Implement functional but blocking task lib in rust

src/lib/globals/console.rs

@@ -5,7 +5,7 @@ use crate::utils::{
     table_builder::ReadonlyTableBuilder,
 };
 
-pub async fn create(lua: Lua) -> Result<Lua> {
+pub async fn create(lua: &Lua) -> Result<()> {
     let print = |args: &MultiValue, throw: bool| -> Result<()> {
         let s = pretty_format_multi_value(args)?;
         if throw {
@@ -18,7 +18,7 @@ pub async fn create(lua: Lua) -> Result<Lua> {
     };
     lua.globals().raw_set(
         "console",
-        ReadonlyTableBuilder::new(&lua)?
+        ReadonlyTableBuilder::new(lua)?
             .with_function("resetColor", |_, _: ()| print_color("reset"))?
             .with_function("setColor", |_, color: String| print_color(color))?
             .with_function("resetStyle", |_, _: ()| print_style("reset"))?
@@ -40,6 +40,5 @@ pub async fn create(lua: Lua) -> Result<Lua> {
                 print(&args, true)
             })?
             .build()?,
-    )?;
-    Ok(lua)
+    )
 }

src/lib/globals/fs.rs

@@ -5,10 +5,10 @@ use tokio::fs;
 
 use crate::utils::table_builder::ReadonlyTableBuilder;
 
-pub async fn create(lua: Lua) -> Result<Lua> {
+pub async fn create(lua: &Lua) -> Result<()> {
     lua.globals().raw_set(
         "fs",
-        ReadonlyTableBuilder::new(&lua)?
+        ReadonlyTableBuilder::new(lua)?
             .with_async_function("readFile", fs_read_file)?
             .with_async_function("readDir", fs_read_dir)?
             .with_async_function("writeFile", fs_write_file)?
@@ -18,8 +18,7 @@ pub async fn create(lua: Lua) -> Result<Lua> {
             .with_async_function("isFile", fs_is_file)?
             .with_async_function("isDir", fs_is_dir)?
             .build()?,
-    )?;
-    Ok(lua)
+    )
 }
 
 async fn fs_read_file(_: &Lua, path: String) -> Result<String> {

src/lib/globals/net.rs

@@ -8,16 +8,15 @@ use reqwest::{
 
 use crate::utils::{net::get_request_user_agent_header, table_builder::ReadonlyTableBuilder};
 
-pub async fn create(lua: Lua) -> Result<Lua> {
+pub async fn create(lua: &Lua) -> Result<()> {
     lua.globals().raw_set(
         "net",
-        ReadonlyTableBuilder::new(&lua)?
+        ReadonlyTableBuilder::new(lua)?
             .with_function("jsonEncode", net_json_encode)?
             .with_function("jsonDecode", net_json_decode)?
             .with_async_function("request", net_request)?
             .build()?,
-    )?;
-    Ok(lua)
+    )
 }
 
 fn net_json_encode(_: &Lua, (val, pretty): (Value, Option<bool>)) -> Result<String> {

src/lib/globals/process.rs

@@ -9,7 +9,7 @@ use tokio::process::Command;
 
 use crate::utils::table_builder::ReadonlyTableBuilder;
 
-pub async fn create(lua: Lua, args_vec: Vec<String>) -> Result<Lua> {
+pub async fn create(lua: &Lua, args_vec: Vec<String>) -> Result<()> {
     // Create readonly args array
     let inner_args = lua.create_table()?;
     for arg in &args_vec {
@@ -38,14 +38,13 @@ pub async fn create(lua: Lua, args_vec: Vec<String>) -> Result<Lua> {
     // Create the full process table
     lua.globals().raw_set(
         "process",
-        ReadonlyTableBuilder::new(&lua)?
+        ReadonlyTableBuilder::new(lua)?
             .with_table("args", inner_args)?
             .with_table("env", inner_env)?
             .with_function("exit", process_exit)?
             .with_async_function("spawn", process_spawn)?
             .build()?,
-    )?;
-    Ok(lua)
+    )
 }
 
 fn process_env_get<'lua>(lua: &'lua Lua, (_, key): (Value<'lua>, String)) -> Result<Value<'lua>> {

src/lib/globals/task.rs

@@ -1,27 +1,80 @@
 use std::time::Duration;
 
-use mlua::{Lua, Result};
-use tokio::time;
+use mlua::{Error, Function, Lua, Result, Table, Thread, Value, Variadic};
+use tokio::time::{self, Instant};
 
 use crate::utils::table_builder::ReadonlyTableBuilder;
 
