diff --git a/Cargo.lock b/Cargo.lock
index af7fd610dec38..80b4203938bdb 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -2768,7 +2768,6 @@ dependencies = [
  "language",
  "menu",
  "notifications",
- "parking_lot",
  "picker",
  "pretty_assertions",
  "project",
diff --git a/crates/assistant/src/inline_assistant.rs b/crates/assistant/src/inline_assistant.rs
index 9c95b09854a90..9886ee4b8d0df 100644
--- a/crates/assistant/src/inline_assistant.rs
+++ b/crates/assistant/src/inline_assistant.rs
@@ -47,6 +47,7 @@ use std::{
     iter, mem,
     ops::{Range, RangeInclusive},
     pin::Pin,
+    rc::Rc,
     sync::Arc,
     task::{self, Poll},
     time::{Duration, Instant},
@@ -174,7 +175,7 @@ impl InlineAssistant {
         if let Some(editor) = item.act_as::<Editor>(cx) {
             editor.update(cx, |editor, cx| {
                 editor.push_code_action_provider(
-                    Arc::new(AssistantCodeActionProvider {
+                    Rc::new(AssistantCodeActionProvider {
                         editor: cx.view().downgrade(),
                         workspace: workspace.downgrade(),
                     }),
diff --git a/crates/assistant/src/slash_command.rs b/crates/assistant/src/slash_command.rs
index 9e74729faefb1..73f5cfc2e61af 100644
--- a/crates/assistant/src/slash_command.rs
+++ b/crates/assistant/src/slash_command.rs
@@ -7,11 +7,13 @@ use editor::{CompletionProvider, Editor};
 use fuzzy::{match_strings, StringMatchCandidate};
 use gpui::{AppContext, Model, Task, ViewContext, WeakView, WindowContext};
 use language::{Anchor, Buffer, CodeLabel, Documentation, HighlightId, LanguageServerId, ToPoint};
-use parking_lot::{Mutex, RwLock};
+use parking_lot::Mutex;
 use project::CompletionIntent;
 use rope::Point;
 use std::{
+    cell::RefCell,
     ops::Range,
+    rc::Rc,
     sync::{
         atomic::{AtomicBool, Ordering::SeqCst},
         Arc,
@@ -322,7 +324,7 @@ impl CompletionProvider for SlashCommandCompletionProvider {
         &self,
         _: Model<Buffer>,
         _: Vec<usize>,
-        _: Arc<RwLock<Box<[project::Completion]>>>,
+        _: Rc<RefCell<Box<[project::Completion]>>>,
         _: &mut ViewContext<Editor>,
     ) -> Task<Result<bool>> {
         Task::ready(Ok(true))
diff --git a/crates/assistant2/src/inline_assistant.rs b/crates/assistant2/src/inline_assistant.rs
index 45d1fa9a691a7..4d4f6aaaf6ef0 100644
--- a/crates/assistant2/src/inline_assistant.rs
+++ b/crates/assistant2/src/inline_assistant.rs
@@ -45,6 +45,7 @@ use std::{
     iter, mem,
     ops::{Range, RangeInclusive},
     pin::Pin,
+    rc::Rc,
     sync::Arc,
     task::{self, Poll},
     time::Instant,
@@ -178,7 +179,7 @@ impl InlineAssistant {
         if let Some(editor) = item.act_as::<Editor>(cx) {
             editor.update(cx, |editor, cx| {
                 editor.push_code_action_provider(
-                    Arc::new(AssistantCodeActionProvider {
+                    Rc::new(AssistantCodeActionProvider {
                         editor: cx.view().downgrade(),
                         workspace: workspace.downgrade(),
                     }),
diff --git a/crates/collab_ui/Cargo.toml b/crates/collab_ui/Cargo.toml
index 3cc8f25b18a45..005cce6d7d2c5 100644
--- a/crates/collab_ui/Cargo.toml
+++ b/crates/collab_ui/Cargo.toml
@@ -44,7 +44,6 @@ gpui.workspace = true
 language.workspace = true
 menu.workspace = true
 notifications.workspace = true
-parking_lot.workspace = true
 picker.workspace = true
 project.workspace = true
 release_channel.workspace = true
diff --git a/crates/collab_ui/src/chat_panel/message_editor.rs b/crates/collab_ui/src/chat_panel/message_editor.rs
index c116660ded5d5..1dd1b4e0bc379 100644
--- a/crates/collab_ui/src/chat_panel/message_editor.rs
+++ b/crates/collab_ui/src/chat_panel/message_editor.rs
@@ -12,10 +12,15 @@ use language::{
     language_settings::SoftWrap, Anchor, Buffer, BufferSnapshot, CodeLabel, LanguageRegistry,
     LanguageServerId, ToOffset,
 };
-use parking_lot::RwLock;
 use project::{search::SearchQuery, Completion};
 use settings::Settings;
-use std::{ops::Range, sync::Arc, sync::LazyLock, time::Duration};
+use std::{
+    cell::RefCell,
+    ops::Range,
+    rc::Rc,
+    sync::{Arc, LazyLock},
+    time::Duration,
+};
 use theme::ThemeSettings;
 use ui::{prelude::*, TextSize};
 
