+import { randomUUID } from 'node:crypto'
+import { performance } from 'node:perf_hooks'
+import type { MessageValue, PromiseResponseWrapper } from '../utility-types'
+import {
+ DEFAULT_WORKER_CHOICE_STRATEGY_OPTIONS,
+ EMPTY_FUNCTION,
+ isKillBehavior,
+ isPlainObject,
+ median,
+ round
+} from '../utils'
+import { KillBehaviors } from '../worker/worker-options'
+import {
+ type IPool,
+ PoolEmitter,
+ PoolEvents,
+ type PoolInfo,
+ type PoolOptions,
+ type PoolType,
+ PoolTypes,
+ type TasksQueueOptions
+} from './pool'
import type {
- MessageValue,
- PromiseWorkerResponseWrapper
-} from '../utility-types'
-import type { IPoolInternal } from './pool-internal'
-import { PoolEmitter } from './pool-internal'
-import type { WorkerChoiceStrategy } from './selection-strategies'
+ IWorker,
+ IWorkerNode,
+ MessageHandler,
+ Task,
+ WorkerInfo,
+ WorkerType,
+ WorkerUsage
+} from './worker'
import {
+ Measurements,
WorkerChoiceStrategies,
- WorkerChoiceStrategyContext
-} from './selection-strategies'
-
-/**
- * An intentional empty function.
- */
-const EMPTY_FUNCTION: () => void = () => {
- /* Intentionally empty */
-}
+ type WorkerChoiceStrategy,
+ type WorkerChoiceStrategyOptions
+} from './selection-strategies/selection-strategies-types'
+import { WorkerChoiceStrategyContext } from './selection-strategies/worker-choice-strategy-context'
+import { version } from './version'
+import { WorkerNode } from './worker-node'
/**
- * Callback invoked if the worker raised an error.
- */
-export type ErrorHandler<Worker> = (this: Worker, e: Error) => void
-
-/**
- * Callback invoked when the worker has started successfully.
+ * Base class that implements some shared logic for all poolifier pools.
+ *
+ * @typeParam Worker - Type of worker which manages this pool.
+ * @typeParam Data - Type of data sent to the worker. This can only be structured-cloneable data.
+ * @typeParam Response - Type of execution response. This can only be structured-cloneable data.
*/
-export type OnlineHandler<Worker> = (this: Worker) => void
+export abstract class AbstractPool<
+ Worker extends IWorker,
+ Data = unknown,
+ Response = unknown
+> implements IPool<Worker, Data, Response> {
+ /** @inheritDoc */
+ public readonly workerNodes: Array<IWorkerNode<Worker, Data>> = []
-/**
- * Callback invoked when the worker exits successfully.
- */
-export type ExitHandler<Worker> = (this: Worker, code: number) => void
+ /** @inheritDoc */
+ public readonly emitter?: PoolEmitter
-/**
- * Basic interface that describes the minimum required implementation of listener events for a pool-worker.
- */
-export interface IWorker {
/**
- * Register a listener to the error event.
+ * The execution response promise map.
*
- * @param event `'error'`.
- * @param handler The error handler.
- */
- on(event: 'error', handler: ErrorHandler<this>): void
- /**
- * Register a listener to the online event.
+ * - `key`: The message id of each submitted task.
+ * - `value`: An object that contains the worker, the execution response promise resolve and reject callbacks.
*
- * @param event `'online'`.
- * @param handler The online handler.
+ * When we receive a message from the worker, we get a map entry with the promise resolve/reject bound to the message id.
*/
- on(event: 'online', handler: OnlineHandler<this>): void
+ protected promiseResponseMap: Map<
+ string,
+ PromiseResponseWrapper<Worker, Response>
+ > = new Map<string, PromiseResponseWrapper<Worker, Response>>()
+
/**
- * Register a listener to the exit event.
- *
- * @param event `'exit'`.
- * @param handler The exit handler.
+ * Worker choice strategy context referencing a worker choice algorithm implementation.
*/
- on(event: 'exit', handler: ExitHandler<this>): void
- /**
- * Register a listener to the exit event that will only performed once.
- *
- * @param event `'exit'`.
- * @param handler The exit handler.
- */
- once(event: 'exit', handler: ExitHandler<this>): void
-}
+ protected workerChoiceStrategyContext: WorkerChoiceStrategyContext<
+ Worker,
+ Data,
+ Response
+ >
-/**
- * Options for a poolifier pool.
- */
-export interface PoolOptions<Worker> {
/**
- * A function that will listen for error event on each worker.
+ * The start timestamp of the pool.
*/
- errorHandler?: ErrorHandler<Worker>
+ private readonly startTimestamp
+
/**
- * A function that will listen for online event on each worker.
+ * Constructs a new poolifier pool.
+ *
+ * @param numberOfWorkers - Number of workers that this pool should manage.
+ * @param filePath - Path to the worker file.
+ * @param opts - Options for the pool.
*/
- onlineHandler?: OnlineHandler<Worker>
+ public constructor (
+ protected readonly numberOfWorkers: number,
+ protected readonly filePath: string,
+ protected readonly opts: PoolOptions<Worker>
+ ) {
+ if (!this.isMain()) {
+ throw new Error('Cannot start a pool from a worker!')
