1 files changed, 248 insertions, 0 deletions
diff --git a/ext/node/polyfills/worker_threads.ts b/ext/node/polyfills/worker_threads.ts
new file mode 100644
index 000000000..7bca5fc4e
--- /dev/null
+++ b/ext/node/polyfills/worker_threads.ts
@@ -0,0 +1,248 @@
+// Copyright 2018-2023 the Deno authors. All rights reserved. MIT license.
+// Copyright Joyent and Node contributors. All rights reserved. MIT license.
+
+import { resolve, toFileUrl } from "internal:deno_node/polyfills/path.ts";
+import { notImplemented } from "internal:deno_node/polyfills/_utils.ts";
+import { EventEmitter } from "internal:deno_node/polyfills/events.ts";
+
+const environmentData = new Map();
+let threads = 0;
+
+export interface WorkerOptions {
+  // only for typings
+  argv?: unknown[];
+  env?: Record<string, unknown>;
+  execArgv?: string[];
+  stdin?: boolean;
+  stdout?: boolean;
+  stderr?: boolean;
+  trackUnmanagedFds?: boolean;
+  resourceLimits?: {
+    maxYoungGenerationSizeMb?: number;
+    maxOldGenerationSizeMb?: number;
+    codeRangeSizeMb?: number;
+    stackSizeMb?: number;
+  };
+
+  eval?: boolean;
+  transferList?: Transferable[];
+  workerData?: unknown;
+}
+
+const kHandle = Symbol("kHandle");
+const PRIVATE_WORKER_THREAD_NAME = "$DENO_STD_NODE_WORKER_THREAD";
+class _Worker extends EventEmitter {
+  readonly threadId: number;
+  readonly resourceLimits: Required<
+    NonNullable<WorkerOptions["resourceLimits"]>
+  > = {
+    maxYoungGenerationSizeMb: -1,
+    maxOldGenerationSizeMb: -1,
+    codeRangeSizeMb: -1,
+    stackSizeMb: 4,
+  };
+  private readonly [kHandle]: Worker;
+
+  postMessage: Worker["postMessage"];
+
+  constructor(specifier: URL | string, options?: WorkerOptions) {
+    notImplemented("Worker");
+    super();
+    if (options?.eval === true) {
+      specifier = `data:text/javascript,${specifier}`;
+    } else if (typeof specifier === "string") {
+      // @ts-ignore This API is temporarily disabled
+      specifier = toFileUrl(resolve(specifier));
+    }
+    const handle = this[kHandle] = new Worker(
+      specifier,
+      {
+        name: PRIVATE_WORKER_THREAD_NAME,
+        type: "module",
+      } as globalThis.WorkerOptions, // bypass unstable type error
+    );
+    handle.addEventListener(
+      "error",
+      (event) => this.emit("error", event.error || event.message),
+    );
+    handle.addEventListener(
+      "messageerror",
+      (event) => this.emit("messageerror", event.data),
+    );
+    handle.addEventListener(
+      "message",
+      (event) => this.emit("message", event.data),
+    );
+    handle.postMessage({
+      environmentData,
+      threadId: (this.threadId = ++threads),
+      workerData: options?.workerData,
+    }, options?.transferList || []);
+    this.postMessage = handle.postMessage.bind(handle);
+    this.emit("online");
+  }
+
+  terminate() {
+    this[kHandle].terminate();
+    this.emit("exit", 0);
+  }
+
+  readonly getHeapSnapshot = () =>
+    notImplemented("Worker.prototype.getHeapSnapshot");
+  // fake performance
+  readonly performance = globalThis.performance;
+}
+
+export const isMainThread =
+  // deno-lint-ignore no-explicit-any
+  (globalThis as any).name !== PRIVATE_WORKER_THREAD_NAME;
+
+// fake resourceLimits
+export const resourceLimits = isMainThread ? {} : {
+  maxYoungGenerationSizeMb: 48,
+  maxOldGenerationSizeMb: 2048,
+  codeRangeSizeMb: 0,
+  stackSizeMb: 4,
+};
+
+const threadId = 0;
+const workerData: unknown = null;
+
+// Like https://github.com/nodejs/node/blob/48655e17e1d84ba5021d7a94b4b88823f7c9c6cf/lib/internal/event_target.js#L611
+interface NodeEventTarget extends
+  Pick<
+    EventEmitter,
+    "eventNames" | "listenerCount" | "emit" | "removeAllListeners"
+  > {
+  setMaxListeners(n: number): void;
