Re: [LAD] Realtime inter-thread communication

Thank you all for the responses!

On Mon, Feb 29, 2016 at 9:05 PM, Harry van Haaren <harryhaaren@email-addr-hidden> wrote:
> On Mon, Feb 29, 2016 at 7:52 PM, Spencer Jackson <ssjackson71@email-addr-hidden>
> wrote:
>> > The generic solution for cases like this is a lock-free ringbuffer.
>> I've also used the jack ringbuffer for this and it was easy enough.
>
> Simple tutorial on using JACK ringbuffer and C++ event class here:
> https://github.com/harryhaaren/realtimeAudioThreading

I've looked into JACK's ringbuffer implementation. It doesn't look too
complicated. Thank you all for suggesting it! But I'm a little bit
concerned about ISO standard compliance. According to the
multi-threading-aware update to the C11 and C++11 memory models, the
access to the ringbuffer's data (*buf) is technically a data race and
therefore invokes undefined behaviour. Only read_ptr/write_ptr are
somewhat protected (volatile). From what I understand, given the
C11/C++11 memory model, one is supposed to use "atomics" for all
read/write accesses in such situations (including *buf). But so far, I
havn't gathered much experience in this kind of lock-free programming.

>> >> But to be honest I've found this API to be a bit intimidating and I'm
>> >> not familiar with any LV2 host that would allow me to test such a
>> >> plugin. Any recommendations? Ardour?
>> >
>> > jalv, Carla, QTractor, Ardour..
>
> +1 for Jalv, very fast turnover time, and LV2 implementation
> by the lead LV2 developer: I concider it the reference implementation :)

Sounds good! I'll look into it...

>> > A LV2 simple synth example can be found at
>> > http://lv2plug.in/book/#_sampler
>>
>> I like jalv for debugging because its quite simple and quick to load.
>> I can run it with gdb and valgrind/callgrind without any trouble. I've
>> found it important to test in other hosts too though but only once its
>> working in jalv.
>
> +1 again
>
>> FWIW I hope you do make an LV2 plugin version as I rarely use
>> standalone synths these days.
>
> +1, and LV2 is supported by MOD (hardware platform that runs LV2):
> http://moddevices.com/ and https://vimeo.com/92739423

Yup. I see the benefit of having a synth as LV2 plugin instead of
standalone. It's more flexible and I would have to reinvent less
wheels. I just need to make friends with some of the LV2 hosts first.

>> If you have any questions about my code I've linked you are welcome to
>> ask. Also, LV2 has a ML and IRC channel and I'll be happy to offer any
>> advice or support there that I can too.
>
> Same!

Great!

Cheers!
SG
_______________________________________________
Linux-audio-dev mailing list
Linux-audio-dev@email-addr-hidden
http://lists.linuxaudio.org/listinfo/linux-audio-dev
Received on Tue Mar 1 20:15:02 2016