+ <para>It is possible (and often a very good choice) to
+ mix calls to the synchronous interface of
+ <filename>sd-login.h</filename> with the asynchronous
+ D-Bus interface of systemd-logind. However, if this is
+ done you need to think a bit about possible races
+ since the stream of events from D-Bus and from
+ <filename>sd-login.h</filename> interfaces such as the
+ login monitor are asynchronous and not ordered against
+ each other.</para>
+