+ }
+ this.checkNumberOfWorkers(this.numberOfWorkers)
+ this.checkFilePath(this.filePath)
+ this.checkPoolOptions(this.opts)
+
+ this.chooseWorkerNode = this.chooseWorkerNode.bind(this)
+ this.executeTask = this.executeTask.bind(this)
+ this.enqueueTask = this.enqueueTask.bind(this)
+ this.checkAndEmitEvents = this.checkAndEmitEvents.bind(this)
+
+ if (this.opts.enableEvents === true) {
+ this.emitter = new PoolEmitter()
+ }
+ this.workerChoiceStrategyContext = new WorkerChoiceStrategyContext<
+ Worker,
+ Data,
+ Response
+ >(
+ this,
+ this.opts.workerChoiceStrategy,
+ this.opts.workerChoiceStrategyOptions
+ )
+
+ this.setupHook()
+
+ while (this.workerNodes.length < this.numberOfWorkers) {
+ this.createAndSetupWorker()
+ }
+
+ this.startTimestamp = performance.now()
+ }
+
+ private checkFilePath (filePath: string): void {
+ if (
+ filePath == null ||
+ (typeof filePath === 'string' && filePath.trim().length === 0)
+ ) {
+ throw new Error('Please specify a file with a worker implementation')
+ }
+ }
+
+ private checkNumberOfWorkers (numberOfWorkers: number): void {
+ if (numberOfWorkers == null) {
+ throw new Error(
+ 'Cannot instantiate a pool without specifying the number of workers'
+ )
+ } else if (!Number.isSafeInteger(numberOfWorkers)) {
+ throw new TypeError(
+ 'Cannot instantiate a pool with a non safe integer number of workers'
+ )
+ } else if (numberOfWorkers < 0) {
+ throw new RangeError(
+ 'Cannot instantiate a pool with a negative number of workers'
+ )
+ } else if (this.type === PoolTypes.fixed && numberOfWorkers === 0) {
+ throw new RangeError('Cannot instantiate a fixed pool with zero worker')
+ }
+ }
+
+ protected checkDynamicPoolSize (min: number, max: number): void {
+ if (this.type === PoolTypes.dynamic && min > max) {
+ throw new RangeError(
+ 'Cannot instantiate a dynamic pool with a maximum pool size inferior to the minimum pool size'
+ )
+ } else if (this.type === PoolTypes.dynamic && min === 0 && max === 0) {
+ throw new RangeError(
+ 'Cannot instantiate a dynamic pool with a minimum pool size and a maximum pool size equal to zero'
+ )
+ } else if (this.type === PoolTypes.dynamic && min === max) {
+ throw new RangeError(
+ 'Cannot instantiate a dynamic pool with a minimum pool size equal to the maximum pool size. Use a fixed pool instead'
+ )
+ }
+ }
+
+ private checkPoolOptions (opts: PoolOptions<Worker>): void {
+ if (isPlainObject(opts)) {
+ this.opts.workerChoiceStrategy =
+ opts.workerChoiceStrategy ?? WorkerChoiceStrategies.ROUND_ROBIN
+ this.checkValidWorkerChoiceStrategy(this.opts.workerChoiceStrategy)
+ this.opts.workerChoiceStrategyOptions =
+ opts.workerChoiceStrategyOptions ??
+ DEFAULT_WORKER_CHOICE_STRATEGY_OPTIONS
+ this.checkValidWorkerChoiceStrategyOptions(
+ this.opts.workerChoiceStrategyOptions
+ )
+ this.opts.restartWorkerOnError = opts.restartWorkerOnError ?? true
+ this.opts.enableEvents = opts.enableEvents ?? true
+ this.opts.enableTasksQueue = opts.enableTasksQueue ?? false
+ if (this.opts.enableTasksQueue) {
+ this.checkValidTasksQueueOptions(
+ opts.tasksQueueOptions as TasksQueueOptions
+ )
+ this.opts.tasksQueueOptions = this.buildTasksQueueOptions(
+ opts.tasksQueueOptions as TasksQueueOptions
+ )
+ }
+ } else {
+ throw new TypeError('Invalid pool options: must be a plain object')
+ }
+ }
+
+ private checkValidWorkerChoiceStrategy (
+ workerChoiceStrategy: WorkerChoiceStrategy
+ ): void {
+ if (!Object.values(WorkerChoiceStrategies).includes(workerChoiceStrategy)) {
+ throw new Error(
+ `Invalid worker choice strategy '${workerChoiceStrategy}'`
+ )
+ }
+ }
+
+ private checkValidWorkerChoiceStrategyOptions (
+ workerChoiceStrategyOptions: WorkerChoiceStrategyOptions
+ ): void {
+ if (!isPlainObject(workerChoiceStrategyOptions)) {
+ throw new TypeError(
+ 'Invalid worker choice strategy options: must be a plain object'
+ )
+ }
+ if (
+ workerChoiceStrategyOptions.weights != null &&
+ Object.keys(workerChoiceStrategyOptions.weights).length !== this.maxSize
+ ) {
+ throw new Error(
+ 'Invalid worker choice strategy options: must have a weight for each worker node'
+ )
+ }
+ if (
+ workerChoiceStrategyOptions.measurement != null &&
+ !Object.values(Measurements).includes(
+ workerChoiceStrategyOptions.measurement
+ )
+ ) {
+ throw new Error(
+ `Invalid worker choice strategy options: invalid measurement '${workerChoiceStrategyOptions.measurement}'`
+ )
+ }
+ }
+
+ private checkValidTasksQueueOptions (
+ tasksQueueOptions: TasksQueueOptions
+ ): void {
+ if (tasksQueueOptions != null && !isPlainObject(tasksQueueOptions)) {
+ throw new TypeError('Invalid tasks queue options: must be a plain object')
+ }
+ if (
+ tasksQueueOptions?.concurrency != null &&
+ !Number.isSafeInteger(tasksQueueOptions.concurrency)
+ ) {
+ throw new TypeError(
+ 'Invalid worker tasks concurrency: must be an integer'
+ )
+ }
+ if (
+ tasksQueueOptions?.concurrency != null &&
+ tasksQueueOptions.concurrency <= 0
+ ) {
+ throw new Error(
+ `Invalid worker tasks concurrency '${tasksQueueOptions.concurrency}'`
+ )
+ }
+ }
+
+ /** @inheritDoc */
+ public get info (): PoolInfo {
+ return {
+ version,
+ type: this.type,
+ worker: this.worker,
+ ready: this.ready,
