Remove OS Thread from Atomics Wait Async (#989)

Co-authored-by: Aapo Alasuutari <aapo.alasuutari@gmail.com>

Author: komyg

.github/workflows/ci.yml

@@ -37,22 +37,30 @@ jobs:
       - name: Install Rust toolchain
         uses: dtolnay/rust-toolchain@nightly
         with:
-          toolchain: nightly-2025-10-31
+          toolchain: nightly-2026-05-28
           components: rustfmt, clippy, llvm-tools-preview, rustc-dev
       - name: Cache on ${{ github.ref_name }}
         uses: Swatinem/rust-cache@v2
         with:
           shared-key: warm
-      - name: Install Dylint
-        uses: taiki-e/install-action@v2
+      # Build Dylint from crates.io instead of using prebuilt binaries: the
+      # binaries attached to dylint's GitHub releases (since v6.0.1) are built
+      # inside the dylint repo and bake in a path dependency on
+      # /home/runner/work/dylint/dylint/driver, which breaks driver builds.
+      - name: Install cargo-dylint
+        uses: taiki-e/cache-cargo-install-action@v2
         with:
-          tool: cargo-dylint,dylint-link
+          tool: cargo-dylint@6.0.1
+      - name: Install dylint-link
+        uses: taiki-e/cache-cargo-install-action@v2
+        with:
+          tool: dylint-link@6.0.1
       - name: Check formatting
         run: cargo fmt --check
       - name: Clippy
         run: |
           cargo +stable clippy --all-targets -- -D warnings
-          cargo +nightly-2025-10-31 clippy --all-targets --all-features -- -D warnings
+          cargo +nightly-2026-05-28 clippy --all-targets --all-features -- -D warnings
       - name: Dylint tests
         working-directory: nova_lint
         run: cargo test

Cargo.toml

@@ -22,7 +22,7 @@ console = "=0.16.3"
 ctrlc = "=3.5.2"
 ecmascript_atomics = { version = "=0.2.3" }
 fast-float = "=0.2.0"
-hashbrown = "=0.17.0"
+hashbrown = "=0.17.1"
 lexical = { version = "=7.0.5", default-features = false, features = [
     "std",
     "write-integers",

nova_cli/src/lib/child_hooks.rs

@@ -10,7 +10,7 @@ use std::{
     collections::VecDeque,
     sync::{atomic::AtomicBool, mpsc},
     thread,
-    time::Duration,
+    time::{Duration, Instant},
 };
 
 use nova_vm::ecmascript::{HostHooks, Job};
@@ -19,7 +19,7 @@ use crate::{ChildToHostMessage, HostToChildMessage};
 
 pub struct CliChildHooks {
     promise_job_queue: RefCell<VecDeque<Job>>,
-    macrotask_queue: RefCell<Vec<Job>>,
+    macrotask_queue: RefCell<Vec<(Option<Instant>, Job)>>,
     pub(crate) receiver: mpsc::Receiver<HostToChildMessage>,
     pub(crate) host_sender: mpsc::SyncSender<ChildToHostMessage>,
     ready_to_leave: AtomicBool,
@@ -78,9 +78,11 @@ impl CliChildHooks {
         let mut counter = 0u8;
         while !off_thread_job_queue.is_empty() {
             counter = counter.wrapping_add(1);
-            for (i, job) in off_thread_job_queue.iter().enumerate() {
-                if job.is_finished() {
-                    let job = off_thread_job_queue.swap_remove(i);
+            let now = Instant::now();
+            for (i, (deadline, job)) in off_thread_job_queue.iter().enumerate() {
+                let deadline_reached = deadline.is_none_or(|d| now >= d);
+                if deadline_reached && job.is_finished() {
+                    let (_, job) = off_thread_job_queue.swap_remove(i);
                     return Some(job);
                 }
             }
@@ -96,14 +98,19 @@ impl CliChildHooks {
 
 impl HostHooks for CliChildHooks {
     fn enqueue_generic_job(&self, job: Job) {
-        self.macrotask_queue.borrow_mut().push(job);
+        self.macrotask_queue.borrow_mut().push((None, job));
     }
 
     fn enqueue_promise_job(&self, job: Job) {
         self.promise_job_queue.borrow_mut().push_back(job);
     }
 
-    fn enqueue_timeout_job(&self, _timeout_job: Job, _milliseconds: u64) {}
+    fn enqueue_timeout_job(&self, timeout_job: Job, milliseconds: u64) {
+        let deadline = Instant::now() + Duration::from_millis(milliseconds);
+        self.macrotask_queue
+            .borrow_mut()
+            .push((Some(deadline), timeout_job));
+    }
 
     fn get_host_data(&self) -> &dyn std::any::Any {
         self

nova_cli/src/lib/host_hooks.rs

@@ -5,8 +5,14 @@
 //! The [`HostHooks`] implementation for the main thread.
 