@@ -68,7 +73,7 @@ impl CompletionProvider for MessageEditorCompletionProvider {
         &self,
         _buffer: Model<Buffer>,
         _completion_indices: Vec<usize>,
-        _completions: Arc<RwLock<Box<[Completion]>>>,
+        _completions: Rc<RefCell<Box<[Completion]>>>,
         _cx: &mut ViewContext<Editor>,
     ) -> Task<anyhow::Result<bool>> {
         Task::ready(Ok(false))
diff --git a/crates/editor/src/code_context_menus.rs b/crates/editor/src/code_context_menus.rs
index 646313262fc0e..bf19f2a00e86a 100644
--- a/crates/editor/src/code_context_menus.rs
+++ b/crates/editor/src/code_context_menus.rs
@@ -1,4 +1,5 @@
-use std::{cell::Cell, cmp::Reverse, ops::Range, sync::Arc};
+use std::cell::RefCell;
+use std::{cell::Cell, cmp::Reverse, ops::Range, rc::Rc};
 
 use fuzzy::{StringMatch, StringMatchCandidate};
 use gpui::{
@@ -11,7 +12,6 @@ use language::{CodeLabel, Documentation};
 use lsp::LanguageServerId;
 use multi_buffer::{Anchor, ExcerptId};
 use ordered_float::OrderedFloat;
-use parking_lot::RwLock;
 use project::{CodeAction, Completion, TaskSourceKind};
 use task::ResolvedTask;
 use ui::{
@@ -137,9 +137,9 @@ pub struct CompletionsMenu {
     sort_completions: bool,
     pub initial_position: Anchor,
     pub buffer: Model<Buffer>,
-    pub completions: Arc<RwLock<Box<[Completion]>>>,
-    match_candidates: Arc<[StringMatchCandidate]>,
-    pub matches: Arc<[StringMatch]>,
+    pub completions: Rc<RefCell<Box<[Completion]>>>,
+    match_candidates: Rc<[StringMatchCandidate]>,
+    pub matches: Rc<[StringMatch]>,
     pub selected_item: usize,
     scroll_handle: UniformListScrollHandle,
     resolve_completions: bool,
@@ -169,7 +169,7 @@ impl CompletionsMenu {
             initial_position,
             buffer,
             show_completion_documentation,
-            completions: Arc::new(RwLock::new(completions)),
+            completions: RefCell::new(completions).into(),
             match_candidates,
             matches: Vec::new().into(),
             selected_item: 0,
@@ -223,7 +223,7 @@ impl CompletionsMenu {
             sort_completions,
             initial_position: selection.start,
             buffer,
-            completions: Arc::new(RwLock::new(completions)),
+            completions: RefCell::new(completions).into(),
             match_candidates,
             matches,
             selected_item: 0,
@@ -329,13 +329,13 @@ impl CompletionsMenu {
         workspace: Option<WeakView<Workspace>>,
         cx: &mut ViewContext<Editor>,
     ) -> AnyElement {
+        let completions = self.completions.borrow_mut();
         let show_completion_documentation = self.show_completion_documentation;
         let widest_completion_ix = self
             .matches
             .iter()
             .enumerate()
             .max_by_key(|(_, mat)| {
-                let completions = self.completions.read();
                 let completion = &completions[mat.candidate_id];
                 let documentation = &completion.documentation;
 
@@ -350,14 +350,12 @@ impl CompletionsMenu {
             })
             .map(|(ix, _)| ix);
 
-        let completions = self.completions.clone();
-        let matches = self.matches.clone();
         let selected_item = self.selected_item;
         let style = style.clone();
 
         let multiline_docs = if show_completion_documentation {
             let mat = &self.matches[selected_item];
-            match &self.completions.read()[mat.candidate_id].documentation {
+            match &completions[mat.candidate_id].documentation {
                 Some(Documentation::MultiLinePlainText(text)) => {
                     Some(div().child(SharedString::from(text.clone())))
                 }
@@ -401,13 +399,16 @@ impl CompletionsMenu {
                 .occlude()
         });
 
+        drop(completions);
+        let completions = self.completions.clone();
+        let matches = self.matches.clone();
         let list = uniform_list(
             cx.view().clone(),
             "completions",
             matches.len(),
             move |_editor, range, cx| {
                 let start_ix = range.start;
-                let completions_guard = completions.read();
+                let completions_guard = completions.borrow_mut();
 
                 matches[range]
                     .iter()
@@ -548,7 +549,7 @@ impl CompletionsMenu {
             }
         }
 
