Doubts about comms with running bevy simulation

[karnotxo]

I'm still starting with rust and just discovered about ECS's
I'm trying to build kinda physics simulation and decided to use bevy_ecs... not a game nor need to display graphics, so I think it's ok... I'm encapsulating sim stuff in a lib and need this to generate soem udp messages as output. Also, I'm planning to have two options for launchinh. First from command line, with a few parameters and just launching simulation... or also from a minimal ui, that should display some statistics from the simulation in real time. I think I have idea about building any of these modules alone but not sure about how to build communication with muy running simulation, so:

1. any thoughts about how to implement a system that sends this UDP messaging (also, data sent by messaging includes a lot more info than what is strictly needed for running our simulation, so this info musdt be taken from somewhere else... perhaps a database?)
2. how should I do for querying from this minimal UI to my running simulation so I can show some statistics in my widgets? (I guess simulation should run in a different thread from UI)
   Thanks a lot in advance!

[lukors]

Answers to questions:

1. When you have the data you want to send you generate messages and send it. I'm probably misunderstanding the question. I don't understand what you've written in the parenthesis, so that might be where my problem lies.
2. The way I've solved this in my application is that the library runs in a thread, and it writes information to a place accessible from the outside, which I can then read from Bevy without blocking. I'm using RwLocks for this.

[karnotxo]

Thanks Lukors. I edited my question so what I wrote into parentheses has soem sense now... Sorry for that :/
I'm afraid writing to a file for data exchange would be not fast enough... Perhaps some king of message qeue or synchronized memory based struct could be an option?

[lukors]

Thank you for clarifying question 1! :)

I think the UDP stuff is probably too advanced for me as I still don't understand it. So I don't think I can help there.

---

I don't mean writing it to a file, I mean writing it to a place in memory that can be reached from outside the thread. RwLock lets you do stuff like have a struct that can be reached from two different threads.

So you could have somehting like Arc<RwLock<MyStruct>>, then you just clone the Arc and give that to the thread when you create it, and that enables you to lock the RwLock to read or write to it from both threads whenever you want. :)