[pulseaudio-discuss] introduce the new feature of ring buffer log and ask for comments

[David Henningsson]

On 08/14/2012 08:19 AM, rong deng wrote:
> Hi David,
>
> Thanks for your comments, see my inlined comments below:
>
> 2012/8/14 David Henningsson <david.henningsson at canonical.com>:
>> On 08/13/2012 04:59 PM, rong deng wrote:
>>>
>>> Ask for comments
>>> ================
>>>
>>> We design this feature to try to be useful for users and developers. We'd
>>> like
>>> to hear from you how do you think. Please don't hesitate to give your
>>> valuable
>>> feedback!
>>
>>
>> Hmm, maybe we could add the output of "pactl log" to bugs reported against
>> the PulseAudio package in Ubuntu? That way maybe we don't have to ask for
>> PulseAudio logs all the time...so yes, then it could be helpful!
>
> Yes, this is one of our goals. In this way, developers only ask users
> to give the output of 'pactl log', users don't bother to kill
> PulseAudio and restart the daemon with somewhat verbose options.

Restarting PA is not necessary as "pacmd set-log-level" and "pacmd 
set-log-target" (?) exist.

>> 3) How long is the per-thread buffer by default (and is that in messages or
>> characters)? Would it make sense to have this limit configurable (in what
>> ways)?
>
> For each thread, it contains 200 log messages with each message at
> most 512 characters. As in the current implementation these numbers
> are hard coded. It's doable to make it configurable, but it would
> complicate the current code a lot. And it's best to configure it at
> run time.

Hmm. This means different threads will look back different lengths of 
time, e g, if thread A logs something once every second and thread B 
logs every 10 ms, that would mean pactl log would be something like:

198 msgs from thread A,
100 msgs from thread B,
1 msg from thread A,
100 msgs from thread B,
1 msg from thread A.

Perhaps it will be confusing that people will see the first 198 msgs 
from thread A without seeing the thread B messages in between?


-- 
David Henningsson, Canonical Ltd.
https://launchpad.net/~diwic