-        let completions = self.completions.read();
+        let completions = self.completions.borrow_mut();
         if self.sort_completions {
             matches.sort_unstable_by_key(|mat| {
                 // We do want to strike a balance here between what the language server tells us
@@ -611,13 +612,13 @@ impl CompletionsMenu {
 pub struct AvailableCodeAction {
     pub excerpt_id: ExcerptId,
     pub action: CodeAction,
-    pub provider: Arc<dyn CodeActionProvider>,
+    pub provider: Rc<dyn CodeActionProvider>,
 }
 
 #[derive(Clone)]
 pub struct CodeActionContents {
-    pub tasks: Option<Arc<ResolvedTasks>>,
-    pub actions: Option<Arc<[AvailableCodeAction]>>,
+    pub tasks: Option<Rc<ResolvedTasks>>,
+    pub actions: Option<Rc<[AvailableCodeAction]>>,
 }
 
 impl CodeActionContents {
@@ -702,7 +703,7 @@ pub enum CodeActionsItem {
     CodeAction {
         excerpt_id: ExcerptId,
         action: CodeAction,
-        provider: Arc<dyn CodeActionProvider>,
+        provider: Rc<dyn CodeActionProvider>,
     },
 }
 
diff --git a/crates/editor/src/editor.rs b/crates/editor/src/editor.rs
index d3585c24fcf3c..1ab978f3566e0 100644
--- a/crates/editor/src/editor.rs
+++ b/crates/editor/src/editor.rs
@@ -127,7 +127,6 @@ pub use multi_buffer::{
 use multi_buffer::{
     ExpandExcerptDirection, MultiBufferDiffHunk, MultiBufferPoint, MultiBufferRow, ToOffsetUtf16,
 };
-use parking_lot::RwLock;
 use project::{
     lsp_store::{FormatTarget, FormatTrigger, OpenLspBufferHandle},
     project_settings::{GitGutterSetting, ProjectSettings},
@@ -606,7 +605,7 @@ pub struct Editor {
     scrollbar_marker_state: ScrollbarMarkerState,
     active_indent_guides_state: ActiveIndentGuidesState,
     nav_history: Option<ItemNavHistory>,
-    context_menu: RwLock<Option<CodeContextMenu>>,
+    context_menu: RefCell<Option<CodeContextMenu>>,
     mouse_context_menu: Option<MouseContextMenu>,
     hunk_controls_menu_handle: PopoverMenuHandle<ui::ContextMenu>,
     completion_tasks: Vec<(CompletionId, Task<Option<()>>)>,
@@ -614,7 +613,7 @@ pub struct Editor {
     auto_signature_help: Option<bool>,
     find_all_references_task_sources: Vec<Anchor>,
     next_completion_id: CompletionId,
-    available_code_actions: Option<(Location, Arc<[AvailableCodeAction]>)>,
+    available_code_actions: Option<(Location, Rc<[AvailableCodeAction]>)>,
     code_actions_task: Option<Task<Result<()>>>,
     document_highlights_task: Option<Task<()>>,
     linked_editing_range_task: Option<Task<Option<()>>>,
@@ -635,7 +634,7 @@ pub struct Editor {
     gutter_hovered: bool,
     hovered_link_state: Option<HoveredLinkState>,
     inline_completion_provider: Option<RegisteredInlineCompletionProvider>,
-    code_action_providers: Vec<Arc<dyn CodeActionProvider>>,
+    code_action_providers: Vec<Rc<dyn CodeActionProvider>>,
     active_inline_completion: Option<InlineCompletionState>,
     // enable_inline_completions is a switch that Vim can use to disable
     // inline completions based on its mode.
@@ -1192,7 +1191,7 @@ impl Editor {
         let mut code_action_providers = Vec::new();
         if let Some(project) = project.clone() {
             get_unstaged_changes_for_buffers(&project, buffer.read(cx).all_buffers(), cx);
-            code_action_providers.push(Arc::new(project) as Arc<_>);
+            code_action_providers.push(Rc::new(project) as Rc<_>);
         }
 
         let mut this = Self {
@@ -1238,7 +1237,7 @@ impl Editor {
             scrollbar_marker_state: ScrollbarMarkerState::default(),
             active_indent_guides_state: ActiveIndentGuidesState::default(),
             nav_history: None,
-            context_menu: RwLock::new(None),
+            context_menu: RefCell::new(None),
             mouse_context_menu: None,
             hunk_controls_menu_handle: PopoverMenuHandle::default(),
             completion_tasks: Default::default(),
@@ -1384,7 +1383,7 @@ impl Editor {
             key_context.add("renaming");
         }
         if self.context_menu_visible() {
-            match self.context_menu.read().as_ref() {
+            match self.context_menu.borrow().as_ref() {
                 Some(CodeContextMenu::Completions(_)) => {
                     key_context.add("menu");
                     key_context.add("showing_completions")
@@ -1886,10 +1885,9 @@ impl Editor {
 
         if local {
             let new_cursor_position = self.selections.newest_anchor().head();
-            let mut context_menu = self.context_menu.write();
+            let mut context_menu = self.context_menu.borrow_mut();
             let completion_menu = match context_menu.as_ref() {
                 Some(CodeContextMenu::Completions(menu)) => Some(menu),
-
                 _ => {
                     *context_menu = None;
                     None
@@ -1913,7 +1911,7 @@ impl Editor {
                             .await;
 
