fix lsp config reload (#9415)

`syn_loader` was replaced rather than interior value being replace,
old value was still being referenced and not updated after `:config-refresh`.
By using `ArcSwap` like for `config`, each `.load()` call will return the most
updated value.

Co-authored-by: kyfan <kyfan@email>

13 files changed, 89 insertions, 41 deletions

diff --git a/Cargo.lock b/Cargo.lock
index 6131871d..6f38f003 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -1316,6 +1316,7 @@ name = "helix-lsp"
 version = "23.10.0"
 dependencies = [
  "anyhow",
+ "arc-swap",
  "futures-executor",
  "futures-util",
  "globset",
diff --git a/helix-core/src/syntax.rs b/helix-core/src/syntax.rs
index 5d45deaf..a9344448 100644
--- a/helix-core/src/syntax.rs
+++ b/helix-core/src/syntax.rs
@@ -1000,7 +1000,7 @@ thread_local! {
 pub struct Syntax {
     layers: HopSlotMap<LayerId, LanguageLayer>,
     root: LayerId,
-    loader: Arc<Loader>,
+    loader: Arc<ArcSwap<Loader>>,
 }
 
 fn byte_range_to_str(range: std::ops::Range<usize>, source: RopeSlice) -> Cow<str> {
@@ -1011,7 +1011,7 @@ impl Syntax {
     pub fn new(
         source: RopeSlice,
         config: Arc<HighlightConfiguration>,
-        loader: Arc<Loader>,
+        loader: Arc<ArcSwap<Loader>>,
     ) -> Option<Self> {
         let root_layer = LanguageLayer {
             tree: None,
@@ -1055,9 +1055,10 @@ impl Syntax {
         let mut queue = VecDeque::new();
         queue.push_back(self.root);
 
-        let scopes = self.loader.scopes.load();
+        let loader = self.loader.load();
+        let scopes = loader.scopes.load();
         let injection_callback = |language: &InjectionLanguageMarker| {
-            self.loader
+            loader
                 .language_configuration_for_injection_string(language)
                 .and_then(|language_config| language_config.highlight_config(&scopes))
         };
@@ -2663,7 +2664,12 @@ mod test {
         let mut cursor = QueryCursor::new();
 
         let config = HighlightConfiguration::new(language, "", "", "").unwrap();
-        let syntax = Syntax::new(source.slice(..), Arc::new(config), Arc::new(loader)).unwrap();
+        let syntax = Syntax::new(
+            source.slice(..),
+            Arc::new(config),
+            Arc::new(ArcSwap::from_pointee(loader)),
+        )
+        .unwrap();
 
         let root = syntax.tree().root_node();
         let mut test = |capture, range| {
@@ -2738,7 +2744,12 @@ mod test {
             fn main() {}
         ",
         );
-        let syntax = Syntax::new(source.slice(..), Arc::new(config), Arc::new(loader)).unwrap();
+        let syntax = Syntax::new(
+            source.slice(..),
+            Arc::new(config),
+            Arc::new(ArcSwap::from_pointee(loader)),
+        )
+        .unwrap();
         let tree = syntax.tree();
         let root = tree.root_node();
         assert_eq!(root.kind(), "source_file");
@@ -2829,7 +2840,12 @@ mod test {
         let language = get_language(language_name).unwrap();
 
         let config = HighlightConfiguration::new(language, "", "", "").unwrap();
-        let syntax = Syntax::new(source.slice(..), Arc::new(config), Arc::new(loader)).unwrap();
+        let syntax = Syntax::new(
+            source.slice(..),
+            Arc::new(config),
+            Arc::new(ArcSwap::from_pointee(loader)),
+        )
+        .unwrap();
 
         let root = syntax
             .tree()
diff --git a/helix-core/tests/indent.rs b/helix-core/tests/indent.rs
index de1434f7..53265e0b 100644
--- a/helix-core/tests/indent.rs
+++ b/helix-core/tests/indent.rs
@@ -1,10 +1,11 @@
+use arc_swap::ArcSwap;
 use helix_core::{
     indent::{indent_level_for_line, treesitter_indent_for_pos, IndentStyle},
     syntax::{Configuration, Loader},
     Syntax,
 };
 use ropey::Rope;
-use std::{ops::Range, path::PathBuf, process::Command};
+use std::{ops::Range, path::PathBuf, process::Command, sync::Arc};
 
