Re: [Linuxsampler-devel] Re: GSt3 is out - does not support multiple

[Christian S. <sch...@so...>]

Es geschah am Samstag, 4. September 2004 09:23 als St=E9phane LETZ schrieb:
> I'm working on a multi-processors version of Jack. Would it be a way to
> add  multi-processors  support to LS?
> For example if LS would be able to run multiple audio engines driven by
> multiple jack clients, then LS could be multi-processors !
>
> How difficult would it be to have a multiple audio engine model in the
> current version in order to test this idea?

Each engine on each sampler channel is independent already. The thread /=20
process context solely comes from the audio output device (=3Ddriver) the=20
respective engine is connected to. So you would only have to modify the JAC=
K=20
driver in LS a bit to be able to test it.

But I wonder if it wouldn't be better to implement a driver independent=20
solution. Because copying the audio data to the final driver output buffer=
=20
doesnt take much CPU time. Most of the CPU time is used for rendering the=20
data in each engine. So I would propose to implement a job dispatcher in th=
e=20
AudioOutputDevice base class which distributes jobs for calling threads. So=
=20
there would be a fix number of threads (which can be set by the user) which=
=20
just poll the AudioOutputDevice base class for scheduled render jobs and th=
e=20
driver thread itself asks the AudioOutputDevice class if all jobs are alrea=
dy=20
done, if not it will also take a free job and poll again if all jobs are=20
done. Finally when all jobs are done, the driver thread will just copy the=
=20
audio data to the driver output buffer.

Anyway, no matter what you do, please wait a bit til committing something l=
ike=20
that to CVS. I'm currently working to get things stable for the first=20
release.

CU
Christian