+ strategy: this.opts.workerChoiceStrategy as WorkerChoiceStrategy,
+ minSize: this.minSize,
+ maxSize: this.maxSize,
+ ...(this.workerChoiceStrategyContext.getTaskStatisticsRequirements()
+ .runTime.aggregate &&
+ this.workerChoiceStrategyContext.getTaskStatisticsRequirements()
+ .waitTime.aggregate && { utilization: round(this.utilization) }),
+ workerNodes: this.workerNodes.length,
+ idleWorkerNodes: this.workerNodes.reduce(
+ (accumulator, workerNode) =>
+ workerNode.usage.tasks.executing === 0
+ ? accumulator + 1
+ : accumulator,
+ 0
+ ),
+ busyWorkerNodes: this.workerNodes.reduce(
+ (accumulator, workerNode) =>
+ workerNode.usage.tasks.executing > 0 ? accumulator + 1 : accumulator,
+ 0
+ ),
+ executedTasks: this.workerNodes.reduce(
+ (accumulator, workerNode) =>
+ accumulator + workerNode.usage.tasks.executed,
+ 0
+ ),
+ executingTasks: this.workerNodes.reduce(
+ (accumulator, workerNode) =>
+ accumulator + workerNode.usage.tasks.executing,
+ 0
+ ),
+ queuedTasks: this.workerNodes.reduce(
+ (accumulator, workerNode) =>
+ accumulator + workerNode.usage.tasks.queued,
+ 0
+ ),
+ maxQueuedTasks: this.workerNodes.reduce(
+ (accumulator, workerNode) =>
+ accumulator + workerNode.usage.tasks.maxQueued,
+ 0
+ ),
+ failedTasks: this.workerNodes.reduce(
+ (accumulator, workerNode) =>
+ accumulator + workerNode.usage.tasks.failed,
+ 0
+ ),
+ ...(this.workerChoiceStrategyContext.getTaskStatisticsRequirements()
+ .runTime.aggregate && {
+ runTime: {
+ minimum: round(
+ Math.min(
+ ...this.workerNodes.map(
+ workerNode => workerNode.usage.runTime?.minimum ?? Infinity
+ )
+ )
+ ),
+ maximum: round(
+ Math.max(
+ ...this.workerNodes.map(
+ workerNode => workerNode.usage.runTime?.maximum ?? -Infinity
+ )
+ )
+ ),
+ average: round(
+ this.workerNodes.reduce(
+ (accumulator, workerNode) =>
+ accumulator + (workerNode.usage.runTime?.aggregate ?? 0),
+ 0
+ ) /
+ this.workerNodes.reduce(
+ (accumulator, workerNode) =>
+ accumulator + (workerNode.usage.tasks?.executed ?? 0),
+ 0
+ )
+ ),
+ ...(this.workerChoiceStrategyContext.getTaskStatisticsRequirements()
+ .runTime.median && {
+ median: round(
+ median(
+ this.workerNodes.map(
+ workerNode => workerNode.usage.runTime?.median ?? 0
+ )
+ )
+ )
+ })
+ }
+ }),
+ ...(this.workerChoiceStrategyContext.getTaskStatisticsRequirements()
+ .waitTime.aggregate && {
+ waitTime: {
+ minimum: round(
+ Math.min(
+ ...this.workerNodes.map(
+ workerNode => workerNode.usage.waitTime?.minimum ?? Infinity
+ )
+ )
+ ),
+ maximum: round(
+ Math.max(
+ ...this.workerNodes.map(
+ workerNode => workerNode.usage.waitTime?.maximum ?? -Infinity
+ )
+ )
+ ),
+ average: round(
+ this.workerNodes.reduce(
+ (accumulator, workerNode) =>
+ accumulator + (workerNode.usage.waitTime?.aggregate ?? 0),
+ 0
+ ) /
+ this.workerNodes.reduce(
+ (accumulator, workerNode) =>
+ accumulator + (workerNode.usage.tasks?.executed ?? 0),
+ 0
+ )
+ ),
+ ...(this.workerChoiceStrategyContext.getTaskStatisticsRequirements()
+ .waitTime.median && {
+ median: round(
+ median(
+ this.workerNodes.map(
+ workerNode => workerNode.usage.waitTime?.median ?? 0
+ )
+ )
+ )
+ })
+ }
+ })
+ }
+ }
+
+ private get starting (): boolean {
+ return (
+ !this.full ||
+ (this.full && this.workerNodes.some(workerNode => !workerNode.info.ready))
+ )
+ }
+
+ private get ready (): boolean {
+ return (
+ this.full && this.workerNodes.every(workerNode => workerNode.info.ready)
+ )
+ }
+
/**
- * A function that will listen for exit event on each worker.
+ * Gets the approximate pool utilization.
+ *
+ * @returns The pool utilization.
*/
- exitHandler?: ExitHandler<Worker>
+ private get utilization (): number {
+ const poolRunTimeCapacity =
+ (performance.now() - this.startTimestamp) * this.maxSize
+ const totalTasksRunTime = this.workerNodes.reduce(
+ (accumulator, workerNode) =>
+ accumulator + (workerNode.usage.runTime?.aggregate ?? 0),
+ 0
+ )
+ const totalTasksWaitTime = this.workerNodes.reduce(
+ (accumulator, workerNode) =>
+ accumulator + (workerNode.usage.waitTime?.aggregate ?? 0),
+ 0
+ )
+ return (totalTasksRunTime + totalTasksWaitTime) / poolRunTimeCapacity
+ }
+
/**
- * This is just to avoid non-useful warning messages.
- *
- * Will be used to set `maxListeners` on event emitters (workers are event emitters).
+ * Pool type.
*
- * @default 1000
- * @see [Node events emitter.setMaxListeners(n)](https://nodejs.org/api/events.html#events_emitter_setmaxlisteners_n)
+ * If it is `'dynamic'`, it provides the `max` property.
*/
- maxTasks?: number
+ protected abstract get type (): PoolType
+
/**
- * The work choice strategy to use in this pool.
+ * Gets the worker type.
*/
- workerChoiceStrategy?: WorkerChoiceStrategy
-}
+ protected abstract get worker (): WorkerType
-/**
- * Base class containing some shared logic for all poolifier pools.
- *
- * @template Worker Type of worker which manages this pool.
- * @template Data Type of data sent to the worker. This can only be serializable data.
- * @template Response Type of response of execution. This can only be serializable data.
- */
-export abstract class AbstractPool<
- Worker extends IWorker,
- Data = unknown,
- Response = unknown
-> implements IPoolInternal<Worker, Data, Response> {
/**
- * The promise map.
