fix(ext/node): worker_threads.receiveMessageOnPort doesn't panic (#23406)

Follow up to https://github.com/denoland/deno/pull/23386.
Instead of using async `recv()` method, it was replaced
with a poll based function that doesn't hold onto
RefCell borrow across await point.

Fixes https://github.com/denoland/deno/issues/23362

ext/web/message_port.rs

@@ -15,6 +15,7 @@ use deno_core::OpState;
 use deno_core::RcRef;
 use deno_core::Resource;
 use deno_core::ResourceId;
+use futures::future::poll_fn;
 use serde::Deserialize;
 use serde::Serialize;
 use tokio::sync::mpsc::error::TryRecvError;
@@ -52,16 +53,19 @@ impl MessagePort {
     Ok(())
   }
 
-  #[allow(clippy::await_holding_refcell_ref)] // TODO(ry) remove!
   pub async fn recv(
     &self,
     state: Rc<RefCell<OpState>>,
   ) -> Result<Option<JsMessageData>, AnyError> {
-    let mut rx = self
+    let rx = &self.rx;
-      .rx
+
-      .try_borrow_mut()
+    let maybe_data = poll_fn(|cx| {
-      .map_err(|_| type_error("Port receiver is already borrowed"))?;
+      let mut rx = rx.borrow_mut();
-    if let Some((data, transferables)) = rx.recv().await {
+      rx.poll_recv(cx)
+    })
+    .await;
+
+    if let Some((data, transferables)) = maybe_data {
       let js_transferables =
         serialize_transferables(&mut state.borrow_mut(), transferables);
       return Ok(Some(JsMessageData {

tests/unit_node/worker_threads_test.ts

@@ -418,21 +418,45 @@ Deno.test({
 // Regression test for https://github.com/denoland/deno/issues/23362
 Deno.test("[node/worker_threads] receiveMessageOnPort works if there's pending read", function () {
   const { port1, port2 } = new workerThreads.MessageChannel();
+  const { port1: port3, port2: port4 } = new workerThreads.MessageChannel();
+  const { port1: port5, port2: port6 } = new workerThreads.MessageChannel();
 
   const message1 = { hello: "world" };
   const message2 = { foo: "bar" };
 
   assertEquals(workerThreads.receiveMessageOnPort(port2), undefined);
   port2.start();
+  port4.start();
+  port6.start();
 
   port1.postMessage(message1);
   port1.postMessage(message2);
+  port3.postMessage(message1);
+  port3.postMessage(message2);
+  port5.postMessage(message1);
+  port5.postMessage(message2);
   assertEquals(workerThreads.receiveMessageOnPort(port2), {
     message: message1,
   });
   assertEquals(workerThreads.receiveMessageOnPort(port2), {
     message: message2,
   });
+  assertEquals(workerThreads.receiveMessageOnPort(port4), {
+    message: message1,
+  });
+  assertEquals(workerThreads.receiveMessageOnPort(port4), {
+    message: message2,
+  });
+  assertEquals(workerThreads.receiveMessageOnPort(port6), {
+    message: message1,
+  });
+  assertEquals(workerThreads.receiveMessageOnPort(port6), {
+    message: message2,
+  });
   port1.close();
   port2.close();
+  port3.close();
+  port4.close();
+  port5.close();
+  port6.close();
 });