 #[test]
 fn test_treesitter_indent_rust() {
@@ -197,7 +198,12 @@ fn test_treesitter_indent(
     let indent_style = IndentStyle::from_str(&language_config.indent.as_ref().unwrap().unit);
     let highlight_config = language_config.highlight_config(&[]).unwrap();
     let text = doc.slice(..);
-    let syntax = Syntax::new(text, highlight_config, std::sync::Arc::new(loader)).unwrap();
+    let syntax = Syntax::new(
+        text,
+        highlight_config,
+        Arc::new(ArcSwap::from_pointee(loader)),
+    )
+    .unwrap();
     let indent_query = language_config.indent_query().unwrap();
 
     for i in 0..doc.len_lines() {
diff --git a/helix-lsp/Cargo.toml b/helix-lsp/Cargo.toml
index 2bdd5cfc..4284b052 100644
--- a/helix-lsp/Cargo.toml
+++ b/helix-lsp/Cargo.toml
@@ -30,3 +30,4 @@ thiserror = "1.0"
 tokio = { version = "1.36", features = ["rt", "rt-multi-thread", "io-util", "io-std", "time", "process", "macros", "fs", "parking_lot", "sync"] }
 tokio-stream = "0.1.14"
 parking_lot = "0.12.1"
+arc-swap = "1"
diff --git a/helix-lsp/src/lib.rs b/helix-lsp/src/lib.rs
index 05764418..c58d967b 100644
--- a/helix-lsp/src/lib.rs
+++ b/helix-lsp/src/lib.rs
@@ -5,6 +5,7 @@ pub mod jsonrpc;
 pub mod snippet;
 mod transport;
 
+use arc_swap::ArcSwap;
 pub use client::Client;
 pub use futures_executor::block_on;
 pub use jsonrpc::Call;
@@ -640,14 +641,14 @@ impl Notification {
 #[derive(Debug)]
 pub struct Registry {
     inner: HashMap<LanguageServerName, Vec<Arc<Client>>>,
-    syn_loader: Arc<helix_core::syntax::Loader>,
+    syn_loader: Arc<ArcSwap<helix_core::syntax::Loader>>,
     counter: usize,
     pub incoming: SelectAll<UnboundedReceiverStream<(usize, Call)>>,
     pub file_event_handler: file_event::Handler,
 }
 
 impl Registry {
-    pub fn new(syn_loader: Arc<helix_core::syntax::Loader>) -> Self {
+    pub fn new(syn_loader: Arc<ArcSwap<helix_core::syntax::Loader>>) -> Self {
         Self {
             inner: HashMap::new(),
             syn_loader,
@@ -681,8 +682,8 @@ impl Registry {
         root_dirs: &[PathBuf],
         enable_snippets: bool,
     ) -> Result<Option<Arc<Client>>> {
-        let config = self
-            .syn_loader
+        let syn_loader = self.syn_loader.load();
+        let config = syn_loader
             .language_server_configs()
             .get(&name)
             .ok_or_else(|| anyhow::anyhow!("Language server '{name}' not defined"))?;
diff --git a/helix-term/src/application.rs b/helix-term/src/application.rs
index b844b5f0..30df3981 100644
--- a/helix-term/src/application.rs
+++ b/helix-term/src/application.rs
@@ -66,7 +66,7 @@ pub struct Application {
     #[allow(dead_code)]
     theme_loader: Arc<theme::Loader>,
     #[allow(dead_code)]
-    syn_loader: Arc<syntax::Loader>,
+    syn_loader: Arc<ArcSwap<syntax::Loader>>,
 
     signals: Signals,
     jobs: Jobs,
@@ -122,7 +122,7 @@ impl Application {
             })
             .unwrap_or_else(|| theme_loader.default_theme(true_color));
 