- *
- * - `key`: This is the message ID of each submitted task.
- * - `value`: An object that contains the worker, the resolve function and the reject function.
- *
- * When we receive a message from the worker we get a map entry and resolve/reject the promise based on the message.
+ * Pool minimum size.
*/
- protected promiseMap: Map<
- number,
- PromiseWorkerResponseWrapper<Worker, Response>
- > = new Map<number, PromiseWorkerResponseWrapper<Worker, Response>>()
-
- /** @inheritdoc */
- public readonly workers: Worker[] = []
-
- /** @inheritdoc */
- public readonly tasks: Map<Worker, number> = new Map<Worker, number>()
-
- /** @inheritdoc */
- public readonly emitter: PoolEmitter
+ protected abstract get minSize (): number
/**
- * ID of the next message.
+ * Pool maximum size.
*/
- protected nextMessageId: number = 0
+ protected abstract get maxSize (): number
/**
- * Worker choice strategy instance implementing the worker choice algorithm.
+ * Get the worker given its id.
*
- * Default to a strategy implementing a round robin algorithm.
+ * @param workerId - The worker id.
+ * @returns The worker if found in the pool worker nodes, `undefined` otherwise.
*/
- protected workerChoiceStrategyContext: WorkerChoiceStrategyContext<
- Worker,
- Data,
- Response
- >
+ private getWorkerById (workerId: number): Worker | undefined {
+ return this.workerNodes.find(workerNode => workerNode.info.id === workerId)
+ ?.worker
+ }
+
+ private checkMessageWorkerId (message: MessageValue<Response>): void {
+ if (
+ message.workerId != null &&
+ this.getWorkerById(message.workerId) == null
+ ) {
+ throw new Error(
+ `Worker message received from unknown worker '${message.workerId}'`
+ )
+ }
+ }
/**
- * Constructs a new poolifier pool.
+ * Gets the given worker its worker node key.
*
- * @param numberOfWorkers Number of workers that this pool should manage.
- * @param filePath Path to the worker-file.
- * @param opts Options for the pool. Default: `{ maxTasks: 1000 }`
+ * @param worker - The worker.
+ * @returns The worker node key if found in the pool worker nodes, `-1` otherwise.
*/
- public constructor (
- public readonly numberOfWorkers: number,
- public readonly filePath: string,
- public readonly opts: PoolOptions<Worker> = { maxTasks: 1000 }
- ) {
- if (!this.isMain()) {
- throw new Error('Cannot start a pool from a worker!')
- }
- this.checkFilePath(this.filePath)
- this.setupHook()
+ private getWorkerNodeKey (worker: Worker): number {
+ return this.workerNodes.findIndex(
+ workerNode => workerNode.worker === worker
+ )
+ }
- for (let i = 1; i <= this.numberOfWorkers; i++) {
- this.createAndSetupWorker()
+ /** @inheritDoc */
+ public setWorkerChoiceStrategy (
+ workerChoiceStrategy: WorkerChoiceStrategy,
+ workerChoiceStrategyOptions?: WorkerChoiceStrategyOptions
+ ): void {
+ this.checkValidWorkerChoiceStrategy(workerChoiceStrategy)
+ this.opts.workerChoiceStrategy = workerChoiceStrategy
+ this.workerChoiceStrategyContext.setWorkerChoiceStrategy(
+ this.opts.workerChoiceStrategy
+ )
+ if (workerChoiceStrategyOptions != null) {
+ this.setWorkerChoiceStrategyOptions(workerChoiceStrategyOptions)
}
+ for (const workerNode of this.workerNodes) {
+ workerNode.resetUsage()
+ this.setWorkerStatistics(workerNode.worker)
+ }
+ }
- this.emitter = new PoolEmitter()
- this.workerChoiceStrategyContext = new WorkerChoiceStrategyContext(
- this,
- opts.workerChoiceStrategy ?? WorkerChoiceStrategies.ROUND_ROBIN
+ /** @inheritDoc */
+ public setWorkerChoiceStrategyOptions (
+ workerChoiceStrategyOptions: WorkerChoiceStrategyOptions
+ ): void {
+ this.checkValidWorkerChoiceStrategyOptions(workerChoiceStrategyOptions)
+ this.opts.workerChoiceStrategyOptions = workerChoiceStrategyOptions
+ this.workerChoiceStrategyContext.setOptions(
+ this.opts.workerChoiceStrategyOptions
)
}
- private checkFilePath (filePath: string): void {
- if (!filePath) {
- throw new Error('Please specify a file with a worker implementation')
+ /** @inheritDoc */
+ public enableTasksQueue (
+ enable: boolean,
+ tasksQueueOptions?: TasksQueueOptions
+ ): void {
+ if (this.opts.enableTasksQueue === true && !enable) {
+ this.flushTasksQueues()
}
+ this.opts.enableTasksQueue = enable
+ this.setTasksQueueOptions(tasksQueueOptions as TasksQueueOptions)
}
- /** @inheritdoc */
- public isDynamic (): boolean {
- return false
+ /** @inheritDoc */
+ public setTasksQueueOptions (tasksQueueOptions: TasksQueueOptions): void {
+ if (this.opts.enableTasksQueue === true) {
+ this.checkValidTasksQueueOptions(tasksQueueOptions)
+ this.opts.tasksQueueOptions =
+ this.buildTasksQueueOptions(tasksQueueOptions)
+ } else if (this.opts.tasksQueueOptions != null) {
+ delete this.opts.tasksQueueOptions
+ }
}
- /** @inheritdoc */
- public setWorkerChoiceStrategy (
- workerChoiceStrategy: WorkerChoiceStrategy
- ): void {
- this.workerChoiceStrategyContext.setWorkerChoiceStrategy(
- workerChoiceStrategy
+ private buildTasksQueueOptions (
+ tasksQueueOptions: TasksQueueOptions
+ ): TasksQueueOptions {
+ return {
+ concurrency: tasksQueueOptions?.concurrency ?? 1
+ }
+ }
+
+ /**
+ * Whether the pool is full or not.
+ *
+ * The pool filling boolean status.
