// Partial Copyright Jerome Benoit. 2021-2023. All Rights Reserved.
-import { Worker } from 'node:worker_threads';
+import { EventEmitter } from 'node:events';
+import { SHARE_ENV, Worker } from 'node:worker_threads';
import { WorkerAbstract } from './WorkerAbstract';
-import { WorkerConstants } from './WorkerConstants';
+import { DEFAULT_POOL_OPTIONS, EMPTY_FUNCTION, workerSetVersion } from './WorkerConstants';
import {
- type MessageHandler,
+ type SetInfo,
type WorkerData,
+ type WorkerMessage,
WorkerMessageEvents,
type WorkerOptions,
type WorkerSetElement,
+ WorkerSetEvents,
} from './WorkerTypes';
-import { WorkerUtils } from './WorkerUtils';
+import { sleep } from './WorkerUtils';
export class WorkerSet extends WorkerAbstract<WorkerData> {
+ public readonly emitter!: EventEmitter;
private readonly workerSet: Set<WorkerSetElement>;
+ private workerStartup: boolean;
/**
- * Create a new `WorkerSet`.
+ * Creates a new `WorkerSet`.
*
* @param workerScript -
* @param workerOptions -
*/
- constructor(workerScript: string, workerOptions?: WorkerOptions) {
+ constructor(workerScript: string, workerOptions: WorkerOptions) {
super(workerScript, workerOptions);
+ if (
+ this.workerOptions.elementsPerWorker === null ||
+ this.workerOptions.elementsPerWorker === undefined
+ ) {
+ throw new TypeError('Elements per worker is not defined');
+ }
+ if (!Number.isSafeInteger(this.workerOptions.elementsPerWorker)) {
+ throw new TypeError('Elements per worker must be an integer');
+ }
+ if (this.workerOptions.elementsPerWorker <= 0) {
+ throw new RangeError('Elements per worker must be greater than zero');
+ }
+ this.workerOptions.poolOptions = {
+ ...DEFAULT_POOL_OPTIONS,
+ ...this.workerOptions.poolOptions,
+ };
this.workerSet = new Set<WorkerSetElement>();
+ if (this.workerOptions.poolOptions?.enableEvents) {
+ this.emitter = new EventEmitter();
+ }
+ this.workerStartup = false;
+ }
+
+ get info(): SetInfo {
+ return {
+ version: workerSetVersion,
+ type: 'set',
+ worker: 'thread',
+ size: this.size,
+ elementsExecuting: [...this.workerSet].reduce(
+ (accumulator, workerSetElement) => accumulator + workerSetElement.numberOfWorkerElements,
+ 0,
+ ),
+ elementsPerWorker: this.maxElementsPerWorker!,
+ };
}
get size(): number {
return this.workerOptions.elementsPerWorker;
}
- /**
- *
- * @param elementData -
- * @returns
- * @public
- */
+ /** @inheritDoc */
+ public async start(): Promise<void> {
+ this.addWorkerSetElement();
+ // Add worker set element sequentially to optimize memory at startup
+ this.workerOptions.workerStartDelay! > 0 && (await sleep(this.workerOptions.workerStartDelay!));
+ }
+
+ /** @inheritDoc */
+ public async stop(): Promise<void> {
+ for (const workerSetElement of this.workerSet) {
+ const worker = workerSetElement.worker;
+ const waitWorkerExit = new Promise<void>((resolve) => {
+ worker.on('exit', () => {
+ resolve();
+ });
+ });
+ await worker.terminate();
+ await waitWorkerExit;
+ }
+ }
+
+ /** @inheritDoc */
public async addElement(elementData: WorkerData): Promise<void> {
if (!this.workerSet) {
throw new Error("Cannot add a WorkerSet element: workers' set does not exist");
}
- if (
- this.workerSet.size === 0 ||
- this.getLastWorkerSetElement().numberOfWorkerElements >= this.workerOptions.elementsPerWorker
- ) {
- await this.startWorker();
- }
- this.getLastWorker().postMessage({
- id: WorkerMessageEvents.startWorkerElement,
+ const workerSetElement = await this.getWorkerSetElement();
+ workerSetElement.worker.postMessage({
+ event: WorkerMessageEvents.startWorkerElement,
data: elementData,
});
- this.getLastWorkerSetElement().numberOfWorkerElements++;
- // Start element sequentially to optimize memory at startup
- if (this.workerOptions.elementStartDelay > 0) {
- await WorkerUtils.sleep(this.workerOptions.elementStartDelay);
- }
- }
-
- /**
- *
- * @returns
- * @public
- */
- public async start(): Promise<void> {
- await this.startWorker();
- }
-
- /**
- *
- * @returns
- * @public
- */
- public async stop(): Promise<void> {
- for (const workerSetElement of this.workerSet) {
- await workerSetElement.worker.terminate();
+ ++workerSetElement.numberOfWorkerElements;
+ // Add element sequentially to optimize memory at startup
+ if (this.workerOptions.elementStartDelay! > 0) {
+ await sleep(this.workerOptions.elementStartDelay!);
}
- this.workerSet.clear();
}
/**
- * Start a new `Worker`.
