parameter> as the callback + function to be called right before the bus slot object <parameter>slot</parameter> is deallocated. The + <parameter>userdata</parameter> pointer from the slot object will be passed as the <parameter>userdata</parameter> + parameter. This pointer can be set by an argument to the constructor functions, see + <citerefentry><refentrytitle>sd_bus_add_match</refentrytitle><manvolnum>3</manvolnum></citerefentry>, or directly, + see <citerefentry><refentrytitle>sd_bus_slot_set_userdata</refentrytitle><manvolnum>3</manvolnum></citerefentry>. + This callback function is called even if <parameter>userdata</parameter> is <constant>NULL</constant>. Note that + this callback is invoked at a time where the bus slot object itself is already invalidated, and executing + operations or taking new references to the bus slot object is not permissible.</para> + + <para><function>sd_bus_slot_get_destroy_callback()</function> returns the current callback + for <parameter>slot</parameter> in the <parameter>callback</parameter> parameter.</para> + + <para><function>sd_bus_track_set_destroy_callback()</function> and + <function>sd_bus_track_get_destroy_callback()</function> provide equivalent functionality for the + <parameter>userdata</parameter> pointer associated with bus peer tracking objects. For details about bus peer + tracking objects, see + <citerefentry><refentrytitle>sd_bus_track_new</refentrytitle><manvolnum>3</manvolnum></citerefentry>.</para> + </refsect1> + + <refsect1> + <title>Return Value</title> + + <para>On success, <function>sd_bus_slot_set_destroy_callback()</function> and + <function>sd_bus_track_set_destroy_callback()</function> return 0 or a positive integer. On failure, they return a + negative errno-style error code.</para> + + <para><function>sd_bus_slot_get_destroy_callback()</function> and + <function>sd_bus_track_get_destroy_callback()</function> return positive if the destroy callback function is set, 0 + if not. 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 <parameter>slot</parameter> or <parameter>track</parameter> parameter is + <constant>NULL</constant>.</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_slot_set_floating</refentrytitle><manvolnum>3</manvolnum></citerefentry>, + <citerefentry><refentrytitle>sd_bus_add_match</refentrytitle><manvolnum>3</manvolnum></citerefentry>, + <citerefentry><refentrytitle>sd_bus_track_new</refentrytitle><manvolnum>3</manvolnum></citerefentry>, + <citerefentry><refentrytitle>sd_bus_slot_set_userdata</refentrytitle><manvolnum>3</manvolnum></citerefentry>, + <citerefentry><refentrytitle>sd_bus_track_set_userdata</refentrytitle><manvolnum>3</manvolnum></citerefentry> + </para> + </refsect1> + +</refentry> |