Re: [GIT PULL] kdbus for 4.1-rc1

Andy Lutomirski
2015-04-29T19:42:27Z

On Wed, Apr 29, 2015 at 12:30 PM, Austin S Hemmelgarn
<ahferroin7@gmail.com> wrote:
> 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.
>

Then implement it the right way? The client sends some kind of
sequence number with its request.

--Andy