-import crypto from 'node:crypto'
-import type { MessageValue, PromiseResponseWrapper } from '../utility-types'
+import { randomUUID } from 'node:crypto'
+import { performance } from 'node:perf_hooks'
+import type { TransferListItem } from 'node:worker_threads'
+import { EventEmitterAsyncResource } from 'node:events'
+import type {
+ MessageValue,
+ PromiseResponseWrapper,
+ Task
+} from '../utility-types'
import {
+ DEFAULT_TASK_NAME,
DEFAULT_WORKER_CHOICE_STRATEGY_OPTIONS,
EMPTY_FUNCTION,
- median
+ average,
+ isKillBehavior,
+ isPlainObject,
+ max,
+ median,
+ min,
+ round
} from '../utils'
-import { KillBehaviors, isKillBehavior } from '../worker/worker-options'
-import { PoolEvents, type PoolOptions, type TasksQueueOptions } from './pool'
-import { PoolEmitter } from './pool'
-import type { IPoolInternal } from './pool-internal'
-import { PoolType } from './pool-internal'
-import type { IWorker, Task, TasksUsage, WorkerNode } from './worker'
+import { KillBehaviors } from '../worker/worker-options'
+import type { TaskFunction } from '../worker/task-functions'
import {
+ type IPool,
+ PoolEvents,
+ type PoolInfo,
+ type PoolOptions,
+ type PoolType,
+ PoolTypes,
+ type TasksQueueOptions
+} from './pool'
+import type {
+ IWorker,
+ IWorkerNode,
+ WorkerInfo,
+ WorkerNodeEventDetail,
+ WorkerType,
+ WorkerUsage
+} from './worker'
+import {
+ type MeasurementStatisticsRequirements,
+ Measurements,
WorkerChoiceStrategies,
- type WorkerChoiceStrategy
+ type WorkerChoiceStrategy,
+ type WorkerChoiceStrategyOptions
} from './selection-strategies/selection-strategies-types'
import { WorkerChoiceStrategyContext } from './selection-strategies/worker-choice-strategy-context'
-import { CircularArray } from '../circular-array'
+import { version } from './version'
+import { WorkerNode } from './worker-node'
+import {
+ checkFilePath,
+ checkValidTasksQueueOptions,
+ checkValidWorkerChoiceStrategy,
+ updateMeasurementStatistics
+} from './utils'
/**
* 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 serializable data.
- * @typeParam Response - Type of response of execution. This can only be serializable data.
+ * @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 abstract class AbstractPool<
Worker extends IWorker,
Data = unknown,
Response = unknown
-> implements IPoolInternal<Worker, Data, Response> {
+> implements IPool<Worker, Data, Response> {
/** @inheritDoc */
- public readonly workerNodes: Array<WorkerNode<Worker, Data>> = []
+ public readonly workerNodes: Array<IWorkerNode<Worker, Data>> = []
/** @inheritDoc */
- public readonly emitter?: PoolEmitter
+ public emitter?: EventEmitterAsyncResource
/**
- * The execution response promise map.
- *
+ * Dynamic pool maximum size property placeholder.
+ */
+ protected readonly max?: number
+
+ /**
+ * The task execution response promise map:
* - `key`: The message id of each submitted task.
* - `value`: An object that contains the worker, the execution response promise resolve and reject callbacks.
*
* When we receive a message from the worker, we get a map entry with the promise resolve/reject bound to the message id.
*/
- protected promiseResponseMap: Map<
- string,
- PromiseResponseWrapper<Worker, Response>
- > = new Map<string, PromiseResponseWrapper<Worker, Response>>()
+ protected promiseResponseMap: Map<string, PromiseResponseWrapper<Response>> =
+ new Map<string, PromiseResponseWrapper<Response>>()
/**
* Worker choice strategy context referencing a worker choice algorithm implementation.
- *
- * Default to a round robin algorithm.
*/
protected workerChoiceStrategyContext: WorkerChoiceStrategyContext<
Worker,
Response
>
+ /**
+ * The task functions added at runtime map:
+ * - `key`: The task function name.
+ * - `value`: The task function itself.