                         this.update(&mut cx, |this, cx| {
-                            let mut context_menu = this.context_menu.write();
+                            let mut context_menu = this.context_menu.borrow_mut();
                             let Some(CodeContextMenu::Completions(menu)) = context_menu.as_ref()
                             else {
                                 return;
@@ -3651,7 +3649,7 @@ impl Editor {
             return;
         };
 
-        if !self.snippet_stack.is_empty() && self.context_menu.read().as_ref().is_some() {
+        if !self.snippet_stack.is_empty() && self.context_menu.borrow().as_ref().is_some() {
             return;
         }
 
@@ -3670,7 +3668,7 @@ impl Editor {
 
         let query = Self::completion_query(&self.buffer.read(cx).read(cx), position);
 
-        let aside_was_displayed = match self.context_menu.read().deref() {
+        let aside_was_displayed = match self.context_menu.borrow().deref() {
             Some(CodeContextMenu::Completions(menu)) => menu.aside_was_displayed.get(),
             _ => false,
         };
@@ -3723,16 +3721,14 @@ impl Editor {
                 };
 
                 editor.update(&mut cx, |editor, cx| {
-                    let mut context_menu = editor.context_menu.write();
+                    let mut context_menu = editor.context_menu.borrow_mut();
                     match context_menu.as_ref() {
                         None => {}
-
                         Some(CodeContextMenu::Completions(prev_menu)) => {
                             if prev_menu.id > id {
                                 return;
                             }
                         }
-
                         _ => return,
                     }
 
@@ -3795,7 +3791,7 @@ impl Editor {
             .matches
             .get(item_ix.unwrap_or(completions_menu.selected_item))?;
         let buffer_handle = completions_menu.buffer;
-        let completions = completions_menu.completions.read();
+        let completions = completions_menu.completions.borrow_mut();
         let completion = completions.get(mat.candidate_id)?;
         cx.stop_propagation();
 
@@ -3961,7 +3957,7 @@ impl Editor {
     }
 
     pub fn toggle_code_actions(&mut self, action: &ToggleCodeActions, cx: &mut ViewContext<Self>) {
-        let mut context_menu = self.context_menu.write();
+        let mut context_menu = self.context_menu.borrow_mut();
         if let Some(CodeContextMenu::CodeActions(code_actions)) = context_menu.as_ref() {
             if code_actions.deployed_from_indicator == action.deployed_from_indicator {
                 // Toggle if we're selecting the same one
@@ -4041,7 +4037,7 @@ impl Editor {
                         };
                         let resolved_tasks =
                             tasks.zip(task_context).map(|(tasks, task_context)| {
-                                Arc::new(ResolvedTasks {
+                                Rc::new(ResolvedTasks {
                                     templates: tasks.resolve(&task_context).collect(),
                                     position: snapshot.buffer_snapshot.anchor_before(Point::new(
                                         multibuffer_point.row,
@@ -4056,7 +4052,7 @@ impl Editor {
                                 .as_ref()
                                 .map_or(true, |actions| actions.is_empty());
                         if let Ok(task) = editor.update(&mut cx, |editor, cx| {
-                            *editor.context_menu.write() =
+                            *editor.context_menu.borrow_mut() =
                                 Some(CodeContextMenu::CodeActions(CodeActionsMenu {
                                     buffer,
                                     actions: CodeActionContents {
@@ -4241,7 +4237,7 @@ impl Editor {
 
     pub fn push_code_action_provider(
         &mut self,
-        provider: Arc<dyn CodeActionProvider>,
+        provider: Rc<dyn CodeActionProvider>,
         cx: &mut ViewContext<Self>,
     ) {
         self.code_action_providers.push(provider);
@@ -5004,7 +5000,7 @@ impl Editor {
 
     pub fn context_menu_visible(&self) -> bool {
         self.context_menu
-            .read()
+            .borrow()
             .as_ref()
             .map_or(false, |menu| menu.visible())
     }
@@ -5016,7 +5012,7 @@ impl Editor {
         max_height: Pixels,
         cx: &mut ViewContext<Editor>,
     ) -> Option<(ContextMenuOrigin, AnyElement)> {
-        self.context_menu.read().as_ref().map(|menu| {
+        self.context_menu.borrow().as_ref().map(|menu| {
             menu.render(
                 cursor_position,
                 style,
@@ -5030,7 +5026,7 @@ impl Editor {
     fn hide_context_menu(&mut self, cx: &mut ViewContext<Self>) -> Option<CodeContextMenu> {
         cx.notify();
         self.completion_tasks.clear();
-        self.context_menu.write().take()
+        self.context_menu.borrow_mut().take()
     }
 
