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| author | Simon McVittie <simon.mcvittie@collabora.co.uk> | 2014-09-23 17:43:30 +0100 |
|---|---|---|
| committer | Simon McVittie <simon.mcvittie@collabora.co.uk> | 2014-09-24 18:07:54 +0100 |
| commit | 5392058c25d425934ee13570d40d04acab5df832 (patch) | |
| tree | 37b4cb7ee1ff5e921f14d4d26be2dc7e1530a55c /doc | |
| parent | 529691794ee370ca30848bb853321d0a26693ef6 (diff) | |
| download | dbus-5392058c25d425934ee13570d40d04acab5df832.tar.gz | |
Expand documentation of NO_REPLY_EXPECTED
The message type is more important than whether NO_REPLY_EXPECTED is
set, when deciding whether a reply is expected. This documents
existing practice in at least libdbus, GDBus and dbus-daemon.
Bug: https://bugs.freedesktop.org/show_bug.cgi?id=75749
Reviewed-by: Thiago Macieira
Diffstat (limited to 'doc')
| -rw-r--r-- | doc/dbus-specification.xml | 34 |
1 files changed, 26 insertions, 8 deletions
diff --git a/doc/dbus-specification.xml b/doc/dbus-specification.xml index 3276f2b4..a110a083 100644 --- a/doc/dbus-specification.xml +++ b/doc/dbus-specification.xml @@ -1300,7 +1300,8 @@ <row> <entry><literal>METHOD_CALL</literal></entry> <entry>1</entry> - <entry>Method call.</entry> + <entry>Method call. This message type may prompt a + reply.</entry> </row> <row> <entry><literal>METHOD_RETURN</literal></entry> @@ -1337,11 +1338,26 @@ <row> <entry><literal>NO_REPLY_EXPECTED</literal></entry> <entry>0x1</entry> - <entry>This message does not expect method return replies or - error replies; the reply can be omitted as an - optimization. However, it is compliant with this specification - to return the reply despite this flag and the only harm - from doing so is extra network traffic. + <entry> + <para> + This message does not expect method return replies or + error replies, even if it is of a type that can + have a reply; the reply can be omitted as an + optimization. It is compliant with this specification + to return the reply despite this flag, although doing + so on a bus with a non-trivial security policy + (such as the well-known system bus) may result in + access denial messages being logged for the reply. + </para> + <para> + Note that METHOD_CALL is the only message type currently + defined in this specification that can expect a reply, + so the presence or absence of this flag in the other + three message types that are currently + documented is meaningless: replies to those message + types should not be sent, whether this flag is present + or not. + </para> </entry> </row> <row> @@ -4431,7 +4447,9 @@ <literal>DESTINATION</literal> field is absent, it is considered to be a <firstterm>broadcast signal</firstterm>, and is sent to all applications with <firstterm>message matching rules</firstterm> that - match the message. Most signal messages are broadcasts. + match the message. Most signal messages are broadcasts, and + no other message types currently defined in this specification + may be broadcast. </para> <para> @@ -4471,7 +4489,7 @@ <para> Message bus implementations may impose a security policy which prevents certain messages from being sent or received. - When a message cannot be sent or received due to a security + When a method call message cannot be sent or received due to a security policy, the message bus should send an error reply, unless the original message had the <literal>NO_REPLY</literal> flag. </para> |