+ */
+ private readonly taskFunctions: Map<string, TaskFunction<Data, Response>>
+
+ /**
+ * Whether the pool is started or not.
+ */
+ private started: boolean
+ /**
+ * Whether the pool is starting or not.
+ */
+ private starting: boolean
+ /**
+ * The start timestamp of the pool.
+ */
+ private readonly startTimestamp
+
/**
* Constructs a new poolifier pool.
*
* @param numberOfWorkers - Number of workers that this pool should manage.
- * @param filePath - Path to the worker-file.
+ * @param filePath - Path to the worker file.
* @param opts - Options for the pool.
*/
public constructor (
- public readonly numberOfWorkers: number,
- public readonly filePath: string,
- public readonly opts: PoolOptions<Worker>
+ 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!')
+ throw new Error(
+ 'Cannot start a pool from a worker with the same type as the pool'
+ )
}
+ checkFilePath(this.filePath)
this.checkNumberOfWorkers(this.numberOfWorkers)
- this.checkFilePath(this.filePath)
this.checkPoolOptions(this.opts)
- this.chooseWorkerNode.bind(this)
- this.executeTask.bind(this)
- this.enqueueTask.bind(this)
- this.checkAndEmitEvents.bind(this)
-
- this.setupHook()
-
- for (let i = 1; i <= this.numberOfWorkers; i++) {
- this.createAndSetupWorker()
- }
+ this.chooseWorkerNode = this.chooseWorkerNode.bind(this)
+ this.executeTask = this.executeTask.bind(this)
+ this.enqueueTask = this.enqueueTask.bind(this)
if (this.opts.enableEvents === true) {
- this.emitter = new PoolEmitter()
+ this.initializeEventEmitter()
}
this.workerChoiceStrategyContext = new WorkerChoiceStrategyContext<
Worker,
this.opts.workerChoiceStrategy,
this.opts.workerChoiceStrategyOptions
)
- }
- 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')
+ this.setupHook()
+
+ this.taskFunctions = new Map<string, TaskFunction<Data, Response>>()
+
+ this.started = false
+ this.starting = false
+ if (this.opts.startWorkers === true) {
+ this.start()
}
+
+ this.startTimestamp = performance.now()
}
private checkNumberOfWorkers (numberOfWorkers: number): void {
)
} else if (!Number.isSafeInteger(numberOfWorkers)) {
throw new TypeError(
- 'Cannot instantiate a pool with a non integer number of workers'
+ '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 === PoolType.FIXED && numberOfWorkers === 0) {
- throw new Error('Cannot instantiate a fixed pool with no worker')
+ } else if (this.type === PoolTypes.fixed && numberOfWorkers === 0) {
+ throw new RangeError('Cannot instantiate a fixed pool with zero worker')
}
}
private checkPoolOptions (opts: PoolOptions<Worker>): void {
- this.opts.workerChoiceStrategy =
- opts.workerChoiceStrategy ?? WorkerChoiceStrategies.ROUND_ROBIN
- this.checkValidWorkerChoiceStrategy(this.opts.workerChoiceStrategy)
- this.opts.workerChoiceStrategyOptions =
- opts.workerChoiceStrategyOptions ?? DEFAULT_WORKER_CHOICE_STRATEGY_OPTIONS
- this.opts.enableEvents = opts.enableEvents ?? true
- this.opts.enableTasksQueue = opts.enableTasksQueue ?? false
- if (this.opts.enableTasksQueue) {
- if ((opts.tasksQueueOptions?.concurrency as number) <= 0) {
- throw new Error(
- `Invalid tasks queue concurrency '${
- (opts.tasksQueueOptions as TasksQueueOptions).concurrency as number
- }'`
- )
+ if (isPlainObject(opts)) {
+ this.opts.startWorkers = opts.startWorkers ?? true
+ checkValidWorkerChoiceStrategy(
+ opts.workerChoiceStrategy as WorkerChoiceStrategy
