fix: new signal handling (#30029)

Set up a new centralized signal handling path, which emulates the
default unless something is explicitly registered to prevent it.

Fixes: https://github.com/denoland/deno/issues/29590

---------

Co-authored-by: Bartek Iwańczuk <biwanczuk@gmail.com>

Cargo.lock

@@ -2366,6 +2366,7 @@ dependencies = [
  "deno_error",
  "deno_features",
  "deno_permissions",
+ "deno_signals",
  "deno_tls",
  "hickory-proto",
  "hickory-resolver",
@@ -2609,14 +2610,12 @@ dependencies = [
  "deno_error",
  "deno_path_util",
  "deno_permissions",
- "deno_telemetry",
+ "deno_signals",
  "libc",
  "netif",
  "ntapi",
  "once_cell",
  "serde",
- "signal-hook",
- "signal-hook-registry",
  "thiserror 2.0.12",
  "tokio",
  "winapi",
@@ -2842,6 +2841,14 @@ dependencies = [
  "url",
 ]
 
+[[package]]
+name = "deno_signals"
+version = "0.1.0"
+dependencies = [
+ "signal-hook",
+ "winapi",
+]
+
 [[package]]
 name = "deno_snapshots"
 version = "0.25.0"
@@ -2888,6 +2895,7 @@ dependencies = [
  "deno_core",
  "deno_error",
  "deno_net",
+ "deno_signals",
  "deno_tls",
  "http-body-util",
  "hyper 1.6.0",

Cargo.toml

@@ -25,6 +25,7 @@ members = [
   "ext/net",
   "ext/node",
   "ext/rt_helper",
+  "ext/signals",
   "ext/telemetry",
   "ext/url",
   "ext/web",
@@ -101,6 +102,7 @@ deno_net = { version = "0.202.0", path = "./ext/net" }
 deno_node = { version = "0.148.0", path = "./ext/node" }
 deno_os = { version = "0.27.0", path = "./ext/os" }
 deno_process = { version = "0.25.0", path = "./ext/process" }
+deno_signals = { version = "0.1.0", path = "./ext/signals" }
 deno_telemetry = { version = "0.32.0", path = "./ext/telemetry" }
 deno_tls = { version = "0.197.0", path = "./ext/tls" }
 deno_url = { version = "0.210.0", path = "./ext/url" }
@@ -242,6 +244,7 @@ serde-value = "0.7"
 serde_bytes = "0.11"
 serde_json = "1.0.85"
 serde_repr = "=0.1.19"
+signal-hook = "0.3"
 simd-json = "0.14.0"
 slab = "0.4"
 smallvec = "1.8"

ext/http/http_next.rs

@@ -30,6 +30,7 @@ use deno_core::serde_v8::from_v8;
 use deno_core::unsync::JoinHandle;
 use deno_core::unsync::spawn;
 use deno_core::v8;
+use deno_error::JsErrorClass;
 use deno_net::ops_tls::TlsStream;
 use deno_net::raw::NetworkStream;
 use deno_websocket::ws_create_server_stream;
@@ -1299,6 +1300,23 @@ pub async fn op_http_wait(
       }
     }
 
+    if let HttpNextError::Other(err) = &err {
+      if let Some(err) = err.as_any().downcast_ref::<std::io::Error>() {
+        if let Some(err) = err.get_ref() {
+          if let Some(err) =
+            err.downcast_ref::<deno_net::tunnel::quinn::ConnectionError>()
+          {
+            if matches!(
+              err,
+              deno_net::tunnel::quinn::ConnectionError::LocallyClosed
+            ) {
+              return Ok(null());
+            }
+          }
+        }
+      }
+    }
+
     return Err(err);
   }
 

ext/net/Cargo.toml

@@ -18,6 +18,7 @@ deno_core.workspace = true
 deno_error.workspace = true
 deno_features.workspace = true
 deno_permissions.workspace = true
+deno_signals.workspace = true
 deno_tls.workspace = true
 hickory-proto.workspace = true
 hickory-resolver.workspace = true

