diff options
Diffstat (limited to 'man/sd_bus_wait.xml')
| -rw-r--r-- | man/sd_bus_wait.xml | 118 |
1 files changed, 118 insertions, 0 deletions
diff --git a/man/sd_bus_wait.xml b/man/sd_bus_wait.xml new file mode 100644 index 0000000..04dd090 --- /dev/null +++ b/man/sd_bus_wait.xml @@ -0,0 +1,118 @@ +<?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 + + Copyright © 2016 Julian Orth +--> + +<refentry id="sd_bus_wait" xmlns:xi="http://www.w3.org/2001/XInclude"> + + <refentryinfo> + <title>sd_bus_wait</title> + <productname>systemd</productname> + </refentryinfo> + + <refmeta> + <refentrytitle>sd_bus_wait</refentrytitle> + <manvolnum>3</manvolnum> + </refmeta> + + <refnamediv> + <refname>sd_bus_wait</refname> + + <refpurpose>Wait for I/O on a bus connection</refpurpose> + </refnamediv> + + <refsynopsisdiv> + <funcsynopsis> + <funcsynopsisinfo>#include <systemd/sd-bus.h></funcsynopsisinfo> + + <funcprototype> + <funcdef>int <function>sd_bus_wait</function></funcdef> + <paramdef>sd_bus *<parameter>bus</parameter></paramdef> + <paramdef>uint64_t <parameter>timeout_usec</parameter></paramdef> + </funcprototype> + </funcsynopsis> + </refsynopsisdiv> + + <refsect1> + <title>Description</title> + + <para><function>sd_bus_wait()</function> synchronously waits for I/O on the specified bus connection object. This + function is supposed to be called whenever + <citerefentry><refentrytitle>sd_bus_process</refentrytitle><manvolnum>3</manvolnum></citerefentry> returns zero, + indicating that no work is pending on the connection. Internally, this call invokes <citerefentry + project='man-pages'><refentrytitle>ppoll</refentrytitle><manvolnum>2</manvolnum></citerefentry>, to wait for I/O on + the bus connection. If the <parameter>timeout_usec</parameter> parameter is specified, the call will block at most + for the specified amount of time in μs. Pass <constant>UINT64_MAX</constant> to permit it to sleep + indefinitely.</para> + + <para>After each invocation of <function>sd_bus_wait()</function> the <function>sd_bus_process()</function> call + should be invoked in order to process any now pending I/O work.</para> + + <para>Note that <function>sd_bus_wait()</function> is suitable only for simple programs as it does not permit + waiting for other I/O events. For more complex programs either connect the bus connection object to an external + event loop using <citerefentry><refentrytitle>sd_bus_get_fd</refentrytitle><manvolnum>3</manvolnum></citerefentry> + or to an <citerefentry><refentrytitle>sd-event</refentrytitle><manvolnum>3</manvolnum></citerefentry> event loop + using + <citerefentry><refentrytitle>sd_bus_attach_event</refentrytitle><manvolnum>3</manvolnum></citerefentry>.</para> + </refsect1> + + <refsect1> + <title>Return Value</title> + + <para>If any I/O was seen, a positive value is returned, zero otherwise. If an error occurs, a negative + <varname>errno</varname>-style error code is returned.</para> + + <refsect2> + <title>Errors</title> + + <para>Returned errors may indicate the following problems:</para> + + <variablelist> + <varlistentry> + <term><constant>-EINVAL</constant></term> + + <listitem><para>An invalid bus object was passed.</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></listitem> + </varlistentry> + + <varlistentry> + <term><constant>-ENOTCONN</constant></term> + + <listitem><para>The bus connection has been terminated already.</para></listitem> + </varlistentry> + </variablelist> + </refsect2> + </refsect1> + + <xi:include href="libsystemd-pkgconfig.xml" /> + + <refsect1> + <title>History</title> + <para><function>sd_bus_wait()</function> was added in version 240.</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_process</refentrytitle><manvolnum>3</manvolnum></citerefentry>, + <citerefentry><refentrytitle>sd_bus_get_fd</refentrytitle><manvolnum>3</manvolnum></citerefentry>, + <citerefentry><refentrytitle>sd-event</refentrytitle><manvolnum>3</manvolnum></citerefentry>, + <citerefentry><refentrytitle>sd_bus_attach_event</refentrytitle><manvolnum>3</manvolnum></citerefentry> + </para> + </refsect1> + +</refentry> |