-        let syn_loader = std::sync::Arc::new(lang_loader);
+        let syn_loader = Arc::new(ArcSwap::from_pointee(lang_loader));
 
         #[cfg(not(feature = "integration"))]
         let backend = CrosstermBackend::new(stdout(), &config.editor);
@@ -391,7 +391,8 @@ impl Application {
     /// refresh language config after config change
     fn refresh_language_config(&mut self) -> Result<(), Error> {
         let lang_loader = helix_core::config::user_lang_loader()?;
-        self.syn_loader = std::sync::Arc::new(lang_loader);
+
+        self.syn_loader.store(Arc::new(lang_loader));
         self.editor.syn_loader = self.syn_loader.clone();
         for document in self.editor.documents.values_mut() {
             document.detect_language(self.syn_loader.clone());
diff --git a/helix-term/src/ui/lsp.rs b/helix-term/src/ui/lsp.rs
index 7037b155..879f963e 100644
--- a/helix-term/src/ui/lsp.rs
+++ b/helix-term/src/ui/lsp.rs
@@ -1,5 +1,6 @@
 use std::sync::Arc;
 
+use arc_swap::ArcSwap;
 use helix_core::syntax;
 use helix_view::graphics::{Margin, Rect, Style};
 use tui::buffer::Buffer;
@@ -18,13 +19,17 @@ pub struct SignatureHelp {
     active_param_range: Option<(usize, usize)>,
 
     language: String,
-    config_loader: Arc<syntax::Loader>,
+    config_loader: Arc<ArcSwap<syntax::Loader>>,
 }
 
 impl SignatureHelp {
     pub const ID: &'static str = "signature-help";
 
-    pub fn new(signature: String, language: String, config_loader: Arc<syntax::Loader>) -> Self {
+    pub fn new(
+        signature: String,
+        language: String,
+        config_loader: Arc<ArcSwap<syntax::Loader>>,
+    ) -> Self {
         Self {
             signature,
             signature_doc: None,
diff --git a/helix-term/src/ui/markdown.rs b/helix-term/src/ui/markdown.rs
index 5cf530ad..749d5850 100644
--- a/helix-term/src/ui/markdown.rs
+++ b/helix-term/src/ui/markdown.rs
@@ -1,4 +1,5 @@
 use crate::compositor::{Component, Context};
+use arc_swap::ArcSwap;
 use tui::{
     buffer::Buffer as Surface,
     text::{Span, Spans, Text},
@@ -31,7 +32,7 @@ pub fn highlighted_code_block<'a>(
     text: &str,
     language: &str,
     theme: Option<&Theme>,
-    config_loader: Arc<syntax::Loader>,
+    config_loader: Arc<ArcSwap<syntax::Loader>>,
     additional_highlight_spans: Option<Vec<(usize, std::ops::Range<usize>)>>,
 ) -> Text<'a> {
     let mut spans = Vec::new();
@@ -48,6 +49,7 @@ pub fn highlighted_code_block<'a>(
 
     let ropeslice = RopeSlice::from(text);
     let syntax = config_loader
+        .load()
         .language_configuration_for_injection_string(&InjectionLanguageMarker::Name(
             language.into(),
         ))
@@ -121,7 +123,7 @@ pub fn highlighted_code_block<'a>(
 pub struct Markdown {
     contents: String,
 
-    config_loader: Arc<syntax::Loader>,
+    config_loader: Arc<ArcSwap<syntax::Loader>>,
 }
 
 // TODO: pre-render and self reference via Pin
@@ -140,7 +142,7 @@ impl Markdown {
     ];
     const INDENT: &'static str = "  ";
 