+ */
+ protected get full (): boolean {
+ return this.workerNodes.length >= this.maxSize
+ }
+
+ /**
+ * Whether the pool is busy or not.
+ *
+ * The pool busyness boolean status.
+ */
+ protected abstract get busy (): boolean
+
+ /**
+ * Whether worker nodes are executing at least one task.
+ *
+ * @returns Worker nodes busyness boolean status.
+ */
+ protected internalBusy (): boolean {
+ return (
+ this.workerNodes.findIndex(workerNode => {
+ return workerNode.usage.tasks.executing === 0
+ }) === -1
)
}
- /** @inheritdoc */
- public execute (data: Data): Promise<Response> {
- // Configure worker to handle message with the specified task
- const worker = this.chooseWorker()
- this.increaseWorkersTask(worker)
- const messageId = ++this.nextMessageId
- const res = this.internalExecute(worker, messageId)
- this.sendToWorker(worker, { data: data || ({} as Data), id: messageId })
+ /** @inheritDoc */
+ public async execute (data?: Data, name?: string): Promise<Response> {
+ const timestamp = performance.now()
+ const workerNodeKey = this.chooseWorkerNode()
+ const submittedTask: Task<Data> = {
+ name,
+ // eslint-disable-next-line @typescript-eslint/consistent-type-assertions
+ data: data ?? ({} as Data),
+ timestamp,
+ workerId: this.getWorkerInfo(workerNodeKey).id as number,
+ id: randomUUID()
+ }
+ const res = new Promise<Response>((resolve, reject) => {
+ this.promiseResponseMap.set(submittedTask.id as string, {
+ resolve,
+ reject,
+ worker: this.workerNodes[workerNodeKey].worker
+ })
+ })
+ if (
+ this.opts.enableTasksQueue === true &&
+ (this.busy ||
+ this.workerNodes[workerNodeKey].usage.tasks.executing >=
+ ((this.opts.tasksQueueOptions as TasksQueueOptions)
+ .concurrency as number))
+ ) {
+ this.enqueueTask(workerNodeKey, submittedTask)
+ } else {
+ this.executeTask(workerNodeKey, submittedTask)
+ }
+ this.checkAndEmitEvents()
+ // eslint-disable-next-line @typescript-eslint/return-await
return res
}
- /** @inheritdoc */
+ /** @inheritDoc */
public async destroy (): Promise<void> {
- await Promise.all(this.workers.map(worker => this.destroyWorker(worker)))
+ await Promise.all(
+ this.workerNodes.map(async (workerNode, workerNodeKey) => {
+ this.flushTasksQueue(workerNodeKey)
+ // FIXME: wait for tasks to be finished
+ const workerExitPromise = new Promise<void>(resolve => {
+ workerNode.worker.on('exit', () => {
+ resolve()
+ })
+ })
+ await this.destroyWorker(workerNode.worker)
+ await workerExitPromise
+ })
+ )
}
- /** @inheritdoc */
- public abstract destroyWorker (worker: Worker): void | Promise<void>
+ /**
+ * Terminates the given worker.
+ *
+ * @param worker - A worker within `workerNodes`.
+ */
+ protected abstract destroyWorker (worker: Worker): void | Promise<void>
/**
- * Setup hook that can be overridden by a Poolifier pool implementation
- * to run code before workers are created in the abstract constructor.
+ * Setup hook to execute code before worker nodes are created in the abstract constructor.
+ * Can be overridden.
+ *
+ * @virtual
*/
protected setupHook (): void {
- // Can be overridden
+ // Intentionally empty
}
/**
protected abstract isMain (): boolean
/**
- * Increase the number of tasks that the given workers has done.
+ * Hook executed before the worker task execution.
+ * Can be overridden.
*
- * @param worker Worker whose tasks are increased.
+ * @param workerNodeKey - The worker node key.
+ * @param task - The task to execute.
*/
- protected increaseWorkersTask (worker: Worker): void {
- this.stepWorkerNumberOfTasks(worker, 1)
+ protected beforeTaskExecutionHook (
+ workerNodeKey: number,
+ task: Task<Data>
+ ): void {
+ const workerUsage = this.workerNodes[workerNodeKey].usage
+ ++workerUsage.tasks.executing
+ this.updateWaitTimeWorkerUsage(workerUsage, task)
}
/**
- * Decrease the number of tasks that the given workers has done.
+ * Hook executed after the worker task execution.
+ * Can be overridden.
*
- * @param worker Worker whose tasks are decreased.
+ * @param worker - The worker.
+ * @param message - The received message.
*/
- protected decreaseWorkersTasks (worker: Worker): void {
- this.stepWorkerNumberOfTasks(worker, -1)
+ protected afterTaskExecutionHook (
+ worker: Worker,
+ message: MessageValue<Response>
+ ): void {
+ const workerUsage = this.workerNodes[this.getWorkerNodeKey(worker)].usage
+ this.updateTaskStatisticsWorkerUsage(workerUsage, message)
+ this.updateRunTimeWorkerUsage(workerUsage, message)
+ this.updateEluWorkerUsage(workerUsage, message)
}
- /**
- * Step the number of tasks that the given workers has done.
- *
- * @param worker Worker whose tasks are set.
- * @param step Worker number of tasks step.
