per-user dbus

Lennart Poettering mzqohf at
Fri Nov 13 15:04:08 PST 2009

On Fri, 13.11.09 10:27, Havoc Pennington (hp at wrote:

> If developers don't really think about multiple logins or NFS,
> per-session tends to mostly work as expected, while per-(user,machine)
> tends to get really hosed because a program has to be aware of
> multiple X servers and sessions to work properly if it's scoped
> per-(user,machine). Unfortunately, if there's something called
> DBUS_BUS_USER I think lots of devs will think "oh, I should use that"
> for something like config settings. But in all likelihood, they should
> not use it, because it will just fail - it would only "magically work"
> in the right way if it were per-user, not per-(user,machine).

I believe that a DBUS_BUS_USER_MACHINE would be a better place for a
config system than DBUS_BUS_SESSION, since -- as mentioned -- this
would make sure that at least multiple local sessions cannot step on
each others toes anymore.

DBUS_BUS_USER_MACHINE is nothing that would *fix* the network synchronization
issues that a configuration system on top of a shared FS has, but it
would ameliorate it at least for local sessions. So yes, I *want*
devs to make use of it, although it wouldn't fix the problem.

> per-(user,machine) is pretty much only useful for hardware-related
> stuff. Otherwise it needs to be per-user, not per-(user,machine).

I disagree.


Lennart Poettering                        Red Hat, Inc.
lennart [at] poettering [dot] net           GnuPG 0x1A015CC4

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