     fn show_snippet_choices(
@@ -5047,7 +5043,7 @@ impl Editor {
         let id = post_inc(&mut self.next_completion_id);
 
         if let Some(buffer) = buffer {
-            *self.context_menu.write() = Some(CodeContextMenu::Completions(
+            *self.context_menu.borrow_mut() = Some(CodeContextMenu::Completions(
                 CompletionsMenu::new_snippet_choices(id, true, choices, selection, buffer),
             ));
         }
@@ -7101,7 +7097,7 @@ impl Editor {
 
         if self
             .context_menu
-            .write()
+            .borrow_mut()
             .as_mut()
             .map(|menu| menu.select_first(self.completion_provider.as_deref(), cx))
             .unwrap_or(false)
@@ -7210,7 +7206,7 @@ impl Editor {
 
         if self
             .context_menu
-            .write()
+            .borrow_mut()
             .as_mut()
             .map(|menu| menu.select_last(self.completion_provider.as_deref(), cx))
             .unwrap_or(false)
@@ -7263,25 +7259,25 @@ impl Editor {
     }
 
     pub fn context_menu_first(&mut self, _: &ContextMenuFirst, cx: &mut ViewContext<Self>) {
-        if let Some(context_menu) = self.context_menu.write().as_mut() {
+        if let Some(context_menu) = self.context_menu.borrow_mut().as_mut() {
             context_menu.select_first(self.completion_provider.as_deref(), cx);
         }
     }
 
     pub fn context_menu_prev(&mut self, _: &ContextMenuPrev, cx: &mut ViewContext<Self>) {
-        if let Some(context_menu) = self.context_menu.write().as_mut() {
+        if let Some(context_menu) = self.context_menu.borrow_mut().as_mut() {
             context_menu.select_prev(self.completion_provider.as_deref(), cx);
         }
     }
 
     pub fn context_menu_next(&mut self, _: &ContextMenuNext, cx: &mut ViewContext<Self>) {
-        if let Some(context_menu) = self.context_menu.write().as_mut() {
+        if let Some(context_menu) = self.context_menu.borrow_mut().as_mut() {
             context_menu.select_next(self.completion_provider.as_deref(), cx);
         }
     }
 
     pub fn context_menu_last(&mut self, _: &ContextMenuLast, cx: &mut ViewContext<Self>) {
-        if let Some(context_menu) = self.context_menu.write().as_mut() {
+        if let Some(context_menu) = self.context_menu.borrow_mut().as_mut() {
             context_menu.select_last(self.completion_provider.as_deref(), cx);
         }
     }
@@ -12818,7 +12814,7 @@ impl Editor {
     }
 
     pub fn has_active_completions_menu(&self) -> bool {
-        self.context_menu.read().as_ref().map_or(false, |menu| {
+        self.context_menu.borrow().as_ref().map_or(false, |menu| {
             menu.visible() && matches!(menu, CodeContextMenu::Completions(_))
         })
     }
@@ -13314,7 +13310,7 @@ pub trait CompletionProvider {
         &self,
         buffer: Model<Buffer>,
         completion_indices: Vec<usize>,
-        completions: Arc<RwLock<Box<[Completion]>>>,
+        completions: Rc<RefCell<Box<[Completion]>>>,
         cx: &mut ViewContext<Editor>,
     ) -> Task<Result<bool>>;
 
@@ -13544,7 +13540,7 @@ impl CompletionProvider for Model<Project> {
         &self,
         buffer: Model<Buffer>,
         completion_indices: Vec<usize>,
-        completions: Arc<RwLock<Box<[Completion]>>>,
+        completions: Rc<RefCell<Box<[Completion]>>>,
         cx: &mut ViewContext<Editor>,
     ) -> Task<Result<bool>> {
         self.update(cx, |project, cx| {
diff --git a/crates/editor/src/editor_tests.rs b/crates/editor/src/editor_tests.rs
index 6994d4e9685d9..8ff7c1cacd33a 100644
--- a/crates/editor/src/editor_tests.rs
+++ b/crates/editor/src/editor_tests.rs
@@ -8342,9 +8342,9 @@ async fn test_completion(cx: &mut gpui::TestAppContext) {
         additional edit
     "});
     cx.simulate_keystroke(" ");
-    assert!(cx.editor(|e, _| e.context_menu.read().is_none()));
+    assert!(cx.editor(|e, _| e.context_menu.borrow_mut().is_none()));
     cx.simulate_keystroke("s");
-    assert!(cx.editor(|e, _| e.context_menu.read().is_none()));
+    assert!(cx.editor(|e, _| e.context_menu.borrow_mut().is_none()));
 
