man-pages/man3/sd_event_run.3.html
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<H1>SD_EVENT_RUN</H1>
Section: sd_event_run (3)<BR>Updated: <BR><A HREF="#index">Index</A>
<A HREF="/cgi-bin/man/man2html">Return to Main Contents</A><HR>
<A NAME="lbAB">&nbsp;</A>
<H2>NAME</H2>
sd_event_run, sd_event_loop - Run an event loop
<A NAME="lbAC">&nbsp;</A>
<H2>SYNOPSIS</H2>
<P>
<B>
</B><PRE>
#include &lt;<A HREF="file:///usr/include/systemd/sd-event.h">systemd/sd-event.h</A>&gt;
</PRE>
<DL COMPACT>
<DT id="1">
<B>int sd_event_run(sd_event&nbsp;*</B><I>event</I><B>, uint64_t&nbsp;</B><I>usec</I><B>);</B>
<DT id="2">
<B>int sd_event_loop(sd_event&nbsp;*</B><I>event</I><B>);</B>
</DL>
<A NAME="lbAD">&nbsp;</A>
<H2>DESCRIPTION</H2>
<P>
<B>sd_event_run()</B>
<DD>may be used to run a single iteration of the event loop specified in the
<I>event</I>
parameter. The function waits until an event to process is available, and dispatches the registered handler for it. The
<I>usec</I>
parameter specifies the maximum time (in microseconds) to wait for an event. Use
<B>(uint64_t) -1</B>
to specify an infinite timeout.
<P>
<B>sd_event_loop()</B>
invokes
<B>sd_event_run()</B>
in a loop, thus implementing the actual event loop. The call returns as soon as exiting was requested using
<B><A HREF="/cgi-bin/man/man2html?3+sd_event_exit">sd_event_exit</A></B>(3).
<P>
The event loop object
<I>event</I>
is created with
<B><A HREF="/cgi-bin/man/man2html?3+sd_event_new">sd_event_new</A></B>(3). Events sources to wait for and their handlers may be registered with
<B><A HREF="/cgi-bin/man/man2html?3+sd_event_add_io">sd_event_add_io</A></B>(3),
<B><A HREF="/cgi-bin/man/man2html?3+sd_event_add_time">sd_event_add_time</A></B>(3),
<B><A HREF="/cgi-bin/man/man2html?3+sd_event_add_signal">sd_event_add_signal</A></B>(3),
<B><A HREF="/cgi-bin/man/man2html?3+sd_event_add_child">sd_event_add_child</A></B>(3),
<B><A HREF="/cgi-bin/man/man2html?3+sd_event_add_defer">sd_event_add_defer</A></B>(3),
<B><A HREF="/cgi-bin/man/man2html?3+sd_event_add_post">sd_event_add_post</A></B>(3)
and
<B><A HREF="/cgi-bin/man/man2html?3+sd_event_add_exit">sd_event_add_exit</A></B>(3).
<P>
For low-level control of event loop execution, use
<B><A HREF="/cgi-bin/man/man2html?3+sd_event_prepare">sd_event_prepare</A></B>(3),
<B><A HREF="/cgi-bin/man/man2html?3+sd_event_wait">sd_event_wait</A></B>(3)
and
<B><A HREF="/cgi-bin/man/man2html?3+sd_event_dispatch">sd_event_dispatch</A></B>(3)
which are wrapped by
<B>sd_event_run()</B>. Along with
<B><A HREF="/cgi-bin/man/man2html?3+sd_event_get_fd">sd_event_get_fd</A></B>(3), these functions allow integration of an
<B><A HREF="/cgi-bin/man/man2html?3+sd-event">sd-event</A></B>(3)
event loop into foreign event loop implementations.
<A NAME="lbAE">&nbsp;</A>
<H2>RETURN VALUE</H2>
<P>
On failure, these functions return a negative errno-style error code.
<B>sd_event_run()</B>
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.
<B>sd_event_loop()</B>
returns the exit code specified when invoking
<B>sd_event_exit()</B>.