ext/net/tunnel.rs

@@ -21,6 +21,7 @@ use deno_tls::SocketUse;
 use deno_tls::TlsKeys;
 use deno_tls::create_client_config;
 use deno_tls::rustls::RootCertStore;
+pub use quinn;
 use quinn::ConnectionError;
 use quinn::crypto::rustls::QuicClientConfig;
 use tokio::io::AsyncRead;
@@ -61,7 +62,16 @@ static TUNNEL: OnceLock<crate::tunnel::TunnelListener> = OnceLock::new();
 
 pub fn set_tunnel(tunnel: crate::tunnel::TunnelListener) {
   if TUNNEL.set(tunnel).is_ok() {
-    setup_signal_handlers();
+    deno_signals::before_exit(before_exit);
+  }
+}
+
+fn before_exit() {
+  if let Some(tunnel) = get_tunnel() {
+    tunnel.connection.close(1u32.into(), b"");
+    // stay alive long enough to actually send the close frame, since
+    // we can't rely on the linux kernel to close this like with tcp.
+    deno_core::futures::executor::block_on(tunnel.endpoint.wait_idle());
   }
 }
 
@@ -69,57 +79,6 @@ pub fn get_tunnel() -> Option<&'static crate::tunnel::TunnelListener> {
   TUNNEL.get()
 }
 
-#[cfg(unix)]
-fn setup_signal_handlers() {
-  use tokio::signal::unix::SignalKind;
-
-  let signals_to_handle = [
-    SignalKind::hangup(),
-    SignalKind::interrupt(),
-    SignalKind::terminate(),
-  ];
-
-  for signal_kind in signals_to_handle {
-    tokio::spawn(async move {
-      let Ok(mut signal_fut) = tokio::signal::unix::signal(signal_kind) else {
-        return;
-      };
-
-      loop {
-        signal_fut.recv().await;
-        if let Some(tunnel) = get_tunnel() {
-          tunnel.connection.close(1u32.into(), b"");
-        }
-      }
-    });
-  }
-}
-
-#[cfg(windows)]
-fn setup_signal_handlers() {
-  macro_rules! handle_signal {
-    ($handler:expr) => {
-      tokio::spawn(async {
-        let Ok(mut signal_fut) = $handler() else {
-          return;
-        };
-        loop {
-          signal_fut.recv().await;
-          if let Some(tunnel) = get_tunnel() {
-            tunnel.connection.close(1u32.into(), b"");
-          }
-        }
-      });
-    };
-  }
-
-  handle_signal!(tokio::signal::windows::ctrl_break);
-  handle_signal!(tokio::signal::windows::ctrl_c);
-  handle_signal!(tokio::signal::windows::ctrl_close);
-  handle_signal!(tokio::signal::windows::ctrl_logoff);
-  handle_signal!(tokio::signal::windows::ctrl_shutdown);
-}
-
 /// Essentially a SocketAddr, except we prefer a human
 /// readable hostname to identify the remote endpoint.
 #[derive(Debug, Clone)]

ext/os/Cargo.toml

@@ -18,7 +18,7 @@ deno_core.workspace = true
 deno_error.workspace = true
 deno_path_util.workspace = true
 deno_permissions.workspace = true
-deno_telemetry.workspace = true
+deno_signals.workspace = true
 libc.workspace = true
 netif.workspace = true
 once_cell.workspace = true
@@ -29,7 +29,3 @@ tokio.workspace = true
 [target.'cfg(windows)'.dependencies]
 winapi = { workspace = true, features = ["commapi", "knownfolders", "mswsock", "objbase", "psapi", "shlobj", "sysinfoapi", "tlhelp32", "winbase", "winerror", "winuser", "winsock2"] }
 ntapi = "0.4.0"
-
-[target.'cfg(unix)'.dependencies]
-signal-hook = "0.3.17"
-signal-hook-registry = "1.4.2"