     cx.assert_editor_state(indoc! {"
         one.second_completion
@@ -8406,12 +8406,12 @@ async fn test_completion(cx: &mut gpui::TestAppContext) {
     });
     cx.set_state("editorˇ");
     cx.simulate_keystroke(".");
-    assert!(cx.editor(|e, _| e.context_menu.read().is_none()));
+    assert!(cx.editor(|e, _| e.context_menu.borrow_mut().is_none()));
     cx.simulate_keystroke("c");
     cx.simulate_keystroke("l");
     cx.simulate_keystroke("o");
     cx.assert_editor_state("editor.cloˇ");
-    assert!(cx.editor(|e, _| e.context_menu.read().is_none()));
+    assert!(cx.editor(|e, _| e.context_menu.borrow_mut().is_none()));
     cx.update_editor(|editor, cx| {
         editor.show_completions(&ShowCompletions { trigger: None }, cx);
     });
@@ -8468,7 +8468,8 @@ async fn test_completion_page_up_down_keys(cx: &mut gpui::TestAppContext) {
     cx.executor().run_until_parked();
 
     cx.update_editor(|editor, _| {
-        if let Some(CodeContextMenu::Completions(menu)) = editor.context_menu.read().as_ref() {
+        if let Some(CodeContextMenu::Completions(menu)) = editor.context_menu.borrow_mut().as_ref()
+        {
             assert_eq!(
                 menu.matches.iter().map(|m| &m.string).collect::<Vec<_>>(),
                 &["first", "last"]
@@ -8480,7 +8481,8 @@ async fn test_completion_page_up_down_keys(cx: &mut gpui::TestAppContext) {
 
     cx.update_editor(|editor, cx| {
         editor.move_page_down(&MovePageDown::default(), cx);
-        if let Some(CodeContextMenu::Completions(menu)) = editor.context_menu.read().as_ref() {
+        if let Some(CodeContextMenu::Completions(menu)) = editor.context_menu.borrow_mut().as_ref()
+        {
             assert!(
                 menu.selected_item == 1,
                 "expected PageDown to select the last item from the context menu"
@@ -8492,7 +8494,8 @@ async fn test_completion_page_up_down_keys(cx: &mut gpui::TestAppContext) {
 
     cx.update_editor(|editor, cx| {
         editor.move_page_up(&MovePageUp::default(), cx);
-        if let Some(CodeContextMenu::Completions(menu)) = editor.context_menu.read().as_ref() {
+        if let Some(CodeContextMenu::Completions(menu)) = editor.context_menu.borrow_mut().as_ref()
+        {
             assert!(
                 menu.selected_item == 0,
                 "expected PageUp to select the first item from the context menu"
@@ -8560,7 +8563,8 @@ async fn test_completion_sort(cx: &mut gpui::TestAppContext) {
     cx.executor().run_until_parked();
 
     cx.update_editor(|editor, _| {
-        if let Some(CodeContextMenu::Completions(menu)) = editor.context_menu.read().as_ref() {
+        if let Some(CodeContextMenu::Completions(menu)) = editor.context_menu.borrow_mut().as_ref()
+        {
             assert_eq!(
                 menu.matches.iter().map(|m| &m.string).collect::<Vec<_>>(),
                 &["r", "ret", "Range", "return"]
@@ -10704,13 +10708,13 @@ async fn test_completions_resolve_updates_labels_if_filter_text_matches(
     cx.condition(|editor, _| editor.context_menu_visible())
         .await;
     cx.update_editor(|editor, _| {
-        let context_menu = editor.context_menu.read();
+        let context_menu = editor.context_menu.borrow_mut();
         let context_menu = context_menu
             .as_ref()
             .expect("Should have the context menu deployed");
         match context_menu {
             CodeContextMenu::Completions(completions_menu) => {
-                let completions = completions_menu.completions.read();
+                let completions = completions_menu.completions.borrow_mut();
                 assert_eq!(
                     completions
                         .iter()
@@ -10761,13 +10765,13 @@ async fn test_completions_resolve_updates_labels_if_filter_text_matches(
     cx.run_until_parked();
 
