Adding upstream version 255.4.upstream/255.4

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 220 insertions, 0 deletions

diff --git a/man/sd_bus_call.xml b/man/sd_bus_call.xml
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+<?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_bus_call"
+          xmlns:xi="http://www.w3.org/2001/XInclude">
+
+  <refentryinfo>
+    <title>sd_bus_call</title>
+    <productname>systemd</productname>
+  </refentryinfo>
+
+  <refmeta>
+    <refentrytitle>sd_bus_call</refentrytitle>
+    <manvolnum>3</manvolnum>
+  </refmeta>
+
+  <refnamediv>
+    <refname>sd_bus_call</refname>
+    <refname>sd_bus_call_async</refname>
+
+    <refpurpose>Invoke a D-Bus method call</refpurpose>
+  </refnamediv>
+
+  <refsynopsisdiv>
+    <funcsynopsis>
+      <funcsynopsisinfo>#include &lt;systemd/sd-bus.h&gt;</funcsynopsisinfo>
+
+      <xi:include href="sd_bus_add_match.xml" xpointer="sd_bus_message_handler_t"/>
+
+      <funcprototype>
+        <funcdef>int <function>sd_bus_call</function></funcdef>
+        <paramdef>sd_bus *<parameter>bus</parameter></paramdef>
+        <paramdef>sd_bus_message *<parameter>m</parameter></paramdef>
+        <paramdef>uint64_t <parameter>usec</parameter></paramdef>
+        <paramdef>sd_bus_error *<parameter>ret_error</parameter></paramdef>
+        <paramdef>sd_bus_message **<parameter>reply</parameter></paramdef>
+      </funcprototype>
+
+      <funcprototype>
+        <funcdef>int <function>sd_bus_call_async</function></funcdef>
+        <paramdef>sd_bus *<parameter>bus</parameter></paramdef>
+        <paramdef>sd_bus_slot **<parameter>slot</parameter></paramdef>
+        <paramdef>sd_bus_message *<parameter>m</parameter></paramdef>
+        <paramdef>sd_bus_message_handler_t <parameter>callback</parameter></paramdef>
+        <paramdef>void *<parameter>userdata</parameter></paramdef>
+        <paramdef>uint64_t <parameter>usec</parameter></paramdef>
+      </funcprototype>
+    </funcsynopsis>
+  </refsynopsisdiv>
+
+  <refsect1>
+    <title>Description</title>
+
+    <para><function>sd_bus_call()</function> takes a complete bus message object and calls the
+    corresponding D-Bus method. On success, the response is stored in <parameter>reply</parameter>.
+    <parameter>usec</parameter> indicates the timeout in microseconds. If
+    <parameter>ret_error</parameter> is not <constant>NULL</constant> and
+    <function>sd_bus_call()</function> fails (either because of an internal error or because it
+    received a D-Bus error reply), <parameter>ret_error</parameter> is initialized to an instance of
+    <structname>sd_bus_error</structname> describing the error.</para>
+
+    <para><function>sd_bus_call_async()</function> is like <function>sd_bus_call()</function> but works
+    asynchronously. The <parameter>callback</parameter> indicates the function to call when the response
+    arrives. The <parameter>userdata</parameter> pointer will be passed to the callback function, and may be
+    chosen freely by the caller. If <parameter>slot</parameter> is not <constant>NULL</constant> and
+    <function>sd_bus_call_async()</function> succeeds, <parameter>slot</parameter> is set to a slot object
+    which can be used to cancel the method call at a later time using
+    <citerefentry><refentrytitle>sd_bus_slot_unref</refentrytitle><manvolnum>3</manvolnum></citerefentry>.
+    If <parameter>slot</parameter> is <constant>NULL</constant>, the lifetime of the method call is bound to
+    the lifetime of the bus object itself, and it cannot be cancelled independently. See
+    <citerefentry><refentrytitle>sd_bus_slot_set_floating</refentrytitle><manvolnum>3</manvolnum></citerefentry>
+    for details. <parameter>callback</parameter> is called when a reply arrives with the reply,
+    <parameter>userdata</parameter> and an <structname>sd_bus_error</structname> output parameter as its
+    arguments. Unlike <function>sd_bus_call()</function>, the <structname>sd_bus_error</structname> output
+    parameter passed to the callback will be empty. To determine whether the method call succeeded, use
+    <citerefentry><refentrytitle>sd_bus_message_is_method_error</refentrytitle><manvolnum>3</manvolnum></citerefentry>
+    on the reply message passed to the callback instead. If the callback returns zero and the
+    <structname>sd_bus_error</structname> output parameter is still empty when the callback finishes, other
+    handlers registered with functions such as
+    <citerefentry><refentrytitle>sd_bus_add_filter</refentrytitle><manvolnum>3</manvolnum></citerefentry> or
+    <citerefentry><refentrytitle>sd_bus_add_match</refentrytitle><manvolnum>3</manvolnum></citerefentry> are
+    given a chance to process the message. If the callback returns a non-zero value or the
+    <structname>sd_bus_error</structname> output parameter is not empty when the callback finishes, no
+    further processing of the message is done. Generally, you want to return zero from the callback to give
+    other registered handlers a chance to process the reply as well. (Note that the
+    <structname>sd_bus_error</structname> parameter is an output parameter of the callback function, not an
+    input parameter; it can be used to propagate errors from the callback handler, it will not receive any
+    error that was received as method reply.)</para>
+
+    <para>The message <parameter>m</parameter> passed to the callback is only borrowed, that is, the callback should
+    not call <citerefentry><refentrytitle>sd_bus_message_unref</refentrytitle><manvolnum>3</manvolnum></citerefentry>
+    on it. If the callback wants to hold on to the message beyond the lifetime of the callback, it needs to call
+    <citerefentry><refentrytitle>sd_bus_message_ref</refentrytitle><manvolnum>3</manvolnum></citerefentry> to create a
+    new reference.</para>
+
+    <para>If <parameter>usec</parameter> is zero, the default D-Bus method call timeout is used. See
+    <citerefentry><refentrytitle>sd_bus_get_method_call_timeout</refentrytitle><manvolnum>3</manvolnum></citerefentry>.
