Wait for background workers before finish notices and cancel tools on shutdown

host/src/harness/input.rs

@@ -24,6 +24,7 @@ pub enum Input {
         reply: mpsc::UnboundedSender<Value>,
     },
     Stop,
+    Shutdown,
 }
 
 pub type Sender = mpsc::UnboundedSender<Input>;
@@ -78,7 +79,8 @@ pub(super) fn console(sender: Sender) {
     });
 }
 
-pub(super) fn stop_signal(
+/// Register SIGTERM and SIGINT before the harness starts.
+pub fn stop_signal(
     sender: Sender,
 ) -> std::io::Result<impl std::future::Future<Output = ()> + Send> {
     // Register before V8 starts, so a stop cannot arrive before the listener.
@@ -89,6 +91,6 @@ pub(super) fn stop_signal(
             _ = interrupt.recv() => {}
             _ = terminate.recv() => {}
         }
-        let _ = sender.send(Input::Stop);
+        let _ = sender.send(Input::Shutdown);
     })
 }