-    pub fn new(contents: String, config_loader: Arc<syntax::Loader>) -> Self {
+    pub fn new(contents: String, config_loader: Arc<ArcSwap<syntax::Loader>>) -> Self {
         Self {
             contents,
             config_loader,
diff --git a/helix-term/src/ui/mod.rs b/helix-term/src/ui/mod.rs
index efa2473e..d27e8355 100644
--- a/helix-term/src/ui/mod.rs
+++ b/helix-term/src/ui/mod.rs
@@ -336,8 +336,8 @@ pub mod completers {
     pub fn language(editor: &Editor, input: &str) -> Vec<Completion> {
         let text: String = "text".into();
 
-        let language_ids = editor
-            .syn_loader
+        let loader = editor.syn_loader.load();
+        let language_ids = loader
             .language_configs()
             .map(|config| &config.language_id)
             .chain(std::iter::once(&text));
diff --git a/helix-term/src/ui/picker.rs b/helix-term/src/ui/picker.rs
index 4be5a11e..c2728888 100644
--- a/helix-term/src/ui/picker.rs
+++ b/helix-term/src/ui/picker.rs
@@ -461,14 +461,17 @@ impl<T: Item + 'static> Picker<T> {
 
         // Then attempt to highlight it if it has no language set
         if doc.language_config().is_none() {
-            if let Some(language_config) = doc.detect_language_config(&cx.editor.syn_loader) {
+            if let Some(language_config) = doc.detect_language_config(&cx.editor.syn_loader.load())
+            {
                 doc.language = Some(language_config.clone());
                 let text = doc.text().clone();
                 let loader = cx.editor.syn_loader.clone();
                 let job = tokio::task::spawn_blocking(move || {
-                    let syntax = language_config.highlight_config(&loader.scopes()).and_then(
-                        |highlight_config| Syntax::new(text.slice(..), highlight_config, loader),
-                    );
+                    let syntax = language_config
+                        .highlight_config(&loader.load().scopes())
+                        .and_then(|highlight_config| {
+                            Syntax::new(text.slice(..), highlight_config, loader)
+                        });
                     let callback = move |editor: &mut Editor, compositor: &mut Compositor| {
                         let Some(syntax) = syntax else {
                             log::info!("highlighting picker item failed");
diff --git a/helix-term/src/ui/prompt.rs b/helix-term/src/ui/prompt.rs
index 3764bba6..a6ee7f05 100644
--- a/helix-term/src/ui/prompt.rs
+++ b/helix-term/src/ui/prompt.rs
@@ -1,5 +1,6 @@
 use crate::compositor::{Component, Compositor, Context, Event, EventResult};
 use crate::{alt, ctrl, key, shift, ui};
+use arc_swap::ArcSwap;
 use helix_core::syntax;
 use helix_view::input::KeyEvent;
 use helix_view::keyboard::KeyCode;
@@ -34,7 +35,7 @@ pub struct Prompt {
     callback_fn: CallbackFn,
     pub doc_fn: DocFn,
     next_char_handler: Option<PromptCharHandler>,
-    language: Option<(&'static str, Arc<syntax::Loader>)>,
+    language: Option<(&'static str, Arc<ArcSwap<syntax::Loader>>)>,
 }
 
 #[derive(Clone, Copy, PartialEq, Eq)]
@@ -98,7 +99,11 @@ impl Prompt {
         self
     }
 
-    pub fn with_language(mut self, language: &'static str, loader: Arc<syntax::Loader>) -> Self {
+    pub fn with_language(
+        mut self,
+        language: &'static str,
+        loader: Arc<ArcSwap<syntax::Loader>>,
+    ) -> Self {
         self.language = Some((language, loader));
         self
     }
diff --git a/helix-view/src/document.rs b/helix-view/src/document.rs
index 33137c6c..4e7b1de9 100644
--- a/helix-view/src/document.rs
+++ b/helix-view/src/document.rs
@@ -681,7 +681,7 @@ impl Document {
     pub fn open(
         path: &Path,
         encoding: Option<&'static Encoding>,
-        config_loader: Option<Arc<syntax::Loader>>,
+        config_loader: Option<Arc<ArcSwap<syntax::Loader>>>,
         config: Arc<dyn DynAccess<Config>>,
     ) -> Result<Self, Error> {
         // Open the file if it exists, otherwise assume it is a new file (and thus empty).
@@ -922,10 +922,11 @@ impl Document {
     }
 