- */
- private stepWorkerNumberOfTasks (worker: Worker, step: number): void {
- const numberOfTasksInProgress = this.tasks.get(worker)
- if (numberOfTasksInProgress !== undefined) {
- this.tasks.set(worker, numberOfTasksInProgress + step)
+ private updateTaskStatisticsWorkerUsage (
+ workerUsage: WorkerUsage,
+ message: MessageValue<Response>
+ ): void {
+ const workerTaskStatistics = workerUsage.tasks
+ --workerTaskStatistics.executing
+ if (message.taskError == null) {
+ ++workerTaskStatistics.executed
} else {
- throw Error('Worker could not be found in tasks map')
+ ++workerTaskStatistics.failed
+ }
+ }
+
+ private updateRunTimeWorkerUsage (
+ workerUsage: WorkerUsage,
+ message: MessageValue<Response>
+ ): void {
+ if (
+ this.workerChoiceStrategyContext.getTaskStatisticsRequirements().runTime
+ .aggregate
+ ) {
+ const taskRunTime = message.taskPerformance?.runTime ?? 0
+ workerUsage.runTime.aggregate =
+ (workerUsage.runTime.aggregate ?? 0) + taskRunTime
+ workerUsage.runTime.minimum = Math.min(
+ taskRunTime,
+ workerUsage.runTime?.minimum ?? Infinity
+ )
+ workerUsage.runTime.maximum = Math.max(
+ taskRunTime,
+ workerUsage.runTime?.maximum ?? -Infinity
+ )
+ if (
+ this.workerChoiceStrategyContext.getTaskStatisticsRequirements().runTime
+ .average &&
+ workerUsage.tasks.executed !== 0
+ ) {
+ workerUsage.runTime.average =
+ workerUsage.runTime.aggregate / workerUsage.tasks.executed
+ }
+ if (
+ this.workerChoiceStrategyContext.getTaskStatisticsRequirements().runTime
+ .median &&
+ message.taskPerformance?.runTime != null
+ ) {
+ workerUsage.runTime.history.push(message.taskPerformance.runTime)
+ workerUsage.runTime.median = median(workerUsage.runTime.history)
+ }
+ }
+ }
+
+ private updateWaitTimeWorkerUsage (
+ workerUsage: WorkerUsage,
+ task: Task<Data>
+ ): void {
+ const timestamp = performance.now()
+ const taskWaitTime = timestamp - (task.timestamp ?? timestamp)
+ if (
+ this.workerChoiceStrategyContext.getTaskStatisticsRequirements().waitTime
+ .aggregate
+ ) {
+ workerUsage.waitTime.aggregate =
+ (workerUsage.waitTime?.aggregate ?? 0) + taskWaitTime
+ workerUsage.waitTime.minimum = Math.min(
+ taskWaitTime,
+ workerUsage.waitTime?.minimum ?? Infinity
+ )
+ workerUsage.waitTime.maximum = Math.max(
+ taskWaitTime,
+ workerUsage.waitTime?.maximum ?? -Infinity
+ )
+ if (
+ this.workerChoiceStrategyContext.getTaskStatisticsRequirements()
+ .waitTime.average &&
+ workerUsage.tasks.executed !== 0
+ ) {
+ workerUsage.waitTime.average =
+ workerUsage.waitTime.aggregate / workerUsage.tasks.executed
+ }
+ if (
+ this.workerChoiceStrategyContext.getTaskStatisticsRequirements()
+ .waitTime.median
+ ) {
+ workerUsage.waitTime.history.push(taskWaitTime)
+ workerUsage.waitTime.median = median(workerUsage.waitTime.history)
+ }
+ }
+ }
+
+ private updateEluWorkerUsage (
+ workerUsage: WorkerUsage,
+ message: MessageValue<Response>
+ ): void {
+ if (
+ this.workerChoiceStrategyContext.getTaskStatisticsRequirements().elu
+ .aggregate
+ ) {
+ if (message.taskPerformance?.elu != null) {
+ workerUsage.elu.idle.aggregate =
+ (workerUsage.elu.idle?.aggregate ?? 0) +
+ message.taskPerformance.elu.idle
+ workerUsage.elu.active.aggregate =
+ (workerUsage.elu.active?.aggregate ?? 0) +
+ message.taskPerformance.elu.active
+ if (workerUsage.elu.utilization != null) {
+ workerUsage.elu.utilization =
+ (workerUsage.elu.utilization +
+ message.taskPerformance.elu.utilization) /
+ 2
+ } else {
+ workerUsage.elu.utilization = message.taskPerformance.elu.utilization
+ }
+ workerUsage.elu.idle.minimum = Math.min(
+ message.taskPerformance.elu.idle,
+ workerUsage.elu.idle?.minimum ?? Infinity
+ )
+ workerUsage.elu.idle.maximum = Math.max(
+ message.taskPerformance.elu.idle,
+ workerUsage.elu.idle?.maximum ?? -Infinity
+ )
+ workerUsage.elu.active.minimum = Math.min(
+ message.taskPerformance.elu.active,
+ workerUsage.elu.active?.minimum ?? Infinity
+ )
+ workerUsage.elu.active.maximum = Math.max(
+ message.taskPerformance.elu.active,
+ workerUsage.elu.active?.maximum ?? -Infinity
+ )
+ if (
+ this.workerChoiceStrategyContext.getTaskStatisticsRequirements().elu
+ .average &&
+ workerUsage.tasks.executed !== 0
+ ) {
+ workerUsage.elu.idle.average =
+ workerUsage.elu.idle.aggregate / workerUsage.tasks.executed
+ workerUsage.elu.active.average =
+ workerUsage.elu.active.aggregate / workerUsage.tasks.executed
+ }
+ if (
+ this.workerChoiceStrategyContext.getTaskStatisticsRequirements().elu
+ .median
+ ) {
+ workerUsage.elu.idle.history.push(message.taskPerformance.elu.idle)
+ workerUsage.elu.active.history.push(
+ message.taskPerformance.elu.active
+ )
+ workerUsage.elu.idle.median = median(workerUsage.elu.idle.history)
+ workerUsage.elu.active.median = median(workerUsage.elu.active.history)
+ }
+ }
}
}
/**
- * Removes the given worker from the pool.
+ * Chooses a worker node for the next task.
+ *
+ * The default worker choice strategy uses a round robin algorithm to distribute the tasks.
*
- * @param worker Worker that will be removed.
+ * @returns The worker node key
*/
- protected removeWorker (worker: Worker): void {
- // Clean worker from data structure
- const workerIndex = this.workers.indexOf(worker)
- this.workers.splice(workerIndex, 1)
- this.tasks.delete(worker)
+ private chooseWorkerNode (): number {
+ if (this.shallCreateDynamicWorker()) {
+ const worker = this.createAndSetupDynamicWorker()
+ if (
+ this.workerChoiceStrategyContext.getStrategyPolicy().useDynamicWorker
+ ) {
+ return this.getWorkerNodeKey(worker)
+ }
+ }
+ return this.workerChoiceStrategyContext.execute()
}
/**
- * Choose a worker for the next task.
