license: LGPL-2.1+ -> LGPL-2.1-or-later

[thirdparty/systemd.git] / man / sd_bus_new.xml

diff --git a/man/sd_bus_new.xml b/man/sd_bus_new.xml
index b095518f8fed0069ee5d1be4dd7c0bbf5c982515..355b34bad8e14be987d895cbcdd2d6bbf7ba97d2 100644 (file)
--- a/man/sd_bus_new.xml
+++ b/man/sd_bus_new.xml
@@ -1,10 +1,7 @@
 <?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+
--->
+<!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_new" xmlns:xi="http://www.w3.org/2001/XInclude">
 
@@ -23,6 +20,10 @@
     <refname>sd_bus_ref</refname>
     <refname>sd_bus_unref</refname>
     <refname>sd_bus_unrefp</refname>
+    <refname>sd_bus_close_unref</refname>
+    <refname>sd_bus_close_unrefp</refname>
+    <refname>sd_bus_flush_close_unref</refname>
+    <refname>sd_bus_flush_close_unrefp</refname>
 
     <refpurpose>Create a new bus object and create or destroy references to it</refpurpose>
   </refnamediv>
@@ -46,9 +47,29 @@
         <paramdef>sd_bus *<parameter>bus</parameter></paramdef>
       </funcprototype>
 
+      <funcprototype>
+        <funcdef>sd_bus *<function>sd_bus_close_unref</function></funcdef>
+        <paramdef>sd_bus *<parameter>bus</parameter></paramdef>
+      </funcprototype>
+
+      <funcprototype>
+        <funcdef>sd_bus *<function>sd_bus_flush_close_unref</function></funcdef>
+        <paramdef>sd_bus *<parameter>bus</parameter></paramdef>
+      </funcprototype>
+
       <funcprototype>
         <funcdef>void <function>sd_bus_unrefp</function></funcdef>
-        <paramdef>sd_bus **<parameter>bus</parameter></paramdef>
+        <paramdef>sd_bus **<parameter>busp</parameter></paramdef>
+      </funcprototype>
+
+      <funcprototype>
+        <funcdef>void <function>sd_bus_close_unrefp</function></funcdef>
+        <paramdef>sd_bus **<parameter>busp</parameter></paramdef>
+      </funcprototype>
+
+      <funcprototype>
+        <funcdef>void <function>sd_bus_flush_close_unrefp</function></funcdef>
+        <paramdef>sd_bus **<parameter>busp</parameter></paramdef>
       </funcprototype>
     </funcsynopsis>
   </refsynopsisdiv>
@@ -66,14 +87,12 @@
     or a related call, and then start the connection with
     <citerefentry><refentrytitle>sd_bus_start</refentrytitle><manvolnum>3</manvolnum></citerefentry>.</para>
 
-    <para>In most cases, it is a better idea to invoke
+    <para>In most cases, it is better to use
     <citerefentry><refentrytitle>sd_bus_default_user</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
     <citerefentry><refentrytitle>sd_bus_default_system</refentrytitle><manvolnum>3</manvolnum></citerefentry>
-    or related calls instead of the more low-level
-    <function>sd_bus_new()</function> and
-    <function>sd_bus_start()</function>. The higher-level calls not
-    only allocate a bus object but also start the connection to a
-    well-known bus in a single function invocation.</para>
+    or related calls instead of the more low-level <function>sd_bus_new()</function> and
+    <function>sd_bus_start()</function>. The higher-level functions not only allocate a bus object but also
+    start the connection to a well-known bus in a single function call.</para>
 
     <para><function>sd_bus_ref()</function> increases the reference
     counter of <parameter>bus</parameter> by one.</para>
@@ -96,19 +115,41 @@
     block is left:</para>
 
     <programlisting>{
-        __attribute__((cleanup(sd_bus_unrefp)) sd_bus *bus = NULL;
-        int r;
-        …
-        r = sd_bus_default(&amp;bus);
-        if (r &lt; 0)
-                fprintf(stderr, "Failed to allocate bus: %s\n", strerror(-r));
-        …
+  __attribute__((cleanup(sd_bus_unrefp))) sd_bus *bus = NULL;
+  int r;
+  …
+  r = sd_bus_default(&amp;bus);
+  if (r &lt; 0)
+    fprintf(stderr, "Failed to allocate bus: %s\n", strerror(-r));
+  …
 }</programlisting>
 
