Re: [chuck-users] TCP protocol

LOL! Jordan, that's amazing! You would. I can't wait to play with that! With OSC over TCP, you could really do some longer distance communications with chuck. And it seems it would be pretty responsive, based on Mark's post. I guess just watch those state change messages on the receiving end unless you have two-way comms. Think like a web developer, hehe. I want to see some callbacks and generators in chuck now. I think Michael Heuer has that stuff in LiCK? M On Tue, Dec 4, 2018 at 12:08 Jordan Orelli wrote:

ok, I had a little time to look at this, so I wrote you a simple proxy server in Go: https://github.com/jordanorelli/tuntun

there's a binary release here if you want to just have a downloadable binary to check it out:https://github.com/jordanorelli/tuntun/releases

and there's an example of how you'd use it from Chuck here: https://github.com/jordanorelli/tuntun/blob/master/ex/ex.ck

this is a pretty straightforward proxying server to write. If you're not familiar with writing network servers, this is a good entry-level project for learning about it.

Chuck's subprocess facilities are, ... well, pretty weird. It doesn't seem like you get the pid of the spawned process; there's no way to signal it, so there's no way to kill it from Chuck. This example leaves you with a zombie process.

I'm very confused as to how it operates internally, because it blocks the entire Chuck VM ... *unless *you stick an ampersand at the end of your command, which seems to put the job in the background. It ... it kinda looks like it's calling exec to exec a bash shell in the *current *process? I'm ... a bit baffled by the behavior, to be honest, but I found a way to work it out.

Running it this way means that Chuck launches the proxying server for you and can tell the proxying server the ports to use. You could also run the server yourself outside of Chuck to not have to deal with the weirdness of Chuck's subprocessing facilities.

On Tue, Dec 4, 2018 at 10:59 AM Mark Cerqueira wrote:

...

Roger Dannenberg did some real-time music work and compared UDP and TCP. His findings may surprise you! See 4.2 UDP vs. TCP here: https://www.cs.cmu.edu/~rbd/papers/icmc01aura.pdf tl;dr - he ended up going with TCP with some tweaks to make it more timely.

Cheers!

mc

On Sun, Dec 2, 2018 at 12:47 PM Jordan Orelli wrote:

...

I'm like ... 80% sure that there's no TCP-handling facilities built in, but I may be wrong here. If there is, I surely don't know about it.

Can you tell us a little more about your use case?

The design goals of TCP and ChucK are very different with respect to *time*. ChucK is designed around guarantees about time and timeliness. TCP is not designed around timeliness or latency in general: TCP is designed around guarantees about ordering (messages always appear in order) and delivery (messages are guaranteed to be delivered). Since every byte sent over a TCP socket has to be eventually acknowledged, and all bytes have to be processed in order, a stall in the network (a normal occurrence) could mean later messages being delayed, much like a traffic jam. It's not possible to have timing *guarantees *with TCP.

I'm not sure how to find it in the source code, but maybe someone else here knows: does calling Std.system create a new shell process for each invocation? That would be a fairly inefficient way to go about things. Also since you're piping to another process, that's a new netcat process for each invocation (so it's either one or two processes per invocation), and a new TCP socket for every invocation. TCP is *especially slow *at *the very beginning of communication.*

If I were in your shoes, I would probably write a separate program that acts as a server and serves an OSC-based protocol. This server would take your messages as OSC and translate them and then forward them to the intended recipient over just one TCP connection and continue to use that one connection the whole time. It may or may not respond to your ChucK program over OSC, depending on whether you want the ChucK program to get responses to its requests (probably not?).

On Sat, Dec 1, 2018 at 1:25 PM mario buoninfante < mario.buoninfante@gmail.com> wrote:

...

Hi,

It seems like accessing the shell and use "netcat" (on Unix) is a possible solution. Quite an *exotic* workaround but better than nothing I'd say.

Something like that seems to work:

*// run ChucK with "--caution-to-the-wind"*

*"echo -ne '" => string prefix;* *"' | netcat 127.0.0.1 3333 " => string suffix; // netcat <target ip> <target port>*

*while(true)* *{* * Math.random2(0,127) => int r;* * prefix + Std.itoa(r) + suffix => string msg;* * Std.system(msg);*

* second => now;* *}*

Please, let me know if anyone has a better solution.

Cheers,

Mario On 01/12/2018 18:04, mario buoninfante wrote:

Hi,

I also tried opening a file in /dev/tcp/<target ip>/<target port>, but it didn't work. I'm on Ubuntu 16.04. Any idea?

Cheers,

Mario

On 30/11/2018 16:52, Mario Buoninfante wrote:

Hi,

Does anyone know if it's possible to use TCP instead of UDP in ChucK?

Cheers, Mario

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