feat: broadcast message to all workers

src/common.ts

@@ -1,6 +1,7 @@
 import type { MessagePort } from 'worker_threads'
 
 export interface StartupMessage {
+  tinypoolStartupMessage: true
   filename: string | null
   name: string
   port: MessagePort

src/index.ts

@@ -3,6 +3,7 @@ import {
   MessageChannel,
   MessagePort,
   receiveMessageOnPort,
+  parentPort,
 } from 'worker_threads'
 import { once } from 'events'
 import EventEmitterAsyncResource from './EventEmitterAsyncResource'
@@ -688,6 +689,7 @@ class ThreadPool {
     }
 
     const message: StartupMessage = {
+      tinypoolStartupMessage: true,
       filename: this.options.filename,
       name: this.options.name,
       port: port2,
@@ -1024,6 +1026,12 @@ class Tinypool extends EventEmitterAsyncResource {
     return this.#pool.runTask(task, { transferList, filename, name, signal })
   }
 
+  broadcastMessage(message: any) {
+    for (const workerInfo of this.#pool.workers) {
+      workerInfo.worker.postMessage(message)
+    }
+  }
+
   destroy() {
     return this.#pool.destroy()
   }
@@ -1102,6 +1110,14 @@ class Tinypool extends EventEmitterAsyncResource {
   }
 }
 
+export function onBroadcastedMessage(handler: (message: any) => void) {
+  if (parentPort) {
+    parentPort.on('message', handler)
+  } else {
+    throw new Error('onBroadcastedMessage can only be used in worker threads')
+  }
+}
+
 const _workerId = process.__tinypool_state__?.workerId
 
 export * from './common'

src/worker.ts

@@ -101,6 +101,7 @@ async function getHandler(
 parentPort!.on('message', (message: StartupMessage) => {
   useAtomics =
     process.env.PISCINA_DISABLE_ATOMICS === '1' ? false : message.useAtomics
+  if (!message?.tinypoolStartupMessage) return
   const { port, sharedBuffer, filename, name } = message
   ;(async function () {
     if (filename !== null) {