diff options
Diffstat (limited to 'man/sd_event_new.xml')
| -rw-r--r-- | man/sd_event_new.xml | 102 |
1 files changed, 83 insertions, 19 deletions
diff --git a/man/sd_event_new.xml b/man/sd_event_new.xml index e5a440556e..2c23b00a8c 100644 --- a/man/sd_event_new.xml +++ b/man/sd_event_new.xml @@ -21,7 +21,7 @@ along with systemd; If not, see <http://www.gnu.org/licenses/>. --> -<refentry id="sd_event_new"> +<refentry id="sd_event_new" xmlns:xi="http://www.w3.org/2001/XInclude"> <refentryinfo> <title>sd_event_new</title> @@ -47,32 +47,48 @@ <refname>sd_event_default</refname> <refname>sd_event_ref</refname> <refname>sd_event_unref</refname> + <refname>sd_event_unrefp</refname> + <refname>sd_event_get_tid</refname> + <refname>sd_event</refname> <refpurpose>Acquire and release an event loop object</refpurpose> </refnamediv> <refsynopsisdiv> <funcsynopsis> - <funcsynopsisinfo>#include <systemd/sd-bus.h></funcsynopsisinfo> + <funcsynopsisinfo>#include <systemd/sd-event.h></funcsynopsisinfo> + + <funcsynopsisinfo><token>typedef</token> struct sd_event sd_event;</funcsynopsisinfo> <funcprototype> <funcdef>int <function>sd_event_new</function></funcdef> - <paramdef>sd_bus **<parameter>event</parameter></paramdef> + <paramdef>sd_event **<parameter>event</parameter></paramdef> </funcprototype> <funcprototype> <funcdef>int <function>sd_event_default</function></funcdef> - <paramdef>sd_bus **<parameter>event</parameter></paramdef> + <paramdef>sd_event **<parameter>event</parameter></paramdef> </funcprototype> <funcprototype> - <funcdef>sd_bus *<function>sd_event_ref</function></funcdef> - <paramdef>sd_bus *<parameter>event</parameter></paramdef> + <funcdef>sd_event *<function>sd_event_ref</function></funcdef> + <paramdef>sd_event *<parameter>event</parameter></paramdef> </funcprototype> <funcprototype> - <funcdef>sd_bus *<function>sd_event_unref</function></funcdef> - <paramdef>sd_bus *<parameter>event</parameter></paramdef> + <funcdef>sd_event *<function>sd_event_unref</function></funcdef> + <paramdef>sd_event *<parameter>event</parameter></paramdef> + </funcprototype> + + <funcprototype> + <funcdef>void <function>sd_event_unrefp</function></funcdef> + <paramdef>sd_event **<parameter>event</parameter></paramdef> + </funcprototype> + + <funcprototype> + <funcdef>int <function>sd_event_get_tid</function></funcdef> + <paramdef>sd_event *<parameter>event</parameter></paramdef> + <paramdef>pid_t *<parameter>tid</parameter></paramdef> </funcprototype> </funcsynopsis> @@ -103,6 +119,17 @@ thread. All threads have exactly either zero or one default event loop objects associated, but never more.</para> + <para>After allocating an event loop object, add event sources to + it with + <citerefentry><refentrytitle>sd_event_add_io</refentrytitle><manvolnum>3</manvolnum></citerefentry>, + <citerefentry><refentrytitle>sd_event_add_time</refentrytitle><manvolnum>3</manvolnum></citerefentry>, + <citerefentry><refentrytitle>sd_event_add_signal</refentrytitle><manvolnum>3</manvolnum></citerefentry>, + <citerefentry><refentrytitle>sd_event_add_child</refentrytitle><manvolnum>3</manvolnum></citerefentry> + or + <citerefentry><refentrytitle>sd_event_add_defer</refentrytitle><manvolnum>3</manvolnum></citerefentry>, + and then execute the event loop using + <citerefentry><refentrytitle>sd_event_run</refentrytitle><manvolnum>3</manvolnum></citerefentry>.</para> + <para><function>sd_event_ref()</function> increases the reference count of the specified event loop object by one.