+ )
+ this.opts.workerChoiceStrategy =
+ opts.workerChoiceStrategy ?? WorkerChoiceStrategies.ROUND_ROBIN
+ this.checkValidWorkerChoiceStrategyOptions(
+ opts.workerChoiceStrategyOptions as WorkerChoiceStrategyOptions
+ )
+ this.opts.workerChoiceStrategyOptions = {
+ ...DEFAULT_WORKER_CHOICE_STRATEGY_OPTIONS,
+ ...opts.workerChoiceStrategyOptions
}
- this.opts.tasksQueueOptions = {
- concurrency: opts.tasksQueueOptions?.concurrency ?? 1
+ this.opts.restartWorkerOnError = opts.restartWorkerOnError ?? true
+ this.opts.enableEvents = opts.enableEvents ?? true
+ this.opts.enableTasksQueue = opts.enableTasksQueue ?? false
+ if (this.opts.enableTasksQueue) {
+ 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
+ private checkValidWorkerChoiceStrategyOptions (
+ workerChoiceStrategyOptions: WorkerChoiceStrategyOptions
): void {
- if (!Object.values(WorkerChoiceStrategies).includes(workerChoiceStrategy)) {
+ if (
+ workerChoiceStrategyOptions != null &&
+ !isPlainObject(workerChoiceStrategyOptions)
+ ) {
+ throw new TypeError(
+ 'Invalid worker choice strategy options: must be a plain object'
+ )
+ }
+ if (
+ workerChoiceStrategyOptions?.retries != null &&
+ !Number.isSafeInteger(workerChoiceStrategyOptions.retries)
+ ) {
+ throw new TypeError(
+ 'Invalid worker choice strategy options: retries must be an integer'
+ )
+ }
+ if (
+ workerChoiceStrategyOptions?.retries != null &&
+ workerChoiceStrategyOptions.retries < 0
+ ) {
+ throw new RangeError(
+ `Invalid worker choice strategy options: retries '${workerChoiceStrategyOptions.retries}' must be greater or equal than zero`
+ )
+ }
+ if (
+ workerChoiceStrategyOptions?.weights != null &&
+ Object.keys(workerChoiceStrategyOptions.weights).length !== this.maxSize
+ ) {
throw new Error(
- `Invalid worker choice strategy '${workerChoiceStrategy}'`
+ 'Invalid worker choice strategy options: must have a weight for each worker node'
)
}
+ if (
+ workerChoiceStrategyOptions?.measurement != null &&
+ !Object.values(Measurements).includes(
+ workerChoiceStrategyOptions.measurement
+ )
+ ) {
+ throw new Error(
+ `Invalid worker choice strategy options: invalid measurement '${workerChoiceStrategyOptions.measurement}'`
+ )
+ }
+ }
+
+ private initializeEventEmitter (): void {
+ this.emitter = new EventEmitterAsyncResource({
+ name: `poolifier:${this.type}-${this.worker}-pool`
+ })
}
/** @inheritDoc */
- public abstract get type (): PoolType
+ public get info (): PoolInfo {
+ return {
+ version,
+ type: this.type,
+ worker: this.worker,
+ started: this.started,
+ 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
+ ),
+ ...(this.opts.enableTasksQueue === true && {
+ queuedTasks: this.workerNodes.reduce(
+ (accumulator, workerNode) =>
+ accumulator + workerNode.usage.tasks.queued,
+ 0
+ )
+ }),
+ ...(this.opts.enableTasksQueue === true && {
+ maxQueuedTasks: this.workerNodes.reduce(
+ (accumulator, workerNode) =>
+ accumulator + (workerNode.usage.tasks?.maxQueued ?? 0),
+ 0
+ )
+ }),
+ ...(this.opts.enableTasksQueue === true && {
+ backPressure: this.hasBackPressure()
+ }),
+ ...(this.opts.enableTasksQueue === true && {
+ stolenTasks: this.workerNodes.reduce(
+ (accumulator, workerNode) =>
+ accumulator + workerNode.usage.tasks.stolen,
+ 0
+ )
+ }),
+ failedTasks: this.workerNodes.reduce(
+ (accumulator, workerNode) =>
+ accumulator + workerNode.usage.tasks.failed,
