On 2015-04-29 14:54, Andy Lutomirski wrote:
> On Apr 29, 2015 5:48 AM, "Harald Hoyer" <harald@redhat.com> wrote:
>>
>>   * Being in the kernel closes a lot of races which can't be fixed with
>>     the current userspace solutions.  For example, with kdbus, there is a
>>     way a client can disconnect from a bus, but do so only if no further
>>     messages present in its queue, which is crucial for implementing
>>     race-free "exit-on-idle" services
>
> This can be implemented in userspace.
>
> Client to dbus daemon: may I exit now?
> Dbus daemon to client: yes (and no more messages) or no
>
Depending on how this is implemented, there would be a potential issue 
if a message arrived for the client after the daemon told it it could 
exit, but before it finished shutdown, in which case the message might 
get lost.