From 487e5e7f4e7525037a1a8898787a6b4a48a0c4b3 Mon Sep 17 00:00:00 2001
From: Lennart Poettering <lennart@poettering.net>
Date: Sun, 22 Dec 2013 02:35:13 +0100
Subject: [PATCH] spec: introduce new value "const" for EmitsChangedSignal
 annotation

---
 doc/dbus-specification.xml | 19 ++++++++++++++++++-
 1 file changed, 18 insertions(+), 1 deletion(-)

diff --git a/doc/dbus-specification.xml b/doc/dbus-specification.xml
index 629ab10..bef77f8 100644
--- a/doc/dbus-specification.xml
+++ b/doc/dbus-specification.xml
@@ -3795,7 +3795,7 @@
 	   </row>
 	   <row>
 	     <entry>org.freedesktop.DBus.Property.EmitsChangedSignal</entry>
-	     <entry>true,invalidates,false</entry>
+	     <entry>true,invalidates,const,false</entry>
 	     <entry>
                <para>
                  If set to <literal>false</literal>, the
@@ -3805,6 +3805,12 @@
                  guaranteed to be emitted if the property changes.
                </para>
                <para>
+                 If set to <literal>const</literal> the property never
+                 changes value during the lifetime of the object it
+                 belongs to, and hence the signal is never emitted for
+                 it.
+               </para>
+               <para>
                  If set to <literal>invalidates</literal> the signal
                  is emitted but the value is not included in the
                  signal.
@@ -3820,6 +3826,17 @@
                  defaults to the value specified in the enclosing
                  interface element.
                </para>
+               <para>
+                 This annotation is intended to be used by code
+                 generators to implement client-side caching of
+                 property values. For all properties for which the
+                 annotation is set to <literal>const</literal>,
+                 <literal>invalidates</literal> or
+                 <literal>true</literal> the client may
+                 unconditionally cache the values as the properties
+                 don't change or notifications are generated for them
+                 if they do.
+               </para>
              </entry>
 	   </row>
 	 </tbody>
-- 
1.8.4.2