Function spawn

src/master/spawn.ts:143–166

(
  worker: WorkerType,
  options?: { timeout?: number }
)

 * @param [options.timeout] Init message timeout. Default: 10000 or set by environment variable.
 */
export async function spawn<Exposed extends WorkerFunction | WorkerModule<any> = ArbitraryWorkerInterface>(
  worker: WorkerType,
  options?: { timeout?: number }
): Promise<ExposedToThreadType<Exposed>> {
  debugSpawn("Initializing new thread")

  const timeout = options && options.timeout ? options.timeout : initMessageTimeout
  const initMessage = await withTimeout(receiveInitMessage(worker), timeout, `Timeout: Did not receive an init message from worker after ${timeout}ms. Make sure the worker calls expose().`)
  const exposed = initMessage.exposed

  const { termination, terminate } = createTerminator(worker)
  const events = createEventObservable(worker, termination)

  if (exposed.type === "function") {
    const proxy = createProxyFunction(worker)
    return setPrivateThreadProps(proxy, worker, events, terminate) as ExposedToThreadType<Exposed>
  } else if (exposed.type === "module") {
    const proxy = createProxyModule(worker, exposed.methods)
    return setPrivateThreadProps(proxy, worker, events, terminate) as ExposedToThreadType<Exposed>
  } else {
    const type = (exposed as WorkerInitMessage["exposed"]).type
    throw Error(`Worker init message states unexpected type of expose(): ${type}`)
  }
}