     cx.update_editor(|editor, _| {
-        let context_menu = editor.context_menu.read();
+        let context_menu = editor.context_menu.borrow_mut();
         let context_menu = context_menu
             .as_ref()
             .expect("Should have the context menu deployed");
         match context_menu {
             CodeContextMenu::Completions(completions_menu) => {
-                let completions = completions_menu.completions.read();
+                let completions = completions_menu.completions.borrow_mut();
                 assert_eq!(
                     completions
                         .iter()
@@ -10954,7 +10958,7 @@ async fn test_completions_default_resolve_data_handling(cx: &mut gpui::TestAppCo
         .await;
     cx.run_until_parked();
     cx.update_editor(|editor, _| {
-        let menu = editor.context_menu.read();
+        let menu = editor.context_menu.borrow_mut();
         match menu.as_ref().expect("should have the completions menu") {
             CodeContextMenu::Completions(completions_menu) => {
                 assert_eq!(
@@ -11059,7 +11063,8 @@ async fn test_completions_in_languages_with_extra_word_characters(cx: &mut gpui:
     cx.simulate_keystroke("-");
     cx.executor().run_until_parked();
     cx.update_editor(|editor, _| {
-        if let Some(CodeContextMenu::Completions(menu)) = editor.context_menu.read().as_ref() {
+        if let Some(CodeContextMenu::Completions(menu)) = editor.context_menu.borrow_mut().as_ref()
+        {
             assert_eq!(
                 menu.matches.iter().map(|m| &m.string).collect::<Vec<_>>(),
                 &["bg-red", "bg-blue", "bg-yellow"]
@@ -11072,7 +11077,8 @@ async fn test_completions_in_languages_with_extra_word_characters(cx: &mut gpui:
     cx.simulate_keystroke("l");
     cx.executor().run_until_parked();
     cx.update_editor(|editor, _| {
-        if let Some(CodeContextMenu::Completions(menu)) = editor.context_menu.read().as_ref() {
+        if let Some(CodeContextMenu::Completions(menu)) = editor.context_menu.borrow_mut().as_ref()
+        {
             assert_eq!(
                 menu.matches.iter().map(|m| &m.string).collect::<Vec<_>>(),
                 &["bg-blue", "bg-yellow"]
@@ -11088,7 +11094,8 @@ async fn test_completions_in_languages_with_extra_word_characters(cx: &mut gpui:
     cx.simulate_keystroke("l");
     cx.executor().run_until_parked();
     cx.update_editor(|editor, _| {
-        if let Some(CodeContextMenu::Completions(menu)) = editor.context_menu.read().as_ref() {
+        if let Some(CodeContextMenu::Completions(menu)) = editor.context_menu.borrow_mut().as_ref()
+        {
             assert_eq!(
                 menu.matches.iter().map(|m| &m.string).collect::<Vec<_>>(),
                 &["bg-yellow"]
diff --git a/crates/editor/src/element.rs b/crates/editor/src/element.rs
index c0431f6a06c62..d36885459ad53 100644
--- a/crates/editor/src/element.rs
+++ b/crates/editor/src/element.rs
@@ -1686,7 +1686,7 @@ impl EditorElement {
                     deployed_from_indicator,
                     actions,
                     ..
-                })) = editor.context_menu.read().as_ref()
+                })) = editor.context_menu.borrow().as_ref()
                 {
                     actions
                         .tasks
@@ -1777,7 +1777,7 @@ impl EditorElement {
             if let Some(crate::CodeContextMenu::CodeActions(CodeActionsMenu {
                 deployed_from_indicator,
                 ..
-            })) = editor.context_menu.read().as_ref()
+            })) = editor.context_menu.borrow().as_ref()
             {
                 active = deployed_from_indicator.map_or(true, |indicator_row| indicator_row == row);
             };
diff --git a/crates/project/src/lsp_store.rs b/crates/project/src/lsp_store.rs
index 92a4aee225638..55abc6811e241 100644
--- a/crates/project/src/lsp_store.rs
+++ b/crates/project/src/lsp_store.rs
@@ -52,7 +52,7 @@ use lsp::{
     WillRenameFiles, WorkDoneProgressCancelParams, WorkspaceFolder,
 };
 use node_runtime::read_package_installed_version;
-use parking_lot::{Mutex, RwLock};
+use parking_lot::Mutex;
 use postage::watch;
 use rand::prelude::*;
 
@@ -65,12 +65,14 @@ use smol::channel::Sender;
 use snippet::Snippet;
 use std::{
     any::Any,
+    cell::RefCell,
     cmp::Ordering,
     convert::TryInto,
     ffi::OsStr,
     iter, mem,
     ops::{ControlFlow, Range},
     path::{self, Path, PathBuf},
+    rc::Rc,
     str,
     sync::Arc,
     time::{Duration, Instant},
@@ -4137,7 +4139,7 @@ impl LspStore {
         &self,
         buffer: Model<Buffer>,
         completion_indices: Vec<usize>,
-        completions: Arc<RwLock<Box<[Completion]>>>,
+        completions: Rc<RefCell<Box<[Completion]>>>,
         cx: &mut ModelContext<Self>,
     ) -> Task<Result<bool>> {
         let client = self.upstream_client();
@@ -4151,8 +4153,8 @@ impl LspStore {
             if let Some((client, project_id)) = client {
                 for completion_index in completion_indices {
                     let (server_id, completion) = {
-                        let completions_guard = completions.read();
-                        let completion = &completions_guard[completion_index];
+                        let completions = completions.borrow_mut();
+                        let completion = &completions[completion_index];
                         did_resolve = true;
                         let server_id = completion.server_id;
                         let completion = completion.lsp_completion.clone();
@@ -4175,8 +4177,8 @@ impl LspStore {
             } else {
                 for completion_index in completion_indices {
                     let (server_id, completion) = {
-                        let completions_guard = completions.read();
-                        let completion = &completions_guard[completion_index];
+                        let completions = completions.borrow_mut();
+                        let completion = &completions[completion_index];
                         let server_id = completion.server_id;
                         let completion = completion.lsp_completion.clone();
 