+  getMaxListeners(): number;
+  // deno-lint-ignore no-explicit-any
+  off(eventName: string, listener: (...args: any[]) => void): NodeEventTarget;
+  // deno-lint-ignore no-explicit-any
+  on(eventName: string, listener: (...args: any[]) => void): NodeEventTarget;
+  // deno-lint-ignore no-explicit-any
+  once(eventName: string, listener: (...args: any[]) => void): NodeEventTarget;
+  addListener: NodeEventTarget["on"];
+  removeListener: NodeEventTarget["off"];
+}
+
+type ParentPort = typeof self & NodeEventTarget;
+
+// deno-lint-ignore no-explicit-any
+const parentPort: ParentPort = null as any;
+
+/*
+if (!isMainThread) {
+  // deno-lint-ignore no-explicit-any
+  delete (globalThis as any).name;
+  // deno-lint-ignore no-explicit-any
+  const listeners = new WeakMap<(...args: any[]) => void, (ev: any) => any>();
+
+  parentPort = self as ParentPort;
+  parentPort.off = parentPort.removeListener = function (
+    this: ParentPort,
+    name,
+    listener,
+  ) {
+    this.removeEventListener(name, listeners.get(listener)!);
+    listeners.delete(listener);
+    return this;
+  };
+  parentPort.on = parentPort.addListener = function (
+    this: ParentPort,
+    name,
+    listener,
+  ) {
+    // deno-lint-ignore no-explicit-any
+    const _listener = (ev: any) => listener(ev.data);
+    listeners.set(listener, _listener);
+    this.addEventListener(name, _listener);
+    return this;
+  };
+  parentPort.once = function (this: ParentPort, name, listener) {
+    // deno-lint-ignore no-explicit-any
+    const _listener = (ev: any) => listener(ev.data);
+    listeners.set(listener, _listener);
+    this.addEventListener(name, _listener);
+    return this;
+  };
+
+  // mocks
+  parentPort.setMaxListeners = () => {};
+  parentPort.getMaxListeners = () => Infinity;
+  parentPort.eventNames = () => [""];
+  parentPort.listenerCount = () => 0;
+
+  parentPort.emit = () => notImplemented("parentPort.emit");
+  parentPort.removeAllListeners = () =>
+    notImplemented("parentPort.removeAllListeners");
+
+  // Receive startup message
+  [{ threadId, workerData, environmentData }] = await once(
+    parentPort,
+    "message",
+  );
+
+  // alias
+  parentPort.addEventListener("offline", () => {
+    parentPort.emit("close");
+  });
+}
+*/
+
+export function getEnvironmentData(key: unknown) {
+  notImplemented("getEnvironmentData");
+  return environmentData.get(key);
+}
+
+export function setEnvironmentData(key: unknown, value?: unknown) {
+  notImplemented("setEnvironmentData");
+  if (value === undefined) {
+    environmentData.delete(key);
+  } else {
+    environmentData.set(key, value);
+  }
+}
+
+// deno-lint-ignore no-explicit-any
+const _MessagePort: typeof MessagePort = (globalThis as any).MessagePort;
+const _MessageChannel: typeof MessageChannel =
+  // deno-lint-ignore no-explicit-any
+  (globalThis as any).MessageChannel;
+export const BroadcastChannel = globalThis.BroadcastChannel;
+export const SHARE_ENV = Symbol.for("nodejs.worker_threads.SHARE_ENV");
+export function markAsUntransferable() {
+  notImplemented("markAsUntransferable");
+}
+export function moveMessagePortToContext() {
+  notImplemented("moveMessagePortToContext");
+}
+export function receiveMessageOnPort() {
+  notImplemented("receiveMessageOnPort");
+}
+export {
+  _MessageChannel as MessageChannel,
+  _MessagePort as MessagePort,
+  _Worker as Worker,
+  parentPort,
+  threadId,
+  workerData,
+};
+
+export default {
+  markAsUntransferable,
+  moveMessagePortToContext,
+  receiveMessageOnPort,
+  MessagePort: _MessagePort,
+  MessageChannel: _MessageChannel,
+  BroadcastChannel,
+  Worker: _Worker,
+  getEnvironmentData,
+  setEnvironmentData,
+  SHARE_ENV,
+  threadId,
+  workerData,
+  resourceLimits,
+  parentPort,
+  isMainThread,
+};