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<article id="index">
<articleinfo>
<title>D-Bus FAQ</title>
- <releaseinfo>Version 0.1</releaseinfo>
- <date>22 January 2005</date>
+ <releaseinfo>Version 0.3</releaseinfo>
+ <date>17 November 2006</date>
<authorgroup>
<author>
<firstname>Havoc</firstname>
</question>
<answer>
<para>
- This is probably best answered by reading the D-Bus <ulink url="dbus-tutorial.html">tutorial</ulink>. In
+ This is probably best answered by reading the D-Bus <ulink url="dbus-tutorial.html">tutorial</ulink> or
+ the introduction to the <ulink url="dbus-specification.html">specification</ulink>. In
short, it is a system consisting of 1) a wire protocol for exposing a
typical object-oriented language/framework to other applications; and
2) a bus daemon that allows applications to find and monitor one another.
+ Phrased differently, D-Bus is 1) an interprocess communication (IPC) system and 2) some higher-level
+ structure (lifecycle tracking, service activation, security policy) provided by two bus daemons,
+ one systemwide and one per-user-session.
</para>
</answer>
</qandaentry>
</question>
<answer>
<para>
- D-Bus has not yet reached 1.0. The <ulink url="README">README</ulink>
- file has a discussion of the API/ABI stability guarantees before and
- after 1.0. In short, there are no guarantees before 1.0, and stability
- of both protocol and reference library will be maintained after 1.0.
- As of January 2005 we don't expect major protocol or API changes prior
- to the 1.0 release, but anything is possible.
+ The low-level library "libdbus" and the protocol specification are considered
+ ABI stable. The <ulink url="README">README</ulink>
+ file has a discussion of the API/ABI stability guarantees.
+ Higher-level bindings (such as those for Qt, GLib, Python, Java, C#) each
+ have their own release schedules and degree of maturity, not linked to
+ the low-level library and bus daemon release. Check the project page for
+ the binding you're considering to understand that project's policies.
</para>
</answer>
</qandaentry>
are normally launched according to the bus name they will
have.
</para>
+ <para>
+ People often misuse the word "service" for any
+ bus name, but this tends to be ambiguous and confusing so is discouraged.
+ In the D-Bus docs we try to use "service" only when talking about
+ programs the bus knows how to launch, i.e. a service always has a
+ .service file.
+ </para>
</answer>
</qandaentry>
</question>
<answer>
<para>
+ Keep in mind, it is not only an IPC system; it also includes
+ lifecycle tracking, service activation, security policy, and other
+ higher-level structure and assumptions.
+ </para>
+ <para>
The best place to start is to read the D-Bus <ulink url="dbus-tutorial.html">tutorial</ulink>, so
you have a concrete idea what D-Bus actually is. If you
understand other protocols on a wire format level, you
for some specific use cases. Thus, it probably isn't tuned
for what you want to do, unless you are doing the things
D-Bus was designed for. Don't make the mistake of thinking
- that any system labeled "IPC" is the same thing.
+ that any system involving "IPC" is the same thing.
</para>
<para>
The D-Bus authors would not recommend using D-Bus
If you're writing a desktop application for UNIX,
then D-Bus is of course our recommendation for
talking to other parts of the desktop session.
- (With the caveat that you should use a stable release
- of D-Bus; until we reach 1.0, there isn't a stable release.)
+ </para>
+ <para>
+ D-Bus is also designed for communications between system daemons and
+ communications between the desktop and system daemons.
</para>
<para>
If you're doing something complicated such as clustering,
distributed swarms, peer-to-peer, or whatever then
the authors of this FAQ don't have expertise in these
areas and you should ask someone else or try a search engine.
+ D-Bus is most likely a poor choice but could be appropriate
+ for some things.
</para>
<para>
Note: the D-Bus mailing list is probably not the place to
projects / platform / upstream / dbus.git / blobdiff