+    </para>
+
+  </refsect1>
+
+  <refsect1>
+    <title>Return Value</title>
+
+    <para>On success, these functions return a non-negative integer. On failure, they return a
+    negative errno-style error code.</para>
+
+    <refsect2 id='errors'>
+      <title>Errors</title>
+
+      <para>When <function>sd_bus_call()</function> internally receives a D-Bus error reply, it will set
+      <parameter>ret_error</parameter> if it is not <constant>NULL</constant>, and will return a negative
+      value mapped from the error reply, see
+      <citerefentry><refentrytitle>sd_bus_error_get_errno</refentrytitle><manvolnum>3</manvolnum></citerefentry>.
+      </para>
+
+      <para>Returned errors may indicate the following problems:</para>
+
+      <variablelist>
+        <varlistentry>
+          <term><constant>-EINVAL</constant></term>
+
+          <listitem><para>The input parameter <parameter>m</parameter> is <constant>NULL</constant>.
+          </para>
+
+          <xi:include href="version-info.xml" xpointer="v246"/></listitem>
+
+          <listitem><para>The input parameter <parameter>m</parameter> is not a D-Bus method call.
+          To create a new D-Bus method call, use
+          <citerefentry><refentrytitle>sd_bus_message_new_method_call</refentrytitle><manvolnum>3</manvolnum></citerefentry>.
+          </para></listitem>
+
+          <listitem><para>The input parameter <parameter>m</parameter> has the
+          <constant>BUS_MESSAGE_NO_REPLY_EXPECTED</constant> flag set.</para></listitem>
+
+          <listitem><para>The input parameter <parameter>error</parameter> is
+          non-<constant>NULL</constant> but was not set to <constant>SD_BUS_ERROR_NULL</constant>.
+          </para></listitem>
+        </varlistentry>
+
+        <varlistentry>
+          <term><constant>-ECHILD</constant></term>
+
+          <listitem><para>The bus connection was allocated in a parent process and is being reused
+          in a child process after <function>fork()</function>.</para>
+
+          <xi:include href="version-info.xml" xpointer="v246"/></listitem>
+        </varlistentry>
+
+        <varlistentry>
+          <term><constant>-ENOTCONN</constant></term>
+
+          <listitem><para>The input parameter <parameter>bus</parameter> is
+          <constant>NULL</constant> or the bus is not connected.</para>
+
+          <xi:include href="version-info.xml" xpointer="v246"/></listitem>
+        </varlistentry>
+
+        <varlistentry>
+          <term><constant>-ECONNRESET</constant></term>
+
+          <listitem><para>The bus connection was closed while waiting for the response.
+          </para>
+
+          <xi:include href="version-info.xml" xpointer="v246"/></listitem>
+        </varlistentry>
+
+        <varlistentry>
+          <term><constant>-ETIMEDOUT</constant></term>
+
+          <listitem><para>A response was not received within the given timeout.</para>
+
+          <xi:include href="version-info.xml" xpointer="v246"/></listitem>
+        </varlistentry>
+
+        <varlistentry>
+          <term><constant>-ELOOP</constant></term>
+
+          <listitem><para>The message <parameter>m</parameter> is addressed to its own client.
+          </para>
+
+          <xi:include href="version-info.xml" xpointer="v246"/></listitem>
+        </varlistentry>
+
+        <varlistentry>
+          <term><constant>-ENOMEM</constant></term>
+
+          <listitem><para>Memory allocation failed.</para>
+
+          <xi:include href="version-info.xml" xpointer="v246"/></listitem>
+        </varlistentry>
+      </variablelist>
+    </refsect2>
+  </refsect1>
+
+  <xi:include href="libsystemd-pkgconfig.xml" />
+
+  <refsect1>
+    <title>History</title>
+    <para><function>sd_bus_call()</function> and
+    <function>sd_bus_call_async()</function> were added in version 246.</para>
+  </refsect1>
+
+  <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_call_method</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
+      <citerefentry><refentrytitle>sd_bus_call_method_async</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
+      <citerefentry><refentrytitle>sd_bus_message_new_method_call</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
+      <citerefentry><refentrytitle>sd_bus_message_append</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
+      <citerefentry><refentrytitle>sd_bus_error</refentrytitle><manvolnum>3</manvolnum></citerefentry>
+    </para>
+  </refsect1>
+
+</refentry>