+ 0
+ ),
+ ...(this.workerChoiceStrategyContext.getTaskStatisticsRequirements()
+ .runTime.aggregate && {
+ runTime: {
+ minimum: round(
+ min(
+ ...this.workerNodes.map(
+ workerNode => workerNode.usage.runTime?.minimum ?? Infinity
+ )
+ )
+ ),
+ maximum: round(
+ max(
+ ...this.workerNodes.map(
+ workerNode => workerNode.usage.runTime?.maximum ?? -Infinity
+ )
+ )
+ ),
+ ...(this.workerChoiceStrategyContext.getTaskStatisticsRequirements()
+ .runTime.average && {
+ average: round(
+ average(
+ this.workerNodes.reduce<number[]>(
+ (accumulator, workerNode) =>
+ accumulator.concat(workerNode.usage.runTime.history),
+ []
+ )
+ )
+ )
+ }),
+ ...(this.workerChoiceStrategyContext.getTaskStatisticsRequirements()
+ .runTime.median && {
+ median: round(
+ median(
+ this.workerNodes.reduce<number[]>(
+ (accumulator, workerNode) =>
+ accumulator.concat(workerNode.usage.runTime.history),
+ []
+ )
+ )
+ )
+ })
+ }
+ }),
+ ...(this.workerChoiceStrategyContext.getTaskStatisticsRequirements()
+ .waitTime.aggregate && {
+ waitTime: {
+ minimum: round(
+ min(
+ ...this.workerNodes.map(
+ workerNode => workerNode.usage.waitTime?.minimum ?? Infinity
+ )
+ )
+ ),
+ maximum: round(
+ max(
+ ...this.workerNodes.map(
+ workerNode => workerNode.usage.waitTime?.maximum ?? -Infinity
+ )
+ )
+ ),
+ ...(this.workerChoiceStrategyContext.getTaskStatisticsRequirements()
+ .waitTime.average && {
+ average: round(
+ average(
+ this.workerNodes.reduce<number[]>(
+ (accumulator, workerNode) =>
+ accumulator.concat(workerNode.usage.waitTime.history),
+ []
+ )
+ )
+ )
+ }),
+ ...(this.workerChoiceStrategyContext.getTaskStatisticsRequirements()
+ .waitTime.median && {
+ median: round(
+ median(
+ this.workerNodes.reduce<number[]>(
+ (accumulator, workerNode) =>
+ accumulator.concat(workerNode.usage.waitTime.history),
+ []
+ )
+ )
+ )
+ })
+ }
+ })
+ }
+ }
/**
- * Number of tasks running in the pool.
+ * The pool readiness boolean status.
*/
- private get numberOfRunningTasks (): number {
- return this.workerNodes.reduce(
- (accumulator, workerNode) => accumulator + workerNode.tasksUsage.running,
- 0
+ private get ready (): boolean {
+ return (
+ this.workerNodes.reduce(
+ (accumulator, workerNode) =>
+ !workerNode.info.dynamic && workerNode.info.ready
+ ? accumulator + 1
+ : accumulator,
+ 0
+ ) >= this.minSize
)
}
/**
- * Number of tasks queued in the pool.
+ * The approximate pool utilization.
+ *
+ * @returns The pool utilization.
*/
- private get numberOfQueuedTasks (): number {
- if (this.opts.enableTasksQueue === false) {
- return 0
- }
- return this.workerNodes.reduce(
- (accumulator, workerNode) => accumulator + workerNode.tasksQueue.length,
+ private get utilization (): number {
+ const poolTimeCapacity =
+ (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) / poolTimeCapacity
+ }
+
+ /**
+ * The pool type.
+ *
+ * If it is `'dynamic'`, it provides the `max` property.
+ */
+ protected abstract get type (): PoolType
+
+ /**
+ * The worker type.
+ */
+ protected abstract get worker (): WorkerType
+
+ /**
+ * The pool minimum size.
+ */
+ protected get minSize (): number {
+ return this.numberOfWorkers
+ }
+
+ /**
+ * The pool maximum size.
+ */
+ protected get maxSize (): number {
+ return this.max ?? this.numberOfWorkers
+ }
+
+ /**
+ * Checks if the worker id sent in the received message from a worker is valid.