ext/os/lib.rs

@@ -42,7 +42,7 @@ impl ExitCode {
 }
 
 pub fn exit(code: i32) -> ! {
-  deno_telemetry::flush();
+  deno_signals::run_exit();
   #[allow(clippy::disallowed_methods)]
   std::process::exit(code);
 }
@@ -81,10 +81,6 @@ deno_core::extension!(
     if let Some(exit_code) = options.exit_code {
       state.put::<ExitCode>(exit_code);
     }
-    #[cfg(unix)]
-    {
-      state.put(ops::signal::SignalState::default());
-    }
   }
 );
 

ext/os/ops/signal.rs

@@ -1,35 +1,15 @@
 // Copyright 2018-2025 the Deno authors. MIT license.
 use std::borrow::Cow;
 use std::cell::RefCell;
-#[cfg(unix)]
-use std::collections::BTreeMap;
 use std::rc::Rc;
-#[cfg(unix)]
-use std::sync::Arc;
-#[cfg(unix)]
-use std::sync::atomic::AtomicBool;
 
 use deno_core::AsyncRefCell;
-use deno_core::CancelFuture;
-use deno_core::CancelHandle;
 use deno_core::OpState;
 use deno_core::RcRef;
 use deno_core::Resource;
 use deno_core::ResourceId;
 use deno_core::error::ResourceError;
 use deno_core::op2;
-#[cfg(unix)]
-use tokio::signal::unix::Signal;
-#[cfg(unix)]
-use tokio::signal::unix::SignalKind;
-#[cfg(unix)]
-use tokio::signal::unix::signal;
-#[cfg(windows)]
-use tokio::signal::windows::CtrlBreak;
-#[cfg(windows)]
-use tokio::signal::windows::CtrlC;
-#[cfg(windows)]
-use tokio::signal::windows::CtrlClose;
 
 #[derive(Debug, thiserror::Error, deno_error::JsError)]
 pub enum SignalError {
@@ -47,117 +27,22 @@ pub enum SignalError {
   Io(#[from] std::io::Error),
 }
 
-#[cfg(unix)]
-#[derive(Default)]
-pub struct SignalState {
-  enable_default_handlers: BTreeMap<libc::c_int, Arc<AtomicBool>>,
-}
-
-#[cfg(unix)]
-impl SignalState {
-  /// Disable the default signal handler for the given signal.
-  ///
-  /// Returns the shared flag to enable the default handler later, and whether a default handler already existed.
-  fn disable_default_handler(
-    &mut self,
-    signo: libc::c_int,
-  ) -> (Arc<AtomicBool>, bool) {
-    use std::collections::btree_map::Entry;
-
-    match self.enable_default_handlers.entry(signo) {
-      Entry::Occupied(entry) => {
-        let enable = entry.get();
-        enable.store(false, std::sync::atomic::Ordering::Release);
-        (enable.clone(), true)
-      }
-      Entry::Vacant(entry) => {
-        let enable = Arc::new(AtomicBool::new(false));
-        entry.insert(enable.clone());
-        (enable, false)
-      }
-    }
-  }
-}
-
-#[cfg(unix)]
-/// The resource for signal stream.
-/// The second element is the waker of polling future.
 struct SignalStreamResource {
-  signal: AsyncRefCell<Signal>,
+  signo: i32,
-  enable_default_handler: Arc<AtomicBool>,
+  id: u32,
-  cancel: CancelHandle,
+  rx: AsyncRefCell<tokio::sync::watch::Receiver<()>>,
 }
 
-#[cfg(unix)]
 impl Resource for SignalStreamResource {
   fn name(&self) -> Cow<str> {
     "signal".into()
   }
 
   fn close(self: Rc<Self>) {
-    self.cancel.cancel();
+    deno_signals::unregister(self.signo, self.id);
   }
 }
 