 use std::{
-    cell::RefCell, collections::VecDeque, fmt::Debug, path::PathBuf, rc::Rc, sync::mpsc, thread,
-    time::Duration,
+    cell::RefCell,
+    collections::VecDeque,
+    fmt::Debug,
+    path::PathBuf,
+    rc::Rc,
+    sync::mpsc,
+    thread,
+    time::{Duration, Instant},
 };
 
 use nova_vm::{
@@ -29,7 +35,7 @@ pub enum ChildToHostMessage {
 
 pub struct CliHostHooks {
     promise_job_queue: RefCell<VecDeque<Job>>,
-    macrotask_queue: RefCell<Vec<Job>>,
+    macrotask_queue: RefCell<Vec<(Option<Instant>, Job)>>,
     pub(crate) receiver: mpsc::Receiver<ChildToHostMessage>,
     pub(crate) own_sender: mpsc::SyncSender<ChildToHostMessage>,
     pub(crate) child_senders: RefCell<Vec<mpsc::SyncSender<HostToChildMessage>>>,
@@ -83,9 +89,11 @@ impl CliHostHooks {
         let mut counter = 0u8;
         while !off_thread_job_queue.is_empty() {
             counter = counter.wrapping_add(1);
-            for (i, job) in off_thread_job_queue.iter().enumerate() {
-                if job.is_finished() {
-                    let job = off_thread_job_queue.swap_remove(i);
+            let now = Instant::now();
+            for (i, (deadline, job)) in off_thread_job_queue.iter().enumerate() {
+                let deadline_reached = deadline.is_none_or(|d| now >= d);
+                if deadline_reached && job.is_finished() {
+                    let (_, job) = off_thread_job_queue.swap_remove(i);
                     return Some(job);
                 }
             }
@@ -101,14 +109,19 @@ impl CliHostHooks {
 
 impl HostHooks for CliHostHooks {
     fn enqueue_generic_job(&self, job: Job) {
-        self.macrotask_queue.borrow_mut().push(job);
+        self.macrotask_queue.borrow_mut().push((None, job));
     }
 
     fn enqueue_promise_job(&self, job: Job) {
         self.promise_job_queue.borrow_mut().push_back(job);
     }
 
-    fn enqueue_timeout_job(&self, _timeout_job: Job, _milliseconds: u64) {}
+    fn enqueue_timeout_job(&self, timeout_job: Job, milliseconds: u64) {
+        let deadline = Instant::now() + Duration::from_millis(milliseconds);
+        self.macrotask_queue
+            .borrow_mut()
+            .push((Some(deadline), timeout_job));
+    }
 
     fn load_imported_module<'gc>(
         &self,

nova_lint/Cargo.toml

@@ -45,12 +45,14 @@ name = "spec_header_level"
 path = "ui/spec_header_level.rs"
 
 [dependencies]
-clippy_utils = { git = "https://github.com/rust-lang/rust-clippy", rev = "c936595d17413c1f08e162e117e504fb4ed126e4" }
-dylint_linting = { version = "5.0.0", features = ["constituent"] }
+# Must match the nightly toolchain pinned in .github/workflows/ci.yml: each
+# clippy_utils release only builds with its contemporary nightly.
+clippy_utils = "0.1.98"
+dylint_linting = { version = "6.0.1", features = ["constituent"] }
 regex = "1"
 
 [dev-dependencies]
-dylint_testing = "5.0.0"
+dylint_testing = "6.0.1"
 nova_vm = { path = "../nova_vm" }
 
 [package.metadata.rust-analyzer]

nova_lint/rust-toolchain

@@ -1,3 +1,3 @@
 [toolchain]
-channel = "nightly-2025-10-31"
+channel = "nightly-2026-05-28"
 components = ["llvm-tools-preview", "rustc-dev"]

nova_lint/src/utils.rs

@@ -51,7 +51,7 @@ pub fn match_def_paths(cx: &LateContext<'_>, did: DefId, syms: &[&[&str]]) -> bo
 
 pub fn is_trait_item(cx: &LateContext<'_>, hir_id: HirId) -> bool {
     if let Node::Item(item) = cx.tcx.parent_hir_node(hir_id) {
-        matches!(item.kind, ItemKind::Trait(..))
+        matches!(item.kind, ItemKind::Trait { .. })
     } else {
         false
     }