-const DEFAULT_SLEEP_DURATION: f32 = 1.0 / 60.0;
-
-pub async fn create(lua: Lua) -> Result<Lua> {
+pub async fn create(lua: &Lua) -> Result<()> {
     lua.globals().raw_set(
         "task",
-        ReadonlyTableBuilder::new(&lua)?
+        ReadonlyTableBuilder::new(lua)?
+            .with_async_function("cancel", task_cancel)?
+            .with_async_function("defer", task_defer)?
+            .with_async_function("delay", task_delay)?
+            .with_async_function("spawn", task_spawn)?
             .with_async_function("wait", task_wait)?
             .build()?,
-    )?;
-    Ok(lua)
+    )
 }
 
-// FIXME: It does seem possible to properly make an async wait
-// function with mlua right now, something breaks when using
-// async wait functions inside of coroutines
-async fn task_wait(_: &Lua, duration: Option<f32>) -> Result<f32> {
-    let secs = duration.unwrap_or(DEFAULT_SLEEP_DURATION);
-    time::sleep(Duration::from_secs_f32(secs)).await;
-    Ok(secs)
+fn get_thread_from_arg<'a>(lua: &'a Lua, thread_or_function_arg: Value<'a>) -> Result<Thread<'a>> {
+    Ok(match thread_or_function_arg {
+        Value::Thread(thread) => thread,
+        Value::Function(func) => lua.create_thread(func)?,
+        val => {
+            return Err(Error::RuntimeError(format!(
+                "Expected type thread or function, got {}",
+                val.type_name()
+            )))
+        }
+    })
+}
+
+async fn task_cancel(lua: &Lua, thread: Thread<'_>) -> Result<()> {
+    let coroutine: Table = lua.globals().raw_get("coroutine")?;
+    let close: Function = coroutine.raw_get("close")?;
+    close.call_async(thread).await?;
+    Ok(())
+}
+
+async fn task_defer<'a>(lua: &Lua, (tof, args): (Value<'a>, Variadic<Value<'a>>)) -> Result<()> {
+    task_wait(lua, None).await?;
+    get_thread_from_arg(lua, tof)?
+        .into_async::<_, Variadic<Value<'_>>>(args)
+        .await?;
+    Ok(())
+}
+
+async fn task_delay<'a>(
+    lua: &Lua,
+    (delay, tof, args): (Option<f32>, Value<'a>, Variadic<Value<'a>>),
+) -> Result<()> {
+    task_wait(lua, delay).await?;
+    get_thread_from_arg(lua, tof)?
+        .into_async::<_, Variadic<Value<'_>>>(args)
+        .await?;
+    Ok(())
+}
+
+async fn task_spawn<'a>(lua: &Lua, (tof, args): (Value<'a>, Variadic<Value<'a>>)) -> Result<()> {
+    get_thread_from_arg(lua, tof)?
+        .into_async::<_, Variadic<Value<'_>>>(args)
+        .await?;
+    Ok(())
+}
+
+// FIXME: It doesn't seem possible to properly make an async wait
+// function with mlua right now, something breaks when using
+// the async wait function inside of a coroutine
+async fn task_wait(_: &Lua, duration: Option<f32>) -> Result<f32> {
+    let start = Instant::now();
+    time::sleep(
+        duration
+            .map(Duration::from_secs_f32)
+            .unwrap_or(Duration::ZERO),
+    )
+    .await;
+    let end = Instant::now();
+    Ok((end - start).as_secs_f32())
 }

src/lib/lib.rs

@@ -2,6 +2,7 @@ use std::collections::HashSet;
 
 use anyhow::{bail, Result};
 use mlua::Lua;
+use tokio::task;
 
 pub mod globals;
 pub mod utils;
@@ -61,17 +62,27 @@ impl Lune {
     }
 
     pub async fn run(&self, name: &str, chunk: &str) -> Result<()> {
-        let mut lua = Lua::new();
-        for global in &self.globals {
-            lua = match &global {
-                LuneGlobal::Console => create_console(lua).await?,
-                LuneGlobal::Fs => create_fs(lua).await?,
-                LuneGlobal::Net => create_net(lua).await?,
-                LuneGlobal::Process => create_process(lua, self.args.clone()).await?,
-                LuneGlobal::Task => create_task(lua).await?,
+        let run_name = name.to_owned();
+        let run_chunk = chunk.to_owned();
+        let run_globals = self.globals.to_owned();
+        let run_args = self.args.to_owned();
+        // Spawn a thread-local task so that we can then spawn
+        // more tasks in our globals without the Send requirement
+        let local = task::LocalSet::new();
+        local
+            .run_until(async move {
+                task::spawn_local(async move {
+                    let lua = Lua::new();
+                    for global in &run_globals {
+                        match &global {
+                            LuneGlobal::Console => create_console(&lua).await?,
+                            LuneGlobal::Fs => create_fs(&lua).await?,
+                            LuneGlobal::Net => create_net(&lua).await?,
+                            LuneGlobal::Process => create_process(&lua, run_args.clone()).await?,
+                            LuneGlobal::Task => create_task(&lua).await?,
                         }
                     }
-        let result = lua.load(chunk).set_name(name)?.exec_async().await;
+                    let result = lua.load(&run_chunk).set_name(&run_name)?.exec_async().await;
                     match result {
                         Ok(_) => Ok(()),
                         Err(e) => bail!(
@@ -80,6 +91,11 @@ impl Lune {
                             pretty_format_luau_error(&e)
                         ),
                     }
+                })
+                .await
+                .unwrap()
+            })
+            .await
     }
 }
 

