mlua-luau-scheduler
An async scheduler for Luau, using [`mlua`][mlua] and built on top of [`async-executor`][async-executor].
This crate is runtime-agnostic and is compatible with any async runtime, including [Tokio][tokio], [smol][smol], [async-std][async-std], and others.
However, since many dependencies are shared with [smol][smol], depending on it over other runtimes may be preferred.
[async-executor]: https://crates.io/crates/async-executor
[async-std]: https://async.rs
[mlua]: https://crates.io/crates/mlua
[smol]: https://github.com/smol-rs/smol
[tokio]: https://tokio.rs
## Example Usage
### 1. Import dependencies
```rs
use std::time::{Duration, Instant};
use std::io::ErrorKind;
use async_io::{block_on, Timer};
use async_fs::read_to_string;
use mlua::prelude::*;
use mlua_luau_scheduler::*;
```
### 2. Set up Lua environment
```rs
let lua = Lua::new();
lua.globals().set(
"sleep",
lua.create_async_function(|_, duration: f64| async move {
let before = Instant::now();
let after = Timer::after(Duration::from_secs_f64(duration)).await;
Ok((after - before).as_secs_f64())
})?,
)?;
lua.globals().set(
"readFile",
lua.create_async_function(|lua, path: String| async move {
// Spawn background task that does not take up resources on the lua thread
// Normally, futures in mlua can not be shared across threads, but this can
let task = lua.spawn(async move {
match read_to_string(path).await {
Ok(s) => Ok(Some(s)),
Err(e) if e.kind() == ErrorKind::NotFound => Ok(None),
Err(e) => Err(e),
}
});
task.await.into_lua_err()
})?,
)?;
```
### 3. Set up scheduler, run threads
```rs
let sched = Scheduler::new(&lua)?;
// We can create multiple lua threads ...
let sleepThread = lua.load("sleep(0.1)");
let fileThread = lua.load("readFile(\"Cargo.toml\")");
// ... spawn them both onto the scheduler ...
sched.push_thread_front(sleepThread, ());
sched.push_thread_front(fileThread, ());
// ... and run until they finish
block_on(sched.run());
```