-// TODO: CtrlClose could be mapped to SIGHUP but that needs a
-// tokio::windows::signal::CtrlClose type, or something from a different crate
-#[cfg(windows)]
-enum WindowsSignal {
-  Sigint(CtrlC),
-  Sigbreak(CtrlBreak),
-  Sighup(CtrlClose),
-}
-
-#[cfg(windows)]
-impl From<CtrlC> for WindowsSignal {
-  fn from(ctrl_c: CtrlC) -> Self {
-    Self::Sigint(ctrl_c)
-  }
-}
-
-#[cfg(windows)]
-impl From<CtrlBreak> for WindowsSignal {
-  fn from(ctrl_break: CtrlBreak) -> Self {
-    Self::Sigbreak(ctrl_break)
-  }
-}
-
-#[cfg(windows)]
-impl From<CtrlClose> for WindowsSignal {
-  fn from(ctrl_close: CtrlClose) -> Self {
-    Self::Sighup(ctrl_close)
-  }
-}
-
-#[cfg(windows)]
-impl WindowsSignal {
-  pub async fn recv(&mut self) -> Option<()> {
-    match self {
-      Self::Sigint(ctrl_c) => ctrl_c.recv().await,
-      Self::Sigbreak(ctrl_break) => ctrl_break.recv().await,
-      Self::Sighup(ctrl_close) => ctrl_close.recv().await,
-    }
-  }
-}
-
-#[cfg(windows)]
-struct SignalStreamResource {
-  signal: AsyncRefCell<WindowsSignal>,
-  cancel: CancelHandle,
-}
-
-#[cfg(windows)]
-impl Resource for SignalStreamResource {
-  fn name(&self) -> Cow<str> {
-    "signal".into()
-  }
-
-  fn close(self: Rc<Self>) {
-    self.cancel.cancel();
-  }
-}
-
-#[cfg(unix)]
 #[op2(fast)]
 #[smi]
 pub fn op_signal_bind(
@@ -165,60 +50,25 @@ pub fn op_signal_bind(
   #[string] sig: &str,
 ) -> Result<ResourceId, SignalError> {
   let signo = crate::signal::signal_str_to_int(sig)?;
-  if signal_hook_registry::FORBIDDEN.contains(&signo) {
+  if deno_signals::is_forbidden(signo) {
     return Err(SignalError::SignalNotAllowed(sig.to_string()));
   }
 
-  let signal = AsyncRefCell::new(signal(SignalKind::from_raw(signo))?);
+  let (tx, rx) = tokio::sync::watch::channel(());
-
+  let id = deno_signals::register(
-  let (enable_default_handler, has_default_handler) = state
-    .borrow_mut::<SignalState>()
-    .disable_default_handler(signo);
-
-  let resource = SignalStreamResource {
-    signal,
-    cancel: Default::default(),
-    enable_default_handler: enable_default_handler.clone(),
-  };
-  let rid = state.resource_table.add(resource);
-
-  if !has_default_handler {
-    // restore default signal handler when the signal is unbound
-    // this can error if the signal is not supported, if so let's just leave it as is
-    let _ = signal_hook::flag::register_conditional_default(
     signo,
-      enable_default_handler,
+    true,
-    );
+    Box::new(move || {
-  }
+      let _ = tx.send(());
-
-  Ok(rid)
-}
-
-#[cfg(windows)]
-#[op2(fast)]
-#[smi]
-pub fn op_signal_bind(
-  state: &mut OpState,
-  #[string] sig: &str,
-) -> Result<ResourceId, SignalError> {
-  use tokio::signal::windows::ctrl_break;
-  use tokio::signal::windows::ctrl_c;
-  use tokio::signal::windows::ctrl_close;
-
-  let resource = SignalStreamResource {
-    signal: AsyncRefCell::new(match sig {
-      "SIGHUP" => ctrl_close()?.into(),
-      "SIGINT" => ctrl_c()?.into(),
-      "SIGBREAK" => ctrl_break()?.into(),
-      _ => {
-        return Err(
-          crate::signal::InvalidSignalStrError(sig.to_string()).into(),
-        );
-      }
     }),
-    cancel: Default::default(),
+  );
-  };
+
-  let rid = state.resource_table.add(resource);
+  let rid = state.resource_table.add(SignalStreamResource {
+    signo,
+    id,
+    rx: AsyncRefCell::new(rx),
+  });
+
   Ok(rid)
 }
 
