chore: use LocalSet for daemon tasks, replace mutex/rwlock with refcell

lact-daemon/src/lib.rs

@@ -15,6 +15,7 @@ use std::str::FromStr;
 use tokio::{
     runtime,
     signal::unix::{signal, SignalKind},
+    task::LocalSet,
 };
 use tracing::{debug_span, info, Instrument, Level};
 
@@ -42,13 +43,17 @@ pub fn run() -> anyhow::Result<()> {
         let max_level = Level::from_str(&config.daemon.log_level).context("Invalid log level")?;
         tracing_subscriber::fmt().with_max_level(max_level).init();
 
-        let server = Server::new(config).await?;
-        let handler = server.handler.clone();
+        LocalSet::new()
+            .run_until(async move {
+                let server = Server::new(config).await?;
+                let handler = server.handler.clone();
 
-        tokio::spawn(listen_exit_signals(handler.clone()));
-        tokio::spawn(suspend::listen_events(handler));
-        server.run().await;
-        Ok(())
+                tokio::task::spawn_local(listen_exit_signals(handler.clone()));
+                tokio::task::spawn_local(suspend::listen_events(handler));
+                server.run().await;
+                Ok(())
+            })
+            .await
     })
 }
 
@@ -63,11 +68,15 @@ pub fn run_embedded(stream: StdUnixStream) -> anyhow::Result<()> {
         .build()
         .expect("Could not initialize tokio runtime");
     rt.block_on(async {
-        let config = Config::default();
-        let handler = Handler::new(config).await?;
-        let stream = stream.try_into()?;
+        LocalSet::new()
+            .run_until(async move {
+                let config = Config::default();
+                let handler = Handler::new(config).await?;
+                let stream = stream.try_into()?;
 
-        handle_stream(stream, handler).await
+                handle_stream(stream, handler).await
+            })
+            .await
     })
 }
 

lact-daemon/src/server/gpu_controller/mod.rs

@@ -20,8 +20,9 @@ use lact_schema::{
 use pciid_parser::Database;
 use std::{
     borrow::Cow,
+    cell::RefCell,
     path::{Path, PathBuf},
-    sync::{Arc, Mutex},
+    rc::Rc,
     time::Duration,
 };
 use tokio::{select, sync::Notify, task::JoinHandle, time::sleep};
@@ -33,14 +34,14 @@ use {
     std::{fs::File, os::fd::IntoRawFd},
 };
 
-type FanControlHandle = (Arc<Notify>, JoinHandle<()>);
+type FanControlHandle = (Rc<Notify>, JoinHandle<()>);
 
 pub struct GpuController {
     pub handle: GpuHandle,
     #[cfg(feature = "libdrm_amdgpu_sys")]
     pub drm_handle: Option<DrmHandle>,
     pub pci_info: Option<GpuPciInfo>,
-    pub fan_control_handle: Mutex<Option<FanControlHandle>>,
+    pub fan_control_handle: RefCell<Option<FanControlHandle>>,
 }
 
 impl GpuController {
@@ -111,7 +112,7 @@ impl GpuController {
             #[cfg(feature = "libdrm_amdgpu_sys")]
             drm_handle,
             pci_info,
-            fan_control_handle: Mutex::new(None),
+            fan_control_handle: RefCell::new(None),
         })
     }
 
@@ -232,7 +233,7 @@ impl GpuController {
     pub fn get_stats(&self, gpu_config: Option<&config::Gpu>) -> anyhow::Result<DeviceStats> {
         let fan_control_enabled = self
             .fan_control_handle
-            .lock()
+            .try_borrow()
             .map_err(|err| anyhow!("Could not lock fan control mutex: {err}"))?
             .is_some();
 
@@ -311,13 +312,13 @@ impl GpuController {
 
         let mut notify_guard = self
             .fan_control_handle
-            .lock()
+            .try_borrow_mut()
             .map_err(|err| anyhow!("Lock error: {err}"))?;
 
-        let notify = Arc::new(Notify::new());
+        let notify = Rc::new(Notify::new());
         let task_notify = notify.clone();
 
-        let handle = tokio::spawn(async move {
+        let handle = tokio::task::spawn_local(async move {
             loop {
                 select! {
                     _ = sleep(interval) => (),
@@ -352,7 +353,7 @@ impl GpuController {
     async fn stop_fan_control(&self, reset_mode: bool) -> anyhow::Result<()> {
         let maybe_notify = self
             .fan_control_handle
-            .lock()
+            .try_borrow_mut()
             .map_err(|err| anyhow!("Lock error: {err}"))?
             .take();
         if let Some((notify, handle)) = maybe_notify {

lact-daemon/src/server/handler.rs

@@ -6,13 +6,7 @@ use lact_schema::{
     request::{ConfirmCommand, SetClocksCommand},
     ClocksInfo, DeviceInfo, DeviceListEntry, DeviceStats, FanCurveMap,
 };
-use std::{
-    collections::BTreeMap,
-    env,
-    path::PathBuf,
-    sync::{Arc, Mutex, RwLock},
-    time::Duration,
-};
+use std::{cell::RefCell, collections::BTreeMap, env, path::PathBuf, rc::Rc, time::Duration};
 use tokio::{sync::oneshot, time::sleep};
 use tracing::{debug, error, info, trace, warn};
 
@@ -21,9 +15,9 @@ const CONTROLLERS_LOAD_RETRY_INTERVAL: u64 = 1;
 