src/lib/luau/task.luau

@@ -1,112 +0,0 @@
-local MINIMUM_DELAY_TIME = 1 / 100
-
-type ThreadOrFunction<A..., R...> = thread | (A...) -> R...
-type AnyThreadOrFunction = ThreadOrFunction<...any, ...any>
-
-type WaitingThreadKind = "Normal" | "Deferred" | "Delayed"
-type WaitingThread = {
-	idx: number,
-	kind: WaitingThreadKind,
-	thread: thread,
-	args: { [number]: any, n: number },
-}
-
-local waitingThreadCounter = 0
-local waitingThreads: { WaitingThread } = {}
-
-local function scheduleWaitingThreads()
-	-- Grab currently waiting threads and clear the queue but keep capacity
-	local threadsToResume: { WaitingThread } = table.clone(waitingThreads)
-	table.clear(waitingThreads)
-	table.sort(threadsToResume, function(t0, t1)
-		local k0: WaitingThreadKind = t0.kind
-		local k1: WaitingThreadKind = t1.kind
-		if k0 == k1 then
-			return t0.idx < t1.idx
-		end
-		if k0 == "Normal" then
-			return true
-		elseif k1 == "Normal" then
-			return false
-		elseif k0 == "Deferred" then
-			return true
-		else
-			return false
-		end
-	end)
-	-- Resume threads in order, giving args & waiting if necessary
-	for _, waitingThread in threadsToResume do
-		coroutine.resume(
-			waitingThread.thread,
-			table.unpack(waitingThread.args, 1, waitingThread.args.n)
-		)
-	end
-end
-
-local function insertWaitingThread(kind: WaitingThreadKind, tof: AnyThreadOrFunction, ...: any)
-	if typeof(tof) ~= "thread" and typeof(tof) ~= "function" then
-		if tof == nil then
-			error("Expected thread or function, got nil", 3)
-		end
-		error(
-			string.format("Expected thread or function, got %s %s", typeof(tof), tostring(tof)),
-			3
-		)
-	end
-	local thread = if type(tof) == "function" then coroutine.create(tof) else tof
-	waitingThreadCounter += 1
-	local waitingThread: WaitingThread = {
-		idx = waitingThreadCounter,
-		kind = kind,
-		thread = thread,
-		args = table.pack(...),
-	}
-	table.insert(waitingThreads, waitingThread)
-	return waitingThread
-end
-
-local function cancel(thread: unknown)
-	if typeof(thread) ~= "thread" then
-		if thread == nil then
-			error("Expected thread, got nil", 2)
-		end
-		error(string.format("Expected thread, got %s %s", typeof(thread), tostring(thread)), 2)
-	else
-		coroutine.close(thread)
-	end
-end
-
-local function defer(tof: AnyThreadOrFunction, ...: any): thread
-	local waiting = insertWaitingThread("Deferred", tof, ...)
-	local original = waiting.thread
-	waiting.thread = coroutine.create(function(...)
-		task.wait(1 / 1_000_000)
-		coroutine.resume(original, ...)
-	end)
-	scheduleWaitingThreads()
-	return waiting.thread
-end
-
-local function delay(delay: number?, tof: AnyThreadOrFunction, ...: any): thread
-	local waiting = insertWaitingThread("Delayed", tof, ...)
-	local original = waiting.thread
-	waiting.thread = coroutine.create(function(...)
-		task.wait(math.max(MINIMUM_DELAY_TIME, delay or 0))
-		coroutine.resume(original, ...)
-	end)
-	scheduleWaitingThreads()
-	return waiting.thread
-end
-
-local function spawn(tof: AnyThreadOrFunction, ...: any): thread
-	local waiting = insertWaitingThread("Normal", tof, ...)
-	scheduleWaitingThreads()
-	return waiting.thread
-end
-
-return {
-	cancel = cancel,
-	defer = defer,
-	delay = delay,
-	spawn = spawn,
-}