@@ -232,13 +82,9 @@ pub async fn op_signal_poll(
     .resource_table
     .get::<SignalStreamResource>(rid)?;
 
-  let cancel = RcRef::map(&resource, |r| &r.cancel);
+  let mut rx = RcRef::map(&resource, |r| &r.rx).borrow_mut().await;
-  let mut signal = RcRef::map(&resource, |r| &r.signal).borrow_mut().await;
 
-  match signal.recv().or_cancel(cancel).await {
+  Ok(rx.changed().await.is_err())
-    Ok(result) => Ok(result.is_none()),
-    Err(_) => Ok(true),
-  }
 }
 
 #[op2(fast)]
@@ -247,14 +93,6 @@ pub fn op_signal_unbind(
   #[smi] rid: ResourceId,
 ) -> Result<(), ResourceError> {
   let resource = state.resource_table.take::<SignalStreamResource>(rid)?;
-
-  #[cfg(unix)]
-  {
-    resource
-      .enable_default_handler
-      .store(true, std::sync::atomic::Ordering::Release);
-  }
-
   resource.close();
   Ok(())
 }

ext/signals/Cargo.toml

@@ -0,0 +1,18 @@
+# Copyright 2018-2025 the Deno authors. MIT license.
+
+[package]
+name = "deno_signals"
+version = "0.1.0"
+authors.workspace = true
+edition.workspace = true
+license.workspace = true
+readme = "README.md"
+repository.workspace = true
+description = "Signals for Deno"
+
+[lib]
+path = "lib.rs"
+
+[dependencies]
+signal-hook.workspace = true
+winapi.workspace = true