+ * Adds a new `WorkerSetElement`.
*/
- private async startWorker(): Promise<void> {
- const worker = new Worker(this.workerScript);
- worker.on(
- 'message',
- (this.workerOptions?.messageHandler ?? WorkerConstants.EMPTY_FUNCTION).bind(
- this
- ) as MessageHandler<Worker>
- );
- worker.on('error', WorkerUtils.defaultErrorHandler.bind(this) as (err: Error) => void);
- worker.on('exit', (code) => {
- WorkerUtils.defaultExitHandler(code);
- this.workerSet.delete(this.getWorkerSetElementByWorker(worker));
+ private addWorkerSetElement(): WorkerSetElement {
+ this.workerStartup = true;
+ const worker = new Worker(this.workerScript, {
+ env: SHARE_ENV,
+ ...this.workerOptions.poolOptions?.workerOptions,
});
- this.workerSet.add({ worker, numberOfWorkerElements: 0 });
- // Start worker sequentially to optimize memory at startup
- this.workerOptions.workerStartDelay > 0 &&
- (await WorkerUtils.sleep(this.workerOptions.workerStartDelay));
+ worker.on('message', this.workerOptions.poolOptions?.messageHandler ?? EMPTY_FUNCTION);
+ worker.on('message', (message: WorkerMessage<WorkerData>) => {
+ if (message.event === WorkerMessageEvents.startedWorkerElement) {
+ this.emitter?.emit(WorkerSetEvents.elementStarted, this.info);
+ } else if (message.event === WorkerMessageEvents.startWorkerElementError) {
+ this.emitter?.emit(WorkerSetEvents.elementError, message.data);
+ }
+ });
+ worker.on('error', this.workerOptions.poolOptions?.errorHandler ?? EMPTY_FUNCTION);
+ worker.on('error', (error) => {
+ this.emitter?.emit(WorkerSetEvents.error, error);
+ if (this.workerOptions.poolOptions?.restartWorkerOnError && !this.workerStartup) {
+ this.addWorkerSetElement();
+ }
+ });
+ worker.on('online', this.workerOptions.poolOptions?.onlineHandler ?? EMPTY_FUNCTION);
+ worker.on('exit', this.workerOptions.poolOptions?.exitHandler ?? EMPTY_FUNCTION);
+ worker.once('exit', () =>
+ this.removeWorkerSetElement(this.getWorkerSetElementByWorker(worker)!),
+ );
+ this.workerStartup = false;
+ const workerSetElement: WorkerSetElement = { worker, numberOfWorkerElements: 0 };
+ this.workerSet.add(workerSetElement);
+ return workerSetElement;
}
- private getLastWorkerSetElement(): WorkerSetElement {
- let workerSetElement: WorkerSetElement;
- for (workerSetElement of this.workerSet) {
- /* This is intentional */
- }
- return workerSetElement;
+ private removeWorkerSetElement(workerSetElement: WorkerSetElement): void {
+ this.workerSet.delete(workerSetElement);
}
- private getLastWorker(): Worker {
- return this.getLastWorkerSetElement().worker;
+ private async getWorkerSetElement(): Promise<WorkerSetElement> {
+ let chosenWorkerSetElement: WorkerSetElement | undefined;
+ for (const workerSetElement of this.workerSet) {
+ if (workerSetElement.numberOfWorkerElements < this.workerOptions.elementsPerWorker!) {
+ chosenWorkerSetElement = workerSetElement;
+ break;
+ }
+ }
+ if (!chosenWorkerSetElement) {
+ chosenWorkerSetElement = this.addWorkerSetElement();
+ // Add worker set element sequentially to optimize memory at startup
+ this.workerOptions.workerStartDelay! > 0 &&
+ (await sleep(this.workerOptions.workerStartDelay!));
+ }
+ return chosenWorkerSetElement;
}
- private getWorkerSetElementByWorker(worker: Worker): WorkerSetElement {
- let workerSetElt: WorkerSetElement;
+ private getWorkerSetElementByWorker(worker: Worker): WorkerSetElement | undefined {
+ let workerSetElt: WorkerSetElement | undefined;
for (const workerSetElement of this.workerSet) {
if (workerSetElement.worker.threadId === worker.threadId) {
workerSetElt = workerSetElement;