dbus/doc dbus-tutorial.xml,1.2,1.3
Havoc Pennington
hp@pdx.freedesktop.org
Thu, 02 Oct 2003 15:49:13 -0700
Update of /cvs/dbus/dbus/doc
In directory pdx:/tmp/cvs-serv11820/doc
Modified Files:
dbus-tutorial.xml
Log Message:
tutorial hacking
Index: dbus-tutorial.xml
===================================================================
RCS file: /cvs/dbus/dbus/doc/dbus-tutorial.xml,v
retrieving revision 1.2
retrieving revision 1.3
diff -u -d -r1.2 -r1.3
--- dbus-tutorial.xml 2 Oct 2003 22:34:17 -0000 1.2
+++ dbus-tutorial.xml 2 Oct 2003 22:49:11 -0000 1.3
@@ -65,7 +65,15 @@
</para>
<para>
- The message bus daemon has multiple instances on a typical computer. The
+ The message bus daemon forms the hub of a wheel. Each spoke of the wheel
+ is a one-to-one connection to an application using libdbus. An
+ application sends a message to the bus daemon over its spoke, and the bus
+ daemon forwards the message to other connected applications as
+ appropriate. Think of the daemon as a router.
+ </para>
+
+ <para>
+ The bus daemon has multiple instances on a typical computer. The
first instance is a machine-global singleton, that is, a system daemon
similar to sendmail or Apache. This instance has heavy security
restrictions on what messages it will accept, and is used for systemwide
@@ -306,6 +314,7 @@
each one is unique. They are created dynamically, and are never re-used
during the lifetime of the same bus daemon. You know that a given
base service name will have the same owner at all times.
+ An example of a base service name might be <literal>:34-907</literal>.
</para>
<para>
@@ -324,7 +333,15 @@
</para>
<para>
- Services have another important use, other than routing messages. They
+ You could think of the base service names as IP addresses, and the
+ well-known services as domain names. So
+ <literal>com.mycompany.TextEditor</literal> might map to something like
+ <literal>:34-907</literal> just as <literal>mycompany.com</literal> maps
+ to something like <literal>192.168.0.5</literal>.
+ </para>
+
+ <para>
+ Services have a second important use, other than routing messages. They
are used to track lifecycle. When an application exits (or crashes), its
connection to the message bus will be closed by the operating system
kernel. The message bus then sends out notification messages telling