ext/signals/README.md

@@ -0,0 +1 @@
+Signal handling for Deno

ext/signals/lib.rs

@@ -0,0 +1,164 @@
+// Copyright 2018-2025 the Deno authors. MIT license.
+
+use std::collections::HashMap;
+use std::sync::Mutex;
+use std::sync::OnceLock;
+use std::sync::atomic::AtomicU32;
+use std::sync::atomic::Ordering;
+
+use signal_hook::consts::*;
+
+#[cfg(windows)]
+static SIGHUP: i32 = 1;
+
+static COUNTER: AtomicU32 = AtomicU32::new(0);
+
+type Handler = Box<dyn Fn() + Send>;
+type Handlers = HashMap<i32, Vec<(u32, bool, Handler)>>;
+static HANDLERS: OnceLock<(Handle, Mutex<Handlers>)> = OnceLock::new();
+
+#[cfg(unix)]
+struct Handle(signal_hook::iterator::Handle);
+
+#[cfg(windows)]
+struct Handle;
+
+fn handle_signal(signal: i32) -> bool {
+  let Some((_, handlers)) = HANDLERS.get() else {
+    return false;
+  };
+  let handlers = handlers.lock().unwrap();
+  let Some(handlers) = handlers.get(&signal) else {
+    return false;
+  };
+
+  let mut handled = false;
+
+  for (_, prevent_default, f) in handlers {
+    if *prevent_default {
+      handled = true;
+    }
+
+    f();
+  }
+
+  handled
+}
+
+#[cfg(unix)]
+fn init() -> Handle {
+  use signal_hook::iterator::Signals;
+
+  let mut signals = Signals::new::<[i32; 0], i32>([]).unwrap();
+  let handle = signals.handle();
+
+  std::thread::spawn(move || {
+    for signal in signals.forever() {
+      let handled = handle_signal(signal);
+      if !handled {
+        signal_hook::low_level::emulate_default_handler(signal).unwrap();
+      }
+    }
+  });
+
+  Handle(handle)
+}
+
+#[cfg(windows)]
+fn init() -> Handle {
+  unsafe extern "system" fn handle(ctrl_type: u32) -> i32 {
+    let signal = match ctrl_type {
+      0 => SIGINT,
+      1 => SIGBREAK,
+      2 => SIGHUP,
+      5 => SIGTERM,
+      6 => SIGTERM,
+      _ => return 0,
+    };
+    let handled = handle_signal(signal);
+    handled as _
+  }
+
+  // SAFETY: Registering handler
+  unsafe {
+    winapi::um::consoleapi::SetConsoleCtrlHandler(Some(handle), 1);
+  }
+
+  Handle
+}
+
+pub fn register(
+  signal: i32,
+  prevent_default: bool,
+  f: Box<dyn Fn() + Send>,
+) -> u32 {
+  let (handle, handlers) = HANDLERS.get_or_init(|| {
+    let handle = init();
+
+    let handlers = Mutex::new(HashMap::new());
+
+    (handle, handlers)
+  });
+
+  let id = COUNTER.fetch_add(1, Ordering::Relaxed);
+  let mut handlers = handlers.lock().unwrap();
+  match handlers.entry(signal) {
+    std::collections::hash_map::Entry::Occupied(mut v) => {
+      v.get_mut().push((id, prevent_default, f))
+    }
+    std::collections::hash_map::Entry::Vacant(v) => {
+      v.insert(vec![(id, prevent_default, f)]);
+
+      #[cfg(unix)]
+      {
+        handle.0.add_signal(signal).unwrap();
+      }
+      #[cfg(windows)]
+      {
+        let _ = handle;
+      }
+    }
+  }
+
+  id
+}
+
+pub fn unregister(signal: i32, id: u32) {
+  let Some((_, handlers)) = HANDLERS.get() else {
+    return;
+  };
+  let mut handlers = handlers.lock().unwrap();
+  let Some(handlers) = handlers.get_mut(&signal) else {
+    return;
+  };
+  let Some(index) = handlers.iter().position(|v| v.0 == id) else {
+    return;
+  };
+  let _ = handlers.swap_remove(index);
+}
+
+static BEFORE_EXIT: OnceLock<Mutex<Vec<Handler>>> = OnceLock::new();
+
+pub fn before_exit(f: fn()) {
+  register(SIGHUP, false, Box::new(f));
+  register(SIGTERM, false, Box::new(f));
+  register(SIGINT, false, Box::new(f));
+  BEFORE_EXIT
+    .get_or_init(|| Mutex::new(vec![]))
+    .lock()
+    .unwrap()
+    .push(Box::new(f));
+}
+
+pub fn run_exit() {
+  if let Some(fns) = BEFORE_EXIT.get() {
+    let fns = fns.lock().unwrap();
+    for f in fns.iter() {
+      f();
+    }
+  }
+}
+
+pub fn is_forbidden(signo: i32) -> bool {
+  FORBIDDEN.contains(&signo)
+}

ext/telemetry/Cargo.toml

@@ -18,6 +18,7 @@ async-trait.workspace = true
 deno_core.workspace = true
 deno_error.workspace = true
 deno_net.workspace = true
+deno_signals.workspace = true
 deno_tls.workspace = true
 http-body-util.workspace = true
 hyper.workspace = true

ext/telemetry/lib.rs

@@ -927,6 +927,8 @@ pub fn init(
     })
     .map_err(|_| deno_core::anyhow::anyhow!("failed to set otel globals"))?;
 
+  deno_signals::before_exit(flush);
+
   Ok(())
 }