<A NAME="lbAF">&nbsp;</A>
<H3>Errors</H3>
<P>
Returned errors may indicate the following problems:
<P>
<B>-EINVAL</B>
<DL COMPACT><DT id="3"><DD>
The
<I>event</I>
parameter is invalid or
<B>NULL</B>.
</DL>
<P>
<B>-EBUSY</B>
<DL COMPACT><DT id="4"><DD>
The event loop object is not in the right state (see
<B><A HREF="/cgi-bin/man/man2html?3+sd_event_prepare">sd_event_prepare</A></B>(3)
for an explanation of possible states).
</DL>
<P>
<B>-ESTALE</B>
<DL COMPACT><DT id="5"><DD>
The event loop is already terminated.
</DL>
<P>
<B>-ECHILD</B>
<DL COMPACT><DT id="6"><DD>
The event loop has been created in a different process.
</DL>
<P>
Other errors are possible, too.
<A NAME="lbAG">&nbsp;</A>
<H2>NOTES</H2>
<P>
These APIs are implemented as a shared library, which can be compiled and linked to with the
<B>libsystemd</B>&nbsp;<B><A HREF="/cgi-bin/man/man2html?1+pkg-config">pkg-config</A></B>(1)
file.
<A NAME="lbAH">&nbsp;</A>
<H2>SEE ALSO</H2>
<P>
<B><A HREF="/cgi-bin/man/man2html?1+systemd">systemd</A></B>(1),
<B><A HREF="/cgi-bin/man/man2html?3+sd-event">sd-event</A></B>(3),
<B><A HREF="/cgi-bin/man/man2html?3+sd_event_new">sd_event_new</A></B>(3),
<B><A HREF="/cgi-bin/man/man2html?3+sd_event_add_io">sd_event_add_io</A></B>(3),
<B><A HREF="/cgi-bin/man/man2html?3+sd_event_add_time">sd_event_add_time</A></B>(3),
<B><A HREF="/cgi-bin/man/man2html?3+sd_event_add_signal">sd_event_add_signal</A></B>(3),
<B><A HREF="/cgi-bin/man/man2html?3+sd_event_add_child">sd_event_add_child</A></B>(3),
<B><A HREF="/cgi-bin/man/man2html?3+sd_event_add_inotify">sd_event_add_inotify</A></B>(3),
<B><A HREF="/cgi-bin/man/man2html?3+sd_event_add_defer">sd_event_add_defer</A></B>(3),
<B><A HREF="/cgi-bin/man/man2html?3+sd_event_exit">sd_event_exit</A></B>(3),
<B><A HREF="/cgi-bin/man/man2html?3+sd_event_get_fd">sd_event_get_fd</A></B>(3),
<B><A HREF="/cgi-bin/man/man2html?3+sd_event_wait">sd_event_wait</A></B>(3),
m[blue]<B>GLib Main Event Loop</B>m[]<FONT SIZE="-2">[1]</FONT>
<A NAME="lbAI">&nbsp;</A>
<H2>NOTES</H2>
<DL COMPACT>
<DT id="7"> 1.<DD>
GLib Main Event Loop
<DL COMPACT><DT id="8"><DD>
<A HREF="https://developer.gnome.org/glib/unstable/glib-The-Main-Event-Loop.html">https://developer.gnome.org/glib/unstable/glib-The-Main-Event-Loop.html</A>
</DL>
<P>
</DL>
<HR>
<A NAME="index">&nbsp;</A><H2>Index</H2>
<DL>
<DT id="9"><A HREF="#lbAB">NAME</A><DD>
<DT id="10"><A HREF="#lbAC">SYNOPSIS</A><DD>
<DT id="11"><A HREF="#lbAD">DESCRIPTION</A><DD>
<DT id="12"><A HREF="#lbAE">RETURN VALUE</A><DD>
<DL>
<DT id="13"><A HREF="#lbAF">Errors</A><DD>
</DL>
<DT id="14"><A HREF="#lbAG">NOTES</A><DD>
<DT id="15"><A HREF="#lbAH">SEE ALSO</A><DD>
<DT id="16"><A HREF="#lbAI">NOTES</A><DD>
</DL>
<HR>
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Time: 00:05:55 GMT, March 31, 2021
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