     /// Detect the programming language based on the file type.
-    pub fn detect_language(&mut self, config_loader: Arc<syntax::Loader>) {
+    pub fn detect_language(&mut self, config_loader: Arc<ArcSwap<syntax::Loader>>) {
+        let loader = config_loader.load();
         self.set_language(
-            self.detect_language_config(&config_loader),
-            Some(config_loader),
+            self.detect_language_config(&loader),
+            Some(Arc::clone(&config_loader)),
         );
     }
 
@@ -1059,10 +1060,12 @@ impl Document {
     pub fn set_language(
         &mut self,
         language_config: Option<Arc<helix_core::syntax::LanguageConfiguration>>,
-        loader: Option<Arc<helix_core::syntax::Loader>>,
+        loader: Option<Arc<ArcSwap<helix_core::syntax::Loader>>>,
     ) {
         if let (Some(language_config), Some(loader)) = (language_config, loader) {
-            if let Some(highlight_config) = language_config.highlight_config(&loader.scopes()) {
+            if let Some(highlight_config) =
+                language_config.highlight_config(&(*loader).load().scopes())
+            {
                 self.syntax = Syntax::new(self.text.slice(..), highlight_config, loader);
             }
 
@@ -1078,9 +1081,10 @@ impl Document {
     pub fn set_language_by_language_id(
         &mut self,
         language_id: &str,
-        config_loader: Arc<syntax::Loader>,
+        config_loader: Arc<ArcSwap<syntax::Loader>>,
     ) -> anyhow::Result<()> {
-        let language_config = config_loader
+        let language_config = (*config_loader)
+            .load()
             .language_config_for_language_id(language_id)
             .ok_or_else(|| anyhow!("invalid language id: {}", language_id))?;
         self.set_language(Some(language_config), Some(config_loader));
diff --git a/helix-view/src/editor.rs b/helix-view/src/editor.rs
index 0fa6d67c..68b74cf0 100644
--- a/helix-view/src/editor.rs
+++ b/helix-view/src/editor.rs
@@ -50,7 +50,10 @@ use helix_stdx::path::canonicalize;
 
 use serde::{ser::SerializeMap, Deserialize, Deserializer, Serialize, Serializer};
 
-use arc_swap::access::{DynAccess, DynGuard};
+use arc_swap::{
+    access::{DynAccess, DynGuard},
+    ArcSwap,
+};
 
 fn deserialize_duration_millis<'de, D>(deserializer: D) -> Result<Duration, D::Error>
 where
@@ -918,7 +921,7 @@ pub struct Editor {
     pub debugger_events: SelectAll<UnboundedReceiverStream<dap::Payload>>,
     pub breakpoints: HashMap<PathBuf, Vec<Breakpoint>>,
 
-    pub syn_loader: Arc<syntax::Loader>,
+    pub syn_loader: Arc<ArcSwap<syntax::Loader>>,
     pub theme_loader: Arc<theme::Loader>,
     /// last_theme is used for theme previews. We store the current theme here,
     /// and if previewing is cancelled, we can return to it.
@@ -1029,7 +1032,7 @@ impl Editor {
     pub fn new(
         mut area: Rect,
         theme_loader: Arc<theme::Loader>,
-        syn_loader: Arc<syntax::Loader>,
+        syn_loader: Arc<ArcSwap<syntax::Loader>>,
         config: Arc<dyn DynAccess<Config>>,
         handlers: Handlers,
     ) -> Self {
@@ -1190,7 +1193,7 @@ impl Editor {
         }
 
         let scopes = theme.scopes();
-        self.syn_loader.set_scopes(scopes.to_vec());
+        (*self.syn_loader).load().set_scopes(scopes.to_vec());
 
         match preview {
             ThemeAction::Preview => {