- *
- * The default implementation uses a round robin algorithm to distribute the load.
+ * Conditions for dynamic worker creation.
*
- * @returns Worker.
+ * @returns Whether to create a dynamic worker or not.
*/
- protected chooseWorker (): Worker {
- return this.workerChoiceStrategyContext.execute()
+ private shallCreateDynamicWorker (): boolean {
+ return this.type === PoolTypes.dynamic && !this.full && this.internalBusy()
}
/**
- * Send a message to the given worker.
+ * Sends a message to the given worker.
*
- * @param worker The worker which should receive the message.
- * @param message The message.
+ * @param worker - The worker which should receive the message.
+ * @param message - The message.
*/
protected abstract sendToWorker (
worker: Worker,
message: MessageValue<Data>
): void
- /** @inheritdoc */
- public abstract registerWorkerMessageListener<
- Message extends Data | Response
- > (worker: Worker, listener: (message: MessageValue<Message>) => void): void
-
- protected internalExecute (
+ /**
+ * Registers a listener callback on the given worker.
+ *
+ * @param worker - The worker which should register a listener.
+ * @param listener - The message listener callback.
+ */
+ private registerWorkerMessageListener<Message extends Data | Response>(
worker: Worker,
- messageId: number
- ): Promise<Response> {
- return new Promise<Response>((resolve, reject) => {
- this.promiseMap.set(messageId, { resolve, reject, worker })
- })
+ listener: (message: MessageValue<Message>) => void
+ ): void {
+ worker.on('message', listener as MessageHandler<Worker>)
}
/**
- * Returns a newly created worker.
+ * Creates a new worker.
+ *
+ * @returns Newly created worker.
*/
protected abstract createWorker (): Worker
/**
- * Function that can be hooked up when a worker has been newly created and moved to the workers registry.
- *
- * Can be used to update the `maxListeners` or binding the `main-worker`<->`worker` connection if not bind by default.
+ * Function that can be hooked up when a worker has been newly created and moved to the pool worker nodes.
+ * Can be overridden.
*
- * @param worker The newly created worker.
+ * @param worker - The newly created worker.
*/
- protected abstract afterWorkerSetup (worker: Worker): void
+ protected afterWorkerSetup (worker: Worker): void {
+ // Listen to worker messages.
+ this.registerWorkerMessageListener(worker, this.workerListener())
+ // Send startup message to worker.
+ this.sendToWorker(worker, {
+ ready: false,
+ workerId: this.getWorkerInfo(this.getWorkerNodeKey(worker)).id as number
+ })
+ // Setup worker task statistics computation.
+ this.setWorkerStatistics(worker)
+ }
- /** @inheritdoc */
- public createAndSetupWorker (): Worker {
- const worker: Worker = this.createWorker()
+ /**
+ * Creates a new worker and sets it up completely in the pool worker nodes.
+ *
+ * @returns New, completely set up worker.
+ */
+ protected createAndSetupWorker (): Worker {
+ const worker = this.createWorker()
+ worker.on('message', this.opts.messageHandler ?? EMPTY_FUNCTION)
worker.on('error', this.opts.errorHandler ?? EMPTY_FUNCTION)
+ worker.on('error', error => {
+ if (this.emitter != null) {
+ this.emitter.emit(PoolEvents.error, error)
+ }
+ if (this.opts.enableTasksQueue === true) {
+ this.redistributeQueuedTasks(worker)
+ }
+ if (this.opts.restartWorkerOnError === true && !this.starting) {
+ if (this.getWorkerInfo(this.getWorkerNodeKey(worker)).dynamic) {
+ this.createAndSetupDynamicWorker()
+ } else {
+ this.createAndSetupWorker()
+ }
+ }
+ })
worker.on('online', this.opts.onlineHandler ?? EMPTY_FUNCTION)
worker.on('exit', this.opts.exitHandler ?? EMPTY_FUNCTION)
- worker.once('exit', () => this.removeWorker(worker))
-
- this.workers.push(worker)
+ worker.once('exit', () => {
+ this.removeWorkerNode(worker)
+ })
- // Init tasks map
- this.tasks.set(worker, 0)
+ this.pushWorkerNode(worker)
this.afterWorkerSetup(worker)
return worker
}
+ private redistributeQueuedTasks (worker: Worker): void {
+ const workerNodeKey = this.getWorkerNodeKey(worker)
+ while (this.tasksQueueSize(workerNodeKey) > 0) {
+ let targetWorkerNodeKey: number = workerNodeKey
+ let minQueuedTasks = Infinity
+ for (const [workerNodeId, workerNode] of this.workerNodes.entries()) {
+ if (
+ workerNodeId !== workerNodeKey &&
+ workerNode.usage.tasks.queued === 0
+ ) {
+ targetWorkerNodeKey = workerNodeId
+ break
+ }
+ if (
+ workerNodeId !== workerNodeKey &&
+ workerNode.usage.tasks.queued < minQueuedTasks
+ ) {
+ minQueuedTasks = workerNode.usage.tasks.queued
+ targetWorkerNodeKey = workerNodeId
+ }
+ }
+ this.enqueueTask(
+ targetWorkerNodeKey,
+ this.dequeueTask(workerNodeKey) as Task<Data>
+ )
+ }
+ }
+
/**
- * This function is the listener registered for each worker.
+ * Creates a new dynamic worker and sets it up completely in the pool worker nodes.
*
- * @returns The listener function to execute when a message is sent from a worker.
+ * @returns New, completely set up dynamic worker.
