refactor: use a RwLock for event listeners

Cargo.lock

@@ -1184,6 +1184,7 @@ dependencies = [
  "bevy_log",
  "clap",
  "futures",
+ "futures-locks",
  "http-body-util",
  "hyper",
  "hyper-util",
@@ -1317,6 +1318,17 @@ dependencies = [
  "pin-project-lite",
 ]
 
+[[package]]
+name = "futures-locks"
+version = "0.7.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "45ec6fe3675af967e67c5536c0b9d44e34e6c52f86bedc4ea49c5317b8e94d06"
+dependencies = [
+ "futures-channel",
+ "futures-task",
+ "tokio",
+]
+
 [[package]]
 name = "futures-macro"
 version = "0.3.31"

Cargo.toml

@@ -21,6 +21,7 @@ bevy_app = "0"
 bevy_log = "0"
 clap = { version = "4", features = ["derive"] }
 futures = "0"
+futures-locks = "0"
 http-body-util = "0"
 hyper = { version = "1", features = ["server"] }
 hyper-util = "0"

src/events.rs

@@ -123,7 +123,7 @@ pub async fn handle_event(client: Client, event: Event, state: State) -> anyhow:
 }
 
 async fn call_listeners<T: Clone + IntoLuaMulti>(state: &State, event_type: &str, data: T) {
-    if let Some(listeners) = state.event_listeners.lock().await.get(event_type) {
+    if let Some(listeners) = state.event_listeners.read().await.get(event_type) {
         for (_, listener) in listeners {
             if let Err(error) = listener.call_async::<()>(data.clone()).await {
                 error!("failed to call lua event listener for {event_type}: {error:?}");

src/lua/events.rs

@@ -1,16 +1,9 @@
 use crate::ListenerMap;
-use futures::{executor::block_on, lock::Mutex};
+use futures::executor::block_on;
 use mlua::{Function, Lua, Result, Table};
-use std::{
-    sync::Arc,
-    time::{SystemTime, UNIX_EPOCH},
-};
+use std::time::{SystemTime, UNIX_EPOCH};
 
-pub fn register_functions(
-    lua: &Lua,
-    globals: &Table,
-    event_listeners: Arc<Mutex<ListenerMap>>,
-) -> Result<()> {
+pub fn register_functions(lua: &Lua, globals: &Table, event_listeners: ListenerMap) -> Result<()> {
     let m = event_listeners.clone();
     globals.set(
         "add_listener",
@@ -18,7 +11,7 @@ pub fn register_functions(
             move |_, (event_type, callback, id): (String, Function, Option<String>)| {
                 let m = m.clone();
                 tokio::spawn(async move {
-                    m.lock().await.entry(event_type).or_default().push((
+                    m.write().await.entry(event_type).or_default().push((
                         id.unwrap_or(callback.info().name.unwrap_or(format!(
                                 "anonymous @ {}",
                                 SystemTime::now()
@@ -40,7 +33,7 @@ pub fn register_functions(
         lua.create_function(move |_, (event_type, target_id): (String, String)| {
             let m = m.clone();
             tokio::spawn(async move {
-                let mut m = m.lock().await;
+                let mut m = m.write().await;
                 let empty = if let Some(listeners) = m.get_mut(&event_type) {
                     listeners.retain(|(id, _)| target_id != *id);
                     listeners.is_empty()
@@ -58,7 +51,7 @@ pub fn register_functions(
     globals.set(
         "get_listeners",
         lua.create_function(move |lua, (): ()| {
-            let m = block_on(event_listeners.lock());
+            let m = block_on(event_listeners.read());
 
             let listeners = lua.create_table()?;
             for (event_type, callbacks) in m.iter() {

src/lua/mod.rs

@@ -9,9 +9,8 @@ pub mod system;
 pub mod vec3;
 
 use crate::ListenerMap;
-use futures::lock::Mutex;
 use mlua::{Lua, Table};
-use std::{io, sync::Arc, time::Duration};
+use std::{io, time::Duration};
 
 #[derive(Debug)]
 #[allow(dead_code)]
@@ -27,7 +26,7 @@ pub enum Error {
 pub fn register_functions(
     lua: &Lua,
     globals: &Table,
-    event_listeners: Arc<Mutex<ListenerMap>>,
+    event_listeners: ListenerMap,
 ) -> mlua::Result<()> {
     globals.set(
         "sleep",

src/main.rs

@@ -17,6 +17,7 @@ use bevy_log::{
 use clap::Parser;
 use commands::{CommandSource, register};
 use futures::lock::Mutex;
+use futures_locks::RwLock;
 use mlua::{Function, Lua};
 use std::{
     collections::HashMap,
@@ -29,12 +30,12 @@ use std::{
 
 const DEFAULT_SCRIPT_PATH: &str = "errornowatcher.lua";
 
-type ListenerMap = HashMap<String, Vec<(String, Function)>>;
+type ListenerMap = Arc<RwLock<HashMap<String, Vec<(String, Function)>>>>;
 
 #[derive(Default, Clone, Component)]
 pub struct State {
     lua: Lua,
-    event_listeners: Arc<Mutex<ListenerMap>>,
+    event_listeners: ListenerMap,
     commands: Arc<CommandDispatcher<Mutex<CommandSource>>>,
     http_address: Option<SocketAddr>,
 }
@@ -44,7 +45,7 @@ async fn main() -> anyhow::Result<()> {
     let args = arguments::Arguments::parse();
 
     let script_path = args.script.unwrap_or(PathBuf::from(DEFAULT_SCRIPT_PATH));
-    let event_listeners = Arc::new(Mutex::new(HashMap::new()));
+    let event_listeners = Arc::new(RwLock::new(HashMap::new()));
 
     let lua = Lua::new();
     let globals = lua.globals();