 #[derive(Clone)]
 pub struct Handler {
-    pub config: Arc<RwLock<Config>>,
-    pub gpu_controllers: Arc<BTreeMap<String, GpuController>>,
-    confirm_config_tx: Arc<Mutex<Option<oneshot::Sender<ConfirmCommand>>>>,
+    pub config: Rc<RefCell<Config>>,
+    pub gpu_controllers: Rc<BTreeMap<String, GpuController>>,
+    confirm_config_tx: Rc<RefCell<Option<oneshot::Sender<ConfirmCommand>>>>,
 }
 
 impl<'a> Handler {
@@ -45,9 +39,9 @@ impl<'a> Handler {
         info!("initialized {} GPUs", controllers.len());
 
         let handler = Self {
-            gpu_controllers: Arc::new(controllers),
-            config: Arc::new(RwLock::new(config)),
-            confirm_config_tx: Arc::new(Mutex::new(None)),
+            gpu_controllers: Rc::new(controllers),
+            config: Rc::new(RefCell::new(config)),
+            confirm_config_tx: Rc::new(RefCell::new(None)),
         };
         handler.load_config().await;
 
@@ -55,7 +49,7 @@ impl<'a> Handler {
     }
 
     pub async fn load_config(&self) {
-        let config = self.config.read().expect("Faied to lock config").clone(); // Clone to avoid locking the RwLock on an await point
+        let config = self.config.borrow().clone(); // Clone to avoid locking the RwLock on an await point
 
         for (id, gpu_config) in &config.gpus {
             if let Some(controller) = self.gpu_controllers.get(id) {
@@ -75,7 +69,7 @@ impl<'a> Handler {
     ) -> anyhow::Result<u64> {
         if self
             .confirm_config_tx
-            .try_lock()
+            .try_borrow_mut()
             .map_err(|err| anyhow!("{err}"))?
             .is_some()
         {
@@ -85,7 +79,7 @@ impl<'a> Handler {
         }
 
         let (gpu_config, apply_timer) = {
-            let config = self.config.read().map_err(|err| anyhow!("{err}"))?;
+            let config = self.config.try_borrow().map_err(|err| anyhow!("{err}"))?;
             let apply_timer = config.apply_settings_timer;
             let gpu_config = config.gpus.get(&id).cloned().unwrap_or_default();
             (gpu_config, apply_timer)
@@ -123,12 +117,12 @@ impl<'a> Handler {
         let (tx, rx) = oneshot::channel();
         *self
             .confirm_config_tx
-            .try_lock()
+            .try_borrow_mut()
             .map_err(|err| anyhow!("{err}"))? = Some(tx);
 
         let handler = self.clone();
 
-        tokio::task::spawn(async move {
+        tokio::task::spawn_local(async move {
             let controller = handler
                 .controller_by_id(&id)
                 .expect("GPU controller disappeared");
@@ -146,7 +140,7 @@ impl<'a> Handler {
                         Ok(ConfirmCommand::Confirm) => {
                             info!("saving updated config");
 
-                            let mut config_guard = handler.config.write().unwrap();
+                            let mut config_guard = handler.config.borrow_mut();
                             config_guard.gpus.insert(id, new_config);
 
                             if let Err(err) = config_guard.save() {
@@ -162,7 +156,7 @@ impl<'a> Handler {
                 }
             }
 
-            match handler.confirm_config_tx.try_lock() {
+            match handler.confirm_config_tx.try_borrow_mut() {
                 Ok(mut guard) => *guard = None,
                 Err(err) => error!("{err}"),
             }
@@ -199,7 +193,7 @@ impl<'a> Handler {
     pub fn get_gpu_stats(&'a self, id: &str) -> anyhow::Result<DeviceStats> {
         let config = self
             .config
-            .read()
+            .try_borrow()
             .map_err(|err| anyhow!("Could not read config: {err:?}"))?;
         let gpu_config = config.gpus.get(id);
         self.controller_by_id(id)?.get_stats(gpu_config)
@@ -220,7 +214,10 @@ impl<'a> Handler {
                 let curve = FanCurve(raw_curve);
                 curve.validate()?;
 
-                let mut config_guard = self.config.write().map_err(|err| anyhow!("{err}"))?;
+                let mut config_guard = self
+                    .config
+                    .try_borrow_mut()
+                    .map_err(|err| anyhow!("{err}"))?;
                 let gpu_config = config_guard.gpus.entry(id.to_owned()).or_default();
 
                 if let Some(mut existing_settings) = gpu_config.fan_control_settings.clone() {
@@ -312,7 +309,7 @@ impl<'a> Handler {
     pub fn confirm_pending_config(&self, command: ConfirmCommand) -> anyhow::Result<()> {
         if let Some(tx) = self
             .confirm_config_tx
-            .try_lock()
+            .try_borrow_mut()
             .map_err(|err| anyhow!("{err}"))?
             .take()
         {
@@ -326,7 +323,7 @@ impl<'a> Handler {
     pub async fn cleanup(self) {
         let disable_clocks_cleanup = self
             .config
-            .try_read()
+            .try_borrow()
             .map(|config| config.daemon.disable_clocks_cleanup)
             .unwrap_or(false);
 

lact-daemon/src/server/mod.rs

@@ -34,7 +34,7 @@ impl Server {
             match self.listener.accept().await {
                 Ok((stream, _)) => {
                     let handler = self.handler.clone();
-                    tokio::spawn(async move {
+                    tokio::task::spawn_local(async move {
                         if let Err(error) = handle_stream(stream, handler).await {
                             error!("{error}");
                         }