+ */
+ protected createAndSetupDynamicWorker (): Worker {
+ const worker = this.createAndSetupWorker()
+ this.registerWorkerMessageListener(worker, message => {
+ const workerNodeKey = this.getWorkerNodeKey(worker)
+ if (
+ isKillBehavior(KillBehaviors.HARD, message.kill) ||
+ (message.kill != null &&
+ ((this.opts.enableTasksQueue === false &&
+ this.workerNodes[workerNodeKey].usage.tasks.executing === 0) ||
+ (this.opts.enableTasksQueue === true &&
+ this.workerNodes[workerNodeKey].usage.tasks.executing === 0 &&
+ this.tasksQueueSize(workerNodeKey) === 0)))
+ ) {
+ // Kill message received from the worker: no new tasks are submitted to that worker for a while ( > maxInactiveTime)
+ void (this.destroyWorker(worker) as Promise<void>)
+ }
+ })
+ const workerInfo = this.getWorkerInfo(this.getWorkerNodeKey(worker))
+ workerInfo.dynamic = true
+ this.sendToWorker(worker, {
+ checkAlive: true,
+ workerId: workerInfo.id as number
+ })
+ return worker
+ }
+
+ /**
+ * This function is the listener registered for each worker message.
+ *
+ * @returns The listener function to execute when a message is received from a worker.
*/
protected workerListener (): (message: MessageValue<Response>) => void {
- const listener: (message: MessageValue<Response>) => void = message => {
- if (message.id) {
- const value = this.promiseMap.get(message.id)
- if (value) {
- this.decreaseWorkersTasks(value.worker)
- if (message.error) value.reject(message.error)
- else value.resolve(message.data as Response)
- this.promiseMap.delete(message.id)
+ return message => {
+ this.checkMessageWorkerId(message)
+ if (message.ready != null && message.workerId != null) {
+ // Worker ready message received
+ this.handleWorkerReadyMessage(message)
+ } else if (message.id != null) {
+ // Task execution response received
+ this.handleTaskExecutionResponse(message)
+ }
+ }
+ }
+
+ private handleWorkerReadyMessage (message: MessageValue<Response>): void {
+ const worker = this.getWorkerById(message.workerId)
+ this.getWorkerInfo(this.getWorkerNodeKey(worker as Worker)).ready =
+ message.ready as boolean
+ if (this.emitter != null && this.ready) {
+ this.emitter.emit(PoolEvents.ready, this.info)
+ }
+ }
+
+ private handleTaskExecutionResponse (message: MessageValue<Response>): void {
+ const promiseResponse = this.promiseResponseMap.get(message.id as string)
+ if (promiseResponse != null) {
+ if (message.taskError != null) {
+ if (this.emitter != null) {
+ this.emitter.emit(PoolEvents.taskError, message.taskError)
}
+ promiseResponse.reject(message.taskError.message)
+ } else {
+ promiseResponse.resolve(message.data as Response)
+ }
+ this.afterTaskExecutionHook(promiseResponse.worker, message)
+ this.promiseResponseMap.delete(message.id as string)
+ const workerNodeKey = this.getWorkerNodeKey(promiseResponse.worker)
+ if (
+ this.opts.enableTasksQueue === true &&
+ this.tasksQueueSize(workerNodeKey) > 0
+ ) {
+ this.executeTask(
+ workerNodeKey,
+ this.dequeueTask(workerNodeKey) as Task<Data>
+ )
}
+ this.workerChoiceStrategyContext.update(workerNodeKey)
}
- return listener
+ }
+
+ private checkAndEmitEvents (): void {
+ if (this.emitter != null) {
+ if (this.busy) {
+ this.emitter.emit(PoolEvents.busy, this.info)
+ }
+ if (this.type === PoolTypes.dynamic && this.full) {
+ this.emitter.emit(PoolEvents.full, this.info)
+ }
+ }
+ }
+
+ /**
+ * Gets the worker information.
+ *
+ * @param workerNodeKey - The worker node key.
+ */
+ private getWorkerInfo (workerNodeKey: number): WorkerInfo {
+ return this.workerNodes[workerNodeKey].info
+ }
+
+ /**
+ * Pushes the given worker in the pool worker nodes.
+ *
+ * @param worker - The worker.
+ * @returns The worker nodes length.
+ */
+ private pushWorkerNode (worker: Worker): number {
+ return this.workerNodes.push(new WorkerNode(worker, this.worker))
+ }
+
+ /**
+ * Removes the given worker from the pool worker nodes.
+ *
+ * @param worker - The worker.
+ */
+ private removeWorkerNode (worker: Worker): void {
+ const workerNodeKey = this.getWorkerNodeKey(worker)
+ if (workerNodeKey !== -1) {
+ this.workerNodes.splice(workerNodeKey, 1)
+ this.workerChoiceStrategyContext.remove(workerNodeKey)
+ }
+ }
+
+ private executeTask (workerNodeKey: number, task: Task<Data>): void {
+ this.beforeTaskExecutionHook(workerNodeKey, task)
+ this.sendToWorker(this.workerNodes[workerNodeKey].worker, task)
+ }
+
+ private enqueueTask (workerNodeKey: number, task: Task<Data>): number {
+ return this.workerNodes[workerNodeKey].enqueueTask(task)
+ }
+
+ private dequeueTask (workerNodeKey: number): Task<Data> | undefined {
+ return this.workerNodes[workerNodeKey].dequeueTask()
+ }
+
+ private tasksQueueSize (workerNodeKey: number): number {
+ return this.workerNodes[workerNodeKey].tasksQueueSize()
+ }
+
+ private flushTasksQueue (workerNodeKey: number): void {
+ while (this.tasksQueueSize(workerNodeKey) > 0) {
+ this.executeTask(
+ workerNodeKey,
+ this.dequeueTask(workerNodeKey) as Task<Data>
+ )
+ }
+ this.workerNodes[workerNodeKey].clearTasksQueue()
+ }
+
+ private flushTasksQueues (): void {
+ for (const [workerNodeKey] of this.workerNodes.entries()) {
+ this.flushTasksQueue(workerNodeKey)
+ }
+ }
+
+ private setWorkerStatistics (worker: Worker): void {
+ this.sendToWorker(worker, {
+ statistics: {
+ runTime:
+ this.workerChoiceStrategyContext.getTaskStatisticsRequirements()
+ .runTime.aggregate,
+ elu: this.workerChoiceStrategyContext.getTaskStatisticsRequirements()
+ .elu.aggregate
+ },
+ workerId: this.getWorkerInfo(this.getWorkerNodeKey(worker)).id as number
+ })
}
}