@@ -4218,7 +4220,7 @@ impl LspStore {
         server: Arc<lsp::LanguageServer>,
         adapter: Arc<CachedLspAdapter>,
         snapshot: &BufferSnapshot,
-        completions: Arc<RwLock<Box<[Completion]>>>,
+        completions: Rc<RefCell<Box<[Completion]>>>,
         completion_index: usize,
         completion: lsp::CompletionItem,
         language_registry: Arc<LanguageRegistry>,
@@ -4246,11 +4248,11 @@ impl LspStore {
             )
             .await;
 
-            let mut completions = completions.write();
+            let mut completions = completions.borrow_mut();
             let completion = &mut completions[completion_index];
             completion.documentation = Some(documentation);
         } else {
-            let mut completions = completions.write();
+            let mut completions = completions.borrow_mut();
             let completion = &mut completions[completion_index];
             completion.documentation = Some(Documentation::Undocumented);
         }
@@ -4265,7 +4267,7 @@ impl LspStore {
             if let Some((old_range, mut new_text)) = edit {
                 LineEnding::normalize(&mut new_text);
 
-                let mut completions = completions.write();
+                let mut completions = completions.borrow_mut();
                 let completion = &mut completions[completion_index];
 
                 completion.new_text = new_text;
@@ -4274,7 +4276,7 @@ impl LspStore {
         }
         if completion_item.insert_text_format == Some(InsertTextFormat::SNIPPET) {
             // vtsls might change the type of completion after resolution.
-            let mut completions = completions.write();
+            let mut completions = completions.borrow_mut();
             let completion = &mut completions[completion_index];
             if completion_item.insert_text_format != completion.lsp_completion.insert_text_format {
                 completion.lsp_completion.insert_text_format = completion_item.insert_text_format;
@@ -4300,7 +4302,7 @@ impl LspStore {
             )
         });
 
-        let mut completions = completions.write();
+        let mut completions = completions.borrow_mut();
         let completion = &mut completions[completion_index];
         completion.lsp_completion = completion_item;
         if completion.label.filter_text() == new_label.filter_text() {
@@ -4322,7 +4324,7 @@ impl LspStore {
         project_id: u64,
         server_id: LanguageServerId,
         buffer_id: BufferId,
-        completions: Arc<RwLock<Box<[Completion]>>>,
+        completions: Rc<RefCell<Box<[Completion]>>>,
         completion_index: usize,
         completion: lsp::CompletionItem,
         client: AnyProtoClient,
@@ -4360,7 +4362,7 @@ impl LspStore {
             Documentation::MultiLinePlainText(response.documentation)
         };
 
-        let mut completions = completions.write();
+        let mut completions = completions.borrow_mut();
         let completion = &mut completions[completion_index];
         completion.documentation = Some(documentation);
         completion.lsp_completion = lsp_completion;
diff --git a/crates/project/src/project.rs b/crates/project/src/project.rs
index 1040ae3bec0bc..50c9db8fb1aef 100644
--- a/crates/project/src/project.rs
+++ b/crates/project/src/project.rs
@@ -57,7 +57,7 @@ use lsp::{
 };
 use lsp_command::*;
 use node_runtime::NodeRuntime;
-use parking_lot::{Mutex, RwLock};
+use parking_lot::Mutex;
 pub use prettier_store::PrettierStore;
 use project_settings::{ProjectSettings, SettingsObserver, SettingsObserverEvent};
 use remote::{SshConnectionOptions, SshRemoteClient};
@@ -73,8 +73,10 @@ use snippet::Snippet;
 use snippet_provider::SnippetProvider;
 use std::{
     borrow::Cow,
+    cell::RefCell,
     ops::Range,
     path::{Component, Path, PathBuf},
+    rc::Rc,
     str,
     sync::Arc,
     time::Duration,
@@ -2872,7 +2874,7 @@ impl Project {
         &self,
         buffer: Model<Buffer>,
         completion_indices: Vec<usize>,
-        completions: Arc<RwLock<Box<[Completion]>>>,
+        completions: Rc<RefCell<Box<[Completion]>>>,
         cx: &mut ModelContext<Self>,
     ) -> Task<Result<bool>> {
         self.lsp_store.update(cx, |lsp_store, cx| {