X-Git-Url: https://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=elogind.git;a=blobdiff_plain;f=man%2Fsd_login_monitor_new.xml;h=b187ad0dbe9536d2e9adf4558849be97bd5d2f3e;hp=35cb6b368b28ab326210c9f645d37a0c1abbee55;hb=667c24a6a86a5a26a906b7477ae81dcf4c73e64e;hpb=f274ece0f76b5709408821e317e87aef76123db6

diff --git a/man/sd_login_monitor_new.xml b/man/sd_login_monitor_new.xml
index 35cb6b368..b187ad0db 100644
--- a/man/sd_login_monitor_new.xml
+++ b/man/sd_login_monitor_new.xml
@@ -21,7 +21,7 @@
   along with systemd; If not, see <http://www.gnu.org/licenses/>.
 -->
 
-<refentry id="sd_login_monitor_new">
+<refentry id="sd_login_monitor_new" conditional='HAVE_PAM'>
 
         <refentryinfo>
                 <title>sd_login_monitor_new</title>
@@ -47,6 +47,8 @@
                 <refname>sd_login_monitor_unref</refname>
                 <refname>sd_login_monitor_flush</refname>
                 <refname>sd_login_monitor_get_fd</refname>
+                <refname>sd_login_monitor_get_events</refname>
+                <refname>sd_login_monitor_get_timeout</refname>
                 <refname>sd_login_monitor</refname>
                 <refpurpose>Monitor login sessions, seats and users</refpurpose>
         </refnamediv>
@@ -76,6 +78,17 @@
                                 <paramdef>sd_login_monitor* <parameter>m</parameter></paramdef>
                         </funcprototype>
 
+                        <funcprototype>
+                                <funcdef>int <function>sd_login_monitor_get_events</function></funcdef>
+                                <paramdef>sd_login_monitor* <parameter>m</parameter></paramdef>
+                        </funcprototype>
+
+                        <funcprototype>
+                                <funcdef>int <function>sd_login_monitor_get_timeout</function></funcdef>
+                                <paramdef>sd_login_monitor* <parameter>m</parameter></paramdef>
+                                <paramdef>uint64_t* <parameter>timeout_usec</parameter></paramdef>
+                        </funcprototype>
+
                 </funcsynopsis>
         </refsynopsisdiv>
 
@@ -122,26 +135,78 @@
                 application defined event loop, based around
                 <citerefentry><refentrytitle>poll</refentrytitle><manvolnum>2</manvolnum></citerefentry>
                 or a similar interface. The application should include
-                the returned file descriptor as wake up source for
-                POLLIN events. Whenever a wake-up is triggered the
-                file descriptor needs to be reset via
+                the returned file descriptor as wake-up source for the
+                events mask returned by
+                <function>sd_login_monitor_get_events()</function>. It
+                should pass a timeout value as returned by
+                <function>sd_login_monitor_get_timeout()</function>. Whenever
+                a wake-up is triggered the file descriptor needs to be
+                reset via
                 <function>sd_login_monitor_flush()</function>. An
                 application needs to reread the login state with a
                 function like
                 <citerefentry><refentrytitle>sd_get_seats</refentrytitle><manvolnum>3</manvolnum></citerefentry>
                 or similar to determine what changed.</para>
+
+                <para><function>sd_login_monitor_get_events()</function>
+                will return the <function>poll()</function> mask to
+                wait for. This function will return a combination of
+                <literal>POLLIN</literal>, <literal>POLLOUT</literal>
+                and similar to fill into the
+                <literal>.events</literal> field of <literal>struct
+                pollfd</literal>.</para>
+
+                <para><function>sd_login_monitor_get_timeout()</function>
+                will return a timeout value for usage in
+                <function>poll()</function>. This returns a value in
+                microseconds since the epoch of CLOCK_MONOTONIC for
+                timing out <function>poll()</function> in
+                <literal>timeout_usec</literal>. See
+                <citerefentry><refentrytitle>clock_gettime</refentrytitle><manvolnum>2</manvolnum></citerefentry>
+                for details about
+                <literal>CLOCK_MONOTONIC</literal>. If there's no
+                timeout to wait for this will fill in
+                <literal>(uint64_t) -1</literal> instead. Note that
+                <function>poll()</function> takes a relative timeout
+                in milliseconds rather than an absolute timeout in
+                microseconds. To convert the absolute 'us' timeout into
+                relative 'ms', use code like the following:</para>
+
+                <programlisting>uint64_t t;
+int msec;
+sd_login_monitor_get_timeout(m, &amp;t);
+if (t == (uint64_t) -1)
+        msec = -1;
+else {
+        struct timespec ts;
+        uint64_t n;
+        clock_getttime(CLOCK_MONOTONIC, &amp;ts);
+        n = (uint64_t) ts.tv_sec * 1000000 + ts.tv_nsec / 1000;
+        msec = t > n ? (int) ((t - n + 999) / 1000) : 0;
+}</programlisting>
+
+                <para>The code above does not do any error checking
+                for brevity's sake. The calculated <literal>msec</literal>
+                integer can be passed directly as
+                <function>poll()</function>'s timeout
+                parameter.</para>
         </refsect1>
 
         <refsect1>
                 <title>Return Value</title>
 
                 <para>On success
-                <function>sd_login_monitor_new()</function> and
-                <function>sd_login_monitor_flush()</function> return 0
-                or a positive integer. On success
+                <function>sd_login_monitor_new()</function>,
+                <function>sd_login_monitor_flush()</function> and
+                <function>sd_login_monitor_get_timeout()</function>
+                return 0 or a positive integer. On success
                 <function>sd_login_monitor_get_fd()</function> returns
-                a Unix file descriptor. On failure, these calls return
-                a negative errno-style error code.</para>
+                a Unix file descriptor. On success
+                <function>sd_login_monitor_get_events()</function>
+                returns a combination of <literal>POLLIN</literal>,
+                <literal>POLLOUT</literal> and suchlike. On failure,
+                these calls return a negative errno-style error
+                code.</para>
 
                 <para><function>sd_login_monitor_unref()</function>
                 always returns NULL.</para>
@@ -151,10 +216,13 @@
                 <title>Notes</title>
 
                 <para>The <function>sd_login_monitor_new()</function>,
-                <function>sd_login_monitor_unref()</function>, <function>sd_login_monitor_flush()</function> and
-                <function>sd_login_monitor_get_fd()</function> interfaces
-                are available as shared library, which can be compiled
-                and linked to with the
+                <function>sd_login_monitor_unref()</function>,
+                <function>sd_login_monitor_flush()</function>,
+                <function>sd_login_monitor_get_fd()</function>,
+                <function>sd_login_monitor_get_events()</function> and
+                <function>sd_login_monitor_get_timeout()</function>
+                interfaces are available as shared library, which can
+                be compiled and linked to with the
                 <literal>libsystemd-login</literal>
                 <citerefentry><refentrytitle>pkg-config</refentrytitle><manvolnum>1</manvolnum></citerefentry>
                 file.</para>
@@ -166,7 +234,9 @@
                 <para>
                         <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
                         <citerefentry><refentrytitle>sd-login</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
-                        <citerefentry><refentrytitle>sd_get_seats</refentrytitle><manvolnum>3</manvolnum></citerefentry>
+                        <citerefentry><refentrytitle>sd_get_seats</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
+                        <citerefentry><refentrytitle>poll</refentrytitle><manvolnum>2</manvolnum></citerefentry>,
+                        <citerefentry><refentrytitle>clock_gettime</refentrytitle><manvolnum>2</manvolnum></citerefentry>
                 </para>
         </refsect1>