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| <!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_event_set_signal_exit" xmlns:xi="http://www.w3.org/2001/XInclude"> |
| |
| <refentryinfo> |
| <title>sd_event_set_signal_exit</title> |
| <productname>systemd</productname> |
| </refentryinfo> |
| |
| <refmeta> |
| <refentrytitle>sd_event_set_signal_exit</refentrytitle> |
| <manvolnum>3</manvolnum> |
| </refmeta> |
| |
| <refnamediv> |
| <refname>sd_event_set_signal_exit</refname> |
| |
| <refpurpose>Automatically leave event loop on <constant>SIGINT</constant> and <constant>SIGTERM</constant></refpurpose> |
| </refnamediv> |
| |
| <refsynopsisdiv> |
| <funcsynopsis> |
| <funcsynopsisinfo>#include <systemd/sd-event.h></funcsynopsisinfo> |
| |
| <funcprototype> |
| <funcdef>int <function>sd_event_set_signal_exit</function></funcdef> |
| <paramdef>sd_event *<parameter>event</parameter></paramdef> |
| <paramdef>int b</paramdef> |
| </funcprototype> |
| |
| </funcsynopsis> |
| </refsynopsisdiv> |
| |
| <refsect1> |
| <title>Description</title> |
| |
| <para><function>sd_event_set_signal_exit()</function> may be used to ensure the event loop terminates |
| once a <constant>SIGINT</constant> or <constant>SIGTERM</constant> signal is received. It is a |
| convencience wrapper around invocations of |
| <citerefentry><refentrytitle>sd_event_add_signal</refentrytitle><manvolnum>3</manvolnum></citerefentry> |
| for both signals. The two signals are automatically added to the calling thread's signal mask (if a |
| program is multi-threaded care should be taken to either invoke this function before the first thread is |
| started or to manually block the two signals process-wide first).</para> |
| |
| <para>If the parameter <parameter>b</parameter> is specified as true, the event loop will terminate on |
| <constant>SIGINT</constant> and <constant>SIGTERM</constant>. If specified as false, it will no |
| longer. When this functionality is turned off the calling thread's signal mask is restored to match the |
| state before it was turned on, for the two signals. By default the two signals are not handled by the |
| event loop, and Linux' default signal handling for them is in effect.</para> |
| |
| <para>It's customary for UNIX programs to exit on either of these two signals, hence it's typically a |
| good idea to enable this functionality for the main event loop of a program.</para> |
| </refsect1> |
| |
| <refsect1> |
| <title>Return Value</title> |
| |
| <para><function>sd_event_set_signal_exit()</function> returns a positive non-zero value when the setting |
| was successfully changed. It returns a zero when the specified setting was already in effect. On failure, |
| it returns a negative errno-style error code.</para> |
| |
| <refsect2> |
| <title>Errors</title> |
| |
| <para>Returned errors may indicate the following problems:</para> |
| |
| <variablelist> |
| |
| <varlistentry> |
| <term><constant>-ECHILD</constant></term> |
| |
| <listitem><para>The event loop has been created in a different process.</para></listitem> |
| </varlistentry> |
| |
| <varlistentry> |
| <term><constant>-EINVAL</constant></term> |
| |
| <listitem><para>The passed event loop object was invalid.</para></listitem> |
| </varlistentry> |
| |
| </variablelist> |
| </refsect2> |
| </refsect1> |
| |
| <xi:include href="libsystemd-pkgconfig.xml" /> |
| |
| <refsect1> |
| <title>See Also</title> |
| |
| <para> |
| <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>, |
| <citerefentry><refentrytitle>sd-event</refentrytitle><manvolnum>3</manvolnum></citerefentry>, |
| <citerefentry><refentrytitle>sd_event_new</refentrytitle><manvolnum>3</manvolnum></citerefentry>, |
| <citerefentry><refentrytitle>sd_event_add_signal</refentrytitle><manvolnum>3</manvolnum></citerefentry> |
| </para> |
| </refsect1> |
| |
| </refentry> |