+ *
+ * @param message - The received message.
+ * @throws {@link https://nodejs.org/api/errors.html#class-error} If the worker id is invalid.
+ */
+ private checkMessageWorkerId (message: MessageValue<Data | Response>): void {
+ if (message.workerId == null) {
+ throw new Error('Worker message received without worker id')
+ } else if (this.getWorkerNodeKeyByWorkerId(message.workerId) === -1) {
+ throw new Error(
+ `Worker message received from unknown worker '${message.workerId}'`
+ )
+ }
}
/**
* Gets the given worker its worker node key.
*
* @param worker - The worker.
- * @returns The worker node key if the worker is found in the pool worker nodes, `-1` otherwise.
+ * @returns The worker node key if found in the pool worker nodes, `-1` otherwise.
*/
- private getWorkerNodeKey (worker: Worker): number {
+ private getWorkerNodeKeyByWorker (worker: Worker): number {
return this.workerNodes.findIndex(
workerNode => workerNode.worker === worker
)
}
+ /**
+ * Gets the worker node key given its worker id.
+ *
+ * @param workerId - The worker id.
+ * @returns The worker node key if the worker id is found in the pool worker nodes, `-1` otherwise.
+ */
+ private getWorkerNodeKeyByWorkerId (workerId: number | undefined): number {
+ return this.workerNodes.findIndex(
+ workerNode => workerNode.info.id === workerId
+ )
+ }
+
/** @inheritDoc */
public setWorkerChoiceStrategy (
- workerChoiceStrategy: WorkerChoiceStrategy
+ workerChoiceStrategy: WorkerChoiceStrategy,
+ workerChoiceStrategyOptions?: WorkerChoiceStrategyOptions
): void {
- this.checkValidWorkerChoiceStrategy(workerChoiceStrategy)
+ checkValidWorkerChoiceStrategy(workerChoiceStrategy)
this.opts.workerChoiceStrategy = workerChoiceStrategy
- for (const workerNode of this.workerNodes) {
- this.setWorkerNodeTasksUsage(workerNode, {
- run: 0,
- running: 0,
- runTime: 0,
- runTimeHistory: new CircularArray(),
- avgRunTime: 0,
- medRunTime: 0,
- error: 0
- })
- }
this.workerChoiceStrategyContext.setWorkerChoiceStrategy(
- workerChoiceStrategy
+ this.opts.workerChoiceStrategy
+ )
+ if (workerChoiceStrategyOptions != null) {
+ this.setWorkerChoiceStrategyOptions(workerChoiceStrategyOptions)
+ }
+ for (const [workerNodeKey, workerNode] of this.workerNodes.entries()) {
+ workerNode.resetUsage()
+ this.sendStatisticsMessageToWorker(workerNodeKey)
+ }
+ }
+
+ /** @inheritDoc */
+ public setWorkerChoiceStrategyOptions (
+ workerChoiceStrategyOptions: WorkerChoiceStrategyOptions
+ ): void {
+ this.checkValidWorkerChoiceStrategyOptions(workerChoiceStrategyOptions)
+ this.opts.workerChoiceStrategyOptions = {
+ ...DEFAULT_WORKER_CHOICE_STRATEGY_OPTIONS,
+ ...workerChoiceStrategyOptions
+ }
+ this.workerChoiceStrategyContext.setOptions(
+ this.opts.workerChoiceStrategyOptions
)
}
/** @inheritDoc */
- public abstract get full (): boolean
+ public enableTasksQueue (
+ enable: boolean,
+ tasksQueueOptions?: TasksQueueOptions
+ ): void {
+ if (this.opts.enableTasksQueue === true && !enable) {
+ this.unsetTaskStealing()
+ this.unsetTasksStealingOnBackPressure()
+ this.flushTasksQueues()
+ }
+ this.opts.enableTasksQueue = enable
+ this.setTasksQueueOptions(tasksQueueOptions as TasksQueueOptions)
+ }
/** @inheritDoc */
- public abstract get busy (): boolean
+ public setTasksQueueOptions (tasksQueueOptions: TasksQueueOptions): void {
+ if (this.opts.enableTasksQueue === true) {
