Spawning a thread and call a function from lua

[ghosty2004]

Hi, I want to know if it's possible to export a spawn_thread function from a module which have a LuaFunction type argument and then call that function inside a rust thread?

I tried something like this:

use mlua::prelude::*;

fn spawn_thread(_: &Lua, func: LuaFunction) -> LuaResult<()> {
    println!("Spawning thread...");

    std::thread::spawn(move || {
        println!("Thread spawned");
        let _ = func.call(()).unwrap();
        println!("Thread finished");
    });

    Ok(())
}

#[mlua::lua_module]
fn my_module(lua: &Lua) -> LuaResult<LuaTable> {
    let exports = lua.create_table()?;
    exports.set("spawn_thread", lua.create_function(spawn_thread)?)?;
    Ok(exports)
}

but I get the following error from the compiler:

`*mut lua_State` cannot be shared between threads safely
within `mlua::lua::LuaInner`, the trait `Sync` is not implemented for `*mut lua_State`, which is required by `{closure@src/lib.rs:6:24: 6:31}: Send`
required for `Arc<mlua::lua::LuaInner>` to implement `Sync`
required for `&mlua::Lua` to implement `Send`

I'm using the following features: lua53, module, send

Any example about how can I achive multi thread like this will be appreciated.

[khvzak]

Lua (and mlua) is strictly !Sync, you cannot do this.
To achieve true parallelism you can spawn another Lua interpreter to execute function (passed as source code) then serialize results and pass back to main VM.

[cheesycod]

@khvzak can u send an example pls, I have this same issue on tokio