1 files changed, 142 insertions, 0 deletions
diff --git a/runtime/ops/signal.rs b/runtime/ops/signal.rs
new file mode 100644
index 000000000..be6bc0a35
--- /dev/null
+++ b/runtime/ops/signal.rs
@@ -0,0 +1,142 @@
+// Copyright 2018-2020 the Deno authors. All rights reserved. MIT license.
+
+use deno_core::error::AnyError;
+use deno_core::serde_json::Value;
+use deno_core::BufVec;
+use deno_core::OpState;
+use deno_core::ZeroCopyBuf;
+use std::cell::RefCell;
+use std::rc::Rc;
+
+#[cfg(unix)]
+use deno_core::error::bad_resource_id;
+#[cfg(unix)]
+use deno_core::futures::future::poll_fn;
+#[cfg(unix)]
+use deno_core::serde_json;
+#[cfg(unix)]
+use deno_core::serde_json::json;
+#[cfg(unix)]
+use serde::Deserialize;
+#[cfg(unix)]
+use std::task::Waker;
+#[cfg(unix)]
+use tokio::signal::unix::{signal, Signal, SignalKind};
+
+pub fn init(rt: &mut deno_core::JsRuntime) {
+  super::reg_json_sync(rt, "op_signal_bind", op_signal_bind);
+  super::reg_json_sync(rt, "op_signal_unbind", op_signal_unbind);
+  super::reg_json_async(rt, "op_signal_poll", op_signal_poll);
+}
+
+#[cfg(unix)]
+/// The resource for signal stream.
+/// The second element is the waker of polling future.
+pub struct SignalStreamResource(pub Signal, pub Option<Waker>);
+
+#[cfg(unix)]
+#[derive(Deserialize)]
+struct BindSignalArgs {
+  signo: i32,
+}
+
+#[cfg(unix)]
+#[derive(Deserialize)]
+struct SignalArgs {
+  rid: i32,
+}
+
+#[cfg(unix)]
+fn op_signal_bind(
+  state: &mut OpState,
+  args: Value,
+  _zero_copy: &mut [ZeroCopyBuf],
+) -> Result<Value, AnyError> {
+  super::check_unstable(state, "Deno.signal");
+  let args: BindSignalArgs = serde_json::from_value(args)?;
+  let rid = state.resource_table.add(
+    "signal",
+    Box::new(SignalStreamResource(
+      signal(SignalKind::from_raw(args.signo)).expect(""),
+      None,
+    )),
+  );
+  Ok(json!({
+    "rid": rid,
+  }))
+}
+
+#[cfg(unix)]
+async fn op_signal_poll(
+  state: Rc<RefCell<OpState>>,
+  args: Value,
+  _zero_copy: BufVec,
+) -> Result<Value, AnyError> {
+  super::check_unstable2(&state, "Deno.signal");
+  let args: SignalArgs = serde_json::from_value(args)?;
+  let rid = args.rid as u32;
+
+  let future = poll_fn(move |cx| {
+    let mut state = state.borrow_mut();
+    if let Some(mut signal) =
+      state.resource_table.get_mut::<SignalStreamResource>(rid)
+    {
+      signal.1 = Some(cx.waker().clone());
+      return signal.0.poll_recv(cx);
+    }
+    std::task::Poll::Ready(None)
+  });
+  let result = future.await;
+  Ok(json!({ "done": result.is_none() }))
+}
+
+#[cfg(unix)]
+pub fn op_signal_unbind(
+  state: &mut OpState,
+  args: Value,
+  _zero_copy: &mut [ZeroCopyBuf],
+) -> Result<Value, AnyError> {
+  super::check_unstable(state, "Deno.signal");
+  let args: SignalArgs = serde_json::from_value(args)?;
+  let rid = args.rid as u32;
+  let resource = state.resource_table.get_mut::<SignalStreamResource>(rid);
+  if let Some(signal) = resource {
+    if let Some(waker) = &signal.1 {
+      // Wakes up the pending poll if exists.
+      // This prevents the poll future from getting stuck forever.
+      waker.clone().wake();
+    }
+  }
+  state
+    .resource_table
+    .close(rid)
+    .ok_or_else(bad_resource_id)?;
+  Ok(json!({}))
+}
+
+#[cfg(not(unix))]
+pub fn op_signal_bind(
+  _state: &mut OpState,
+  _args: Value,
+  _zero_copy: &mut [ZeroCopyBuf],
+) -> Result<Value, AnyError> {
+  unimplemented!();
+}
+
+#[cfg(not(unix))]
+fn op_signal_unbind(
+  _state: &mut OpState,
+  _args: Value,
+  _zero_copy: &mut [ZeroCopyBuf],
+) -> Result<Value, AnyError> {
+  unimplemented!();
+}
+
+#[cfg(not(unix))]
+async fn op_signal_poll(
+  _state: Rc<RefCell<OpState>>,
+  _args: Value,
+  _zero_copy: BufVec,
+) -> Result<Value, AnyError> {
+  unimplemented!();
+}