+ checkValidTasksQueueOptions(tasksQueueOptions)
+ this.opts.tasksQueueOptions =
+ this.buildTasksQueueOptions(tasksQueueOptions)
+ this.setTasksQueueSize(this.opts.tasksQueueOptions.size as number)
+ if (this.opts.tasksQueueOptions.taskStealing === true) {
+ this.setTaskStealing()
+ } else {
+ this.unsetTaskStealing()
+ }
+ if (this.opts.tasksQueueOptions.tasksStealingOnBackPressure === true) {
+ this.setTasksStealingOnBackPressure()
+ } else {
+ this.unsetTasksStealingOnBackPressure()
+ }
+ } else if (this.opts.tasksQueueOptions != null) {
+ delete this.opts.tasksQueueOptions
+ }
+ }
+
+ private buildTasksQueueOptions (
+ tasksQueueOptions: TasksQueueOptions
+ ): TasksQueueOptions {
+ return {
+ ...{
+ size: Math.pow(this.maxSize, 2),
+ concurrency: 1,
+ taskStealing: true,
+ tasksStealingOnBackPressure: true
+ },
+ ...tasksQueueOptions
+ }
+ }
+
+ private setTasksQueueSize (size: number): void {
+ for (const workerNode of this.workerNodes) {
+ workerNode.tasksQueueBackPressureSize = size
+ }
+ }
+
+ private setTaskStealing (): void {
+ for (const [workerNodeKey] of this.workerNodes.entries()) {
+ this.workerNodes[workerNodeKey].addEventListener(
+ 'emptyqueue',
+ this.handleEmptyQueueEvent as EventListener
+ )
+ }
+ }
+
+ private unsetTaskStealing (): void {
+ for (const [workerNodeKey] of this.workerNodes.entries()) {
+ this.workerNodes[workerNodeKey].removeEventListener(
+ 'emptyqueue',
+ this.handleEmptyQueueEvent as EventListener
+ )
+ }
+ }
+
+ private setTasksStealingOnBackPressure (): void {
+ for (const [workerNodeKey] of this.workerNodes.entries()) {
+ this.workerNodes[workerNodeKey].addEventListener(
+ 'backpressure',
+ this.handleBackPressureEvent as EventListener
+ )
+ }
+ }
+ private unsetTasksStealingOnBackPressure (): void {
+ for (const [workerNodeKey] of this.workerNodes.entries()) {
+ this.workerNodes[workerNodeKey].removeEventListener(
+ 'backpressure',
+ this.handleBackPressureEvent as EventListener
+ )
+ }
+ }
+
+ /**
+ * 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 concurrently their tasks quota or not.
+ *
+ * @returns Worker nodes busyness boolean status.
+ */
protected internalBusy (): boolean {
- return this.findFreeWorkerNodeKey() === -1
+ if (this.opts.enableTasksQueue === true) {
+ return (
+ this.workerNodes.findIndex(
+ workerNode =>
+ workerNode.info.ready &&
+ workerNode.usage.tasks.executing <
+ (this.opts.tasksQueueOptions?.concurrency as number)
+ ) === -1
+ )
+ }
+ return (
+ this.workerNodes.findIndex(
+ workerNode =>
+ workerNode.info.ready && workerNode.usage.tasks.executing === 0
+ ) === -1
+ )
+ }
+
+ private async sendTaskFunctionOperationToWorker (
+ workerNodeKey: number,
+ message: MessageValue<Data>
+ ): Promise<boolean> {
+ return await new Promise<boolean>((resolve, reject) => {
+ const taskFunctionOperationListener = (
+ message: MessageValue<Response>
+ ): void => {
+ this.checkMessageWorkerId(message)
+ const workerId = this.getWorkerInfo(workerNodeKey).id as number
+ if (
+ message.taskFunctionOperationStatus != null &&
+ message.workerId === workerId
+ ) {
+ if (message.taskFunctionOperationStatus) {
+ resolve(true)
+ } else if (!message.taskFunctionOperationStatus) {
+ reject(
+ new Error(
+ `Task function operation '${
+ message.taskFunctionOperation as string
+ }' failed on worker ${message.workerId} with error: '${
