fix(ext/node): allow automatic worker_thread termination (#22647)

Co-authored-by: Matt Mastracci <matthew@mastracci.com>

2 files changed, 17 insertions, 11 deletions

diff --git a/runtime/js/11_workers.js b/runtime/js/11_workers.js
index 15bbad101..5d24df93d 100644
--- a/runtime/js/11_workers.js
+++ b/runtime/js/11_workers.js
@@ -46,6 +46,7 @@ function createWorker(
   permissions,
   name,
   workerType,
+  closeOnIdle,
 ) {
   return op_create_worker({
     hasSourceCode,
@@ -54,6 +55,7 @@ function createWorker(
     sourceCode,
     specifier,
     workerType,
+    closeOnIdle,
   });
 }
 
@@ -75,14 +77,6 @@ function hostRecvMessage(id) {
 
 const privateWorkerRef = Symbol();
 
-function refWorker(worker) {
-  worker[privateWorkerRef](true);
-}
-
-function unrefWorker(worker) {
-  worker[privateWorkerRef](false);
-}
-
 class Worker extends EventTarget {
   #id = 0;
   #name = "";
@@ -134,8 +128,9 @@ class Worker extends EventTarget {
       hasSourceCode,
       sourceCode,
       deno?.permissions,
-      name,
+      this.#name,
       workerType,
+      false,
     );
     this.#id = id;
     this.#pollControl();
@@ -325,4 +320,4 @@ webidl.converters["WorkerType"] = webidl.createEnumConverter("WorkerType", [
   "module",
 ]);
 
-export { refWorker, unrefWorker, Worker };
+export { Worker };
diff --git a/runtime/js/99_main.js b/runtime/js/99_main.js
index 27ba488e7..585128ba8 100644
--- a/runtime/js/99_main.js
+++ b/runtime/js/99_main.js
@@ -279,6 +279,7 @@ function postMessage(message, transferOrOptions = {}) {
 
 let isClosing = false;
 let globalDispatchEvent;
+let closeOnIdle;
 
 async function pollForMessages() {
   if (!globalDispatchEvent) {
@@ -288,7 +289,14 @@ async function pollForMessages() {
     );
   }
   while (!isClosing) {
-    const data = await op_worker_recv_message();
+    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;
     if (data === null) break;
     const v = messagePort.deserializeJsMessageData(data);
     const message = v[0];
@@ -803,6 +811,8 @@ function bootstrapWorkerRuntime(
     6: argv0,
     7: shouldDisableDeprecatedApiWarning,
     8: shouldUseVerboseDeprecatedApiWarning,
+    9: _future,
+    10: closeOnIdle_,
   } = runtimeOptions;
 
   deprecatedApiWarningDisabled = shouldDisableDeprecatedApiWarning;
@@ -864,6 +874,7 @@ function bootstrapWorkerRuntime(
 
   location.setLocationHref(location_);
 
+  closeOnIdle = closeOnIdle_;
   globalThis.pollForMessages = pollForMessages;
 
   // TODO(bartlomieju): deprecate --unstable