-    <para><function>sd_bus_ref()</function>,
-    <function>sd_bus_unref()</function> and
-    <function>sd_bus_unrefp()</function> execute no operation if the
-    passed in bus object is <constant>NULL</constant>.</para>
+    <para><function>sd_bus_ref()</function> and <function>sd_bus_unref()</function>
+    execute no operation if the passed in bus object address is
+    <constant>NULL</constant>. <function>sd_bus_unrefp()</function> will first
+    dereference its argument, which must not be <constant>NULL</constant>, and will
+    execute no operation if <emphasis>that</emphasis> is <constant>NULL</constant>.
+    </para>
+
+    <para><function>sd_bus_close_unref()</function> is similar to <function>sd_bus_unref()</function>, but
+    first executes
+    <citerefentry><refentrytitle>sd_bus_close</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
+    ensuring that the connection is terminated before the reference to the connection is dropped and possibly
+    the object freed.</para>
+
+    <para><function>sd_bus_flush_close_unref()</function> is similar to <function>sd_bus_unref()</function>,
+    but first executes
+    <citerefentry><refentrytitle>sd_bus_flush</refentrytitle><manvolnum>3</manvolnum></citerefentry> as well
+    as <citerefentry><refentrytitle>sd_bus_close</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
+    ensuring that any pending messages are synchronously flushed out before the reference to the connection
+    is dropped and possibly the object freed. This call is particularly useful immediately before exiting
+    from a program as it ensures that any pending outgoing messages are written out, and unprocessed but
+    queued incoming messages released before the connection is terminated and released.</para>
+
+    <para><function>sd_bus_close_unrefp()</function> is similar to
+    <function>sd_bus_close_unref()</function>, but may be used in GCC's and LLVM's Clean-up Variable
+    Attribute, see above. Similarly, <function>sd_bus_flush_close_unrefp()</function> is similar to
+    <function>sd_bus_flush_close_unref()</function>.</para>
   </refsect1>
 
   <refsect1>
@@ -121,22 +162,22 @@
     <para><function>sd_bus_ref()</function> always returns the argument.
     </para>
 
-    <para><function>sd_bus_unref()</function> always returns
+    <para><function>sd_bus_unref()</function> and <function>sd_bus_flush_close_unref()</function> always return
     <constant>NULL</constant>.</para>
-  </refsect1>
 
-  <refsect1>
-    <title>Errors</title>
+    <refsect2>
+      <title>Errors</title>
 
-    <para>Returned errors may indicate the following problems:</para>
+      <para>Returned errors may indicate the following problems:</para>
 
-    <variablelist>
-      <varlistentry>
-        <term><constant>-ENOMEM</constant></term>
+      <variablelist>
+        <varlistentry>
+          <term><constant>-ENOMEM</constant></term>
 
-        <listitem><para>Memory allocation failed.</para></listitem>
-      </varlistentry>
-    </variablelist>
+          <listitem><para>Memory allocation failed.</para></listitem>
+        </varlistentry>
+      </variablelist>
+    </refsect2>
   </refsect1>
 
   <xi:include href="libsystemd-pkgconfig.xml" />
@@ -150,7 +191,8 @@
       <citerefentry><refentrytitle>sd_bus_default_user</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
       <citerefentry><refentrytitle>sd_bus_default_system</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
       <citerefentry><refentrytitle>sd_bus_open_user</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
-      <citerefentry><refentrytitle>sd_bus_open_system</refentrytitle><manvolnum>3</manvolnum></citerefentry>
+      <citerefentry><refentrytitle>sd_bus_open_system</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
+      <citerefentry><refentrytitle>sd_bus_close</refentrytitle><manvolnum>3</manvolnum></citerefentry>
     </para>
   </refsect1>