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Diffstat (limited to 'man/sd_event_run.xml')
| -rw-r--r-- | man/sd_event_run.xml | 95 |
1 files changed, 51 insertions, 44 deletions
diff --git a/man/sd_event_run.xml b/man/sd_event_run.xml index 06236fcd1a..5b68959165 100644 --- a/man/sd_event_run.xml +++ b/man/sd_event_run.xml @@ -21,7 +21,7 @@ along with systemd; If not, see <http://www.gnu.org/licenses/>. --> -<refentry id="sd_event_run"> +<refentry id="sd_event_run" xmlns:xi="http://www.w3.org/2001/XInclude"> <refentryinfo> <title>sd_event_run</title> @@ -46,7 +46,7 @@ <refname>sd_event_run</refname> <refname>sd_event_loop</refname> - <refpurpose>Run the libsystemd event loop</refpurpose> + <refpurpose>Run an event loop</refpurpose> </refnamediv> <refsynopsisdiv> @@ -56,7 +56,7 @@ <funcprototype> <funcdef>int <function>sd_event_run</function></funcdef> <paramdef>sd_event *<parameter>event</parameter></paramdef> - <paramdef>uint64_t <parameter>timeout</parameter></paramdef> + <paramdef>uint64_t <parameter>usec</parameter></paramdef> </funcprototype> <funcprototype> @@ -69,47 +69,60 @@ <refsect1> <title>Description</title> - <para><function>sd_event_run()</function> can be used to run one - iteration of the event loop of libsystemd. This function waits - until an event to process is available, and dispatches a handler - for it. The <parameter>timeout</parameter> parameter specifices the - maximum time (in microseconds) to wait. <constant>(uint64_t) - -1</constant> may be used to specify an infinite timeout.</para> - - <para><function>sd_event_loop</function> runs - <function>sd_event_wait</function> in a loop with a timeout of - infinity. This makes it suitable for the main event loop of a - program.</para> + <para><function>sd_event_run()</function> may be used to run a single + iteration of the event loop specified in the + <parameter>event</parameter> parameter. The function waits until an event to + process is available, and dispatches the registered handler for + it. The <parameter>usec</parameter> parameter specifies the + maximum time (in microseconds) to wait for an event. Use + <constant>(uint64_t) -1</constant> to specify an infinite + timeout.</para> + + <para><function>sd_event_loop()</function> invokes + <function>sd_event_run()</function> in a loop, thus implementing + the actual event loop. The call returns as soon as exiting was + requested using + <citerefentry><refentrytitle>sd_event_exit</refentrytitle><manvolnum>3</manvolnum></citerefentry>.</para> <para>The event loop object <parameter>event</parameter> is created with - <function>sd_event_new</function>. - Events to wait for and their handlers can be registered with - <function>sd_event_add_time</function>, - <function>sd_event_add_child</function>, - <function>sd_event_add_signal</function>, - <function>sd_event_add_defer</function>, - <function>sd_event_add_exit</function>, + <citerefentry><refentrytitle>sd_event_new</refentrytitle><manvolnum>3</manvolnum></citerefentry>. + Events sources to wait for and their handlers may be registered + 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>, + <citerefentry><refentrytitle>sd_event_add_defer</refentrytitle><manvolnum>3</manvolnum></citerefentry>, + <citerefentry><refentrytitle>sd_event_add_post</refentrytitle><manvolnum>3</manvolnum></citerefentry> and - <function>sd_event_add_post</function>. + <citerefentry><refentrytitle>sd_event_add_exit</refentrytitle><manvolnum>3</manvolnum></citerefentry>. </para> - <para>For more fine-grained control, - <function>sd_event_prepare</function>, - <function>sd_event_wait</function>, and - <function>sd_event_dispatch</function> may be used. Along with - <function>sd_event_get_fd</function>, those functions make it - possible to integrate the libsystemd loop inside of another event - loop.</para> + <para>For low-level control of event loop execution, use + <citerefentry><refentrytitle>sd_event_prepare</refentrytitle><manvolnum>3</manvolnum></citerefentry>, + <citerefentry><refentrytitle>sd_event_wait</refentrytitle><manvolnum>3</manvolnum></citerefentry> + and + <citerefentry><refentrytitle>sd_event_dispatch</refentrytitle><manvolnum>3</manvolnum></citerefentry> + which are wrapped by <function>sd_event_run()</function>. Along + with + <citerefentry><refentrytitle>sd_event_get_fd</refentrytitle><manvolnum>3</manvolnum></citerefentry>, + these functions allow integration of an + <citerefentry><refentrytitle>sd-event</refentrytitle><manvolnum>3</manvolnum></citerefentry> + event loop into foreign event loop implementations.</para> </refsect1> <refsect1> <title>Return Value</title> - <para>On success, these functions return 0 or a positive integer. - On failure, they return a negative errno-style error code. - <function>sd_event_run</function> returns 0 if the event loop is - finished, and a positive value if it can be continued.</para> + <para>On failure, these functions return a negative errno-style + error code. <function>sd_event_run()</function> returns a + positive, non-zero integer if an event source was dispatched, and + zero when the specified timeout hit before an event source has + seen any event, and hence no event source was + dispatched. <function>sd_event_loop()</function> returns the exit + code specified when invoking + <function>sd_event_exit()</function>.</para> </refsect1> <refsect1> @@ -122,7 +135,7 @@ <term><constant>-EINVAL</constant></term> <listitem><para>The <parameter>event</parameter> parameter is - <constant>NULL</constant>.</para></listitem> + invalid or <constant>NULL</constant>.</para></listitem> </varlistentry> <varlistentry> @@ -153,15 +166,7 @@ <para>Other errors are possible, too.</para> </refsect1> - <refsect1> - <title>Notes</title> - - <para><function>sd_event_run()</function> and - <function>sd_event_loop()</function> 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> - </refsect1> + <xi:include href="libsystemd-pkgconfig.xml" /> <refsect1> <title>See Also</title> @@ -169,13 +174,15 @@ <para> <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>, <citerefentry><refentrytitle>sd_event_new</refentrytitle><manvolnum>3</manvolnum></citerefentry>, - <citerefentry><refentrytitle>sd_event_wait</refentrytitle><manvolnum>3</manvolnum></citerefentry>, <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_defer</refentrytitle><manvolnum>3</manvolnum></citerefentry>, <citerefentry><refentrytitle>sd_event_add_exit</refentrytitle><manvolnum>3</manvolnum></citerefentry>, <citerefentry><refentrytitle>sd_event_add_post</refentrytitle><manvolnum>3</manvolnum></citerefentry>, + <citerefentry><refentrytitle>sd_event_exit</refentrytitle><manvolnum>3</manvolnum></citerefentry>, + <citerefentry><refentrytitle>sd_event_get_fd</refentrytitle><manvolnum>3</manvolnum></citerefentry>, + <citerefentry><refentrytitle>sd_event_wait</refentrytitle><manvolnum>3</manvolnum></citerefentry>, <ulink url="https://developer.gnome.org/glib/unstable/glib-The-Main-Event-Loop.html">GLib Main Event Loop</ulink>. </para> </refsect1> |