On Sat, Apr 11, 2015 at 1:25 PM, Johannes Lorenz <johannes89@mailueberfall.de> wrote:

> > Nonetheless, if I have 40 instances of zyn, I'd
> > like to (actually must) compute them concurrently. So how to do this with
> > one client?
>
> By using your own internal graph mechanism that has parallel capabilities.
> See, for excample, https://github.com/flowprogramming/dspatch

This one is based on pthread_cond_wait(), which is either implemented as a spinlock or not realtime safe (I guess the second). So how can this help?

it was just an example. ultimately, *some* synchronization primitive is required. the question is what is the least bad choice ....

> > The best way I can see is using an array of jack clients, and hoping
> > they'll process() at the same time. However, this sounds very tricky...
>
> There can be very good reasons for using JACK 1. If a user is doing that,
> you won't get any parallelization at all.

Does JACK 2 allow to use multiple jack clients that call process() at the same time? Or does it allow to enter process() with multiple threads? There seems to be no documentation/tutorial about JACK 2.

clients do not "call process". process() is called on their behalf, by the server, in a thread chosen by the server.

the relationship between threads and callbacks is an undocumented, implementation specific part of JACK, and differs between JACK1 and JACK2.