1 files changed, 6 insertions, 11 deletions
diff --git a/runtime/js/99_main.js b/runtime/js/99_main.js
index 62e7278ff..e97eed9ff 100644
--- a/runtime/js/99_main.js
+++ b/runtime/js/99_main.js
@@ -279,7 +279,10 @@ function postMessage(message, transferOrOptions = {}) {
 
 let isClosing = false;
 let globalDispatchEvent;
-let closeOnIdle;
+
+function hasMessageEventListener() {
+  return event.listenerCount(globalThis, "message") > 0;
+}
 
 async function pollForMessages() {
   if (!globalDispatchEvent) {
@@ -289,14 +292,7 @@ async function pollForMessages() {
     );
   }
   while (!isClosing) {
-    const op = op_worker_recv_message();
-    // In a Node.js worker, unref() the op promise to prevent it from
-    // keeping the event loop alive. This avoids the need to explicitly
-    // call self.close() or worker.terminate().
-    if (closeOnIdle) {
-      core.unrefOpPromise(op);
-    }
-    const data = await op;
+    const data = await op_worker_recv_message();
     if (data === null) break;
     const v = messagePort.deserializeJsMessageData(data);
     const message = v[0];
@@ -813,7 +809,6 @@ function bootstrapWorkerRuntime(
     7: shouldDisableDeprecatedApiWarning,
     8: shouldUseVerboseDeprecatedApiWarning,
     9: _future,
-    10: closeOnIdle_,
   } = runtimeOptions;
 
   deprecatedApiWarningDisabled = shouldDisableDeprecatedApiWarning;
@@ -875,8 +870,8 @@ function bootstrapWorkerRuntime(
 
   location.setLocationHref(location_);
 
-  closeOnIdle = closeOnIdle_;
   globalThis.pollForMessages = pollForMessages;
+  globalThis.hasMessageEventListener = hasMessageEventListener;
 
   // TODO(bartlomieju): deprecate --unstable
   if (unstableFlag) {