</para> @@ -114,9 +141,43 @@ <function>sd_event_default()</function>, then releasing it, and then acquiring a new one with <function>sd_event_default()</function> will result in two - distinct objects. Note that in order to free an event loop object, + distinct objects. Note that, in order to free an event loop object, all remaining event sources of the event loop also need to be freed as each keeps a reference to it.</para> + + <para><function>sd_event_unrefp()</function> is similar to + <function>sd_event_unref()</function> but takes a pointer to a + pointer to an <type>sd_event</type> object. This call is useful in + conjunction with GCC's and LLVM's <ulink + url="https://gcc.gnu.org/onlinedocs/gcc/Common-Variable-Attributes.html">Clean-up + Variable Attribute</ulink>. Note that this function is defined as + inline function. Use a declaration like the following, + in order to allocate an event loop object that is freed + automatically as the code block is left:</para> + + <programlisting>{ + __attribute__((cleanup(sd_event_unrefp)) sd_event *event = NULL; + int r; + … + r = sd_event_default(&event); + if (r < 0) + fprintf(stderr, "Failed to allocate event loop: %s\n", strerror(-r)); + … +}</programlisting> + + <para><function>sd_event_ref()</function>, + <function>sd_event_unref()</function> and + <function>sd_event_unrefp()</function> execute no operation if the + passed in event loop object is <constant>NULL</constant>.</para> + + <para><function>sd_event_get_tid()</function> retrieves the thread + identifier ("TID") of the thread the specified event loop object + is associated with. This call is only supported for event loops + allocated with <function>sd_event_default()</function>, and + returns the identifier for the thread the event loop is the + default event loop of. See <citerefentry + project='man-pages'><refentrytitle>gettid</refentrytitle><manvolnum>2</manvolnum></citerefentry> + for more information on thread identifiers.</para> </refsect1> <refsect1> @@ -149,19 +210,20 @@ <listitem><para>The maximum number of event loops has been allocated.</para></listitem> </varlistentry> - </variablelist> - </refsect1> - <refsect1> - <title>Notes</title> + <varlistentry> + <term><constant>-ENXIO</constant></term> - <para><function>sd_event_new()</function> and the other functions - described here are available as a shared library, which can be - compiled and linked to with the - <constant>libsystemd</constant> <citerefentry project='die-net'><refentrytitle>pkg-config</refentrytitle><manvolnum>1</manvolnum></citerefentry> - file.</para> + <listitem><para><function>sd_event_get_tid()</function> was + invoked on an event loop object that was not allocated with + <function>sd_event_default()</function>.</para></listitem> + </varlistentry> + + </variablelist> </refsect1> + <xi:include href="libsystemd-pkgconfig.xml" /> + <refsect1> <title>See Also</title> @@ -174,7 +236,9 @@ <citerefentry><refentrytitle>sd_event_add_child</refentrytitle><manvolnum>3</manvolnum></citerefentry>, <citerefentry><refentrytitle>sd_event_add_defer</refentrytitle><manvolnum>3</manvolnum></citerefentry>, <citerefentry><refentrytitle>sd_event_add_post</refentrytitle><manvolnum>3</manvolnum></citerefentry>, - <citerefentry><refentrytitle>sd_event_add_exit</refentrytitle><manvolnum>3</manvolnum></citerefentry> + <citerefentry><refentrytitle>sd_event_add_exit</refentrytitle><manvolnum>3</manvolnum></citerefentry>, + <citerefentry><refentrytitle>sd_event_run</refentrytitle><manvolnum>3</manvolnum></citerefentry>, + <citerefentry project='man-pages'><refentrytitle>gettid</refentrytitle><manvolnum>2</manvolnum></citerefentry> </para> </refsect1> |