+ message.workerError?.message as string
+ }'`
+ )
+ )
+ }
+ this.deregisterWorkerMessageListener(
+ this.getWorkerNodeKeyByWorkerId(message.workerId),
+ taskFunctionOperationListener
+ )
+ }
+ }
+ this.registerWorkerMessageListener(
+ workerNodeKey,
+ taskFunctionOperationListener
+ )
+ this.sendToWorker(workerNodeKey, message)
+ })
+ }
+
+ private async sendTaskFunctionOperationToWorkers (
+ message: MessageValue<Data>
+ ): Promise<boolean> {
+ return await new Promise<boolean>((resolve, reject) => {
+ const responsesReceived = new Array<MessageValue<Response>>()
+ const taskFunctionOperationsListener = (
+ message: MessageValue<Response>
+ ): void => {
+ this.checkMessageWorkerId(message)
+ if (message.taskFunctionOperationStatus != null) {
+ responsesReceived.push(message)
+ if (responsesReceived.length === this.workerNodes.length) {
+ if (
+ responsesReceived.every(
+ message => message.taskFunctionOperationStatus === true
+ )
+ ) {
+ resolve(true)
+ } else if (
+ responsesReceived.some(
+ message => message.taskFunctionOperationStatus === false
+ )
+ ) {
+ const errorResponse = responsesReceived.find(
+ response => response.taskFunctionOperationStatus === false
+ )
+ reject(
+ new Error(
+ `Task function operation '${
+ message.taskFunctionOperation as string
+ }' failed on worker ${
+ errorResponse?.workerId as number
+ } with error: '${
+ errorResponse?.workerError?.message as string
+ }'`
+ )
+ )
+ }
+ this.deregisterWorkerMessageListener(
+ this.getWorkerNodeKeyByWorkerId(message.workerId),
+ taskFunctionOperationsListener
+ )
+ }
+ }
+ }
+ for (const [workerNodeKey] of this.workerNodes.entries()) {
+ this.registerWorkerMessageListener(
+ workerNodeKey,
+ taskFunctionOperationsListener
+ )
+ this.sendToWorker(workerNodeKey, message)
+ }
+ })
+ }
+
+ /** @inheritDoc */
+ public hasTaskFunction (name: string): boolean {
+ for (const workerNode of this.workerNodes) {
+ if (
+ Array.isArray(workerNode.info.taskFunctionNames) &&
+ workerNode.info.taskFunctionNames.includes(name)
+ ) {
+ return true
+ }
+ }
+ return false
+ }
+
+ /** @inheritDoc */
+ public async addTaskFunction (
+ name: string,
+ fn: TaskFunction<Data, Response>
+ ): Promise<boolean> {
+ if (typeof name !== 'string') {
+ throw new TypeError('name argument must be a string')
+ }
+ if (typeof name === 'string' && name.trim().length === 0) {
+ throw new TypeError('name argument must not be an empty string')
+ }
+ if (typeof fn !== 'function') {
+ throw new TypeError('fn argument must be a function')
+ }
+ const opResult = await this.sendTaskFunctionOperationToWorkers({
+ taskFunctionOperation: 'add',
+ taskFunctionName: name,
+ taskFunction: fn.toString()
+ })
+ this.taskFunctions.set(name, fn)
+ return opResult
+ }
+
+ /** @inheritDoc */
+ public async removeTaskFunction (name: string): Promise<boolean> {
+ if (!this.taskFunctions.has(name)) {
+ throw new Error(
+ 'Cannot remove a task function not handled on the pool side'
+ )
+ }
+ const opResult = await this.sendTaskFunctionOperationToWorkers({
+ taskFunctionOperation: 'remove',
+ taskFunctionName: name
+ })
+ this.deleteTaskFunctionWorkerUsages(name)
+ this.taskFunctions.delete(name)
+ return opResult
}
/** @inheritDoc */
- public findFreeWorkerNodeKey (): number {
- return this.workerNodes.findIndex(workerNode => {
- return workerNode.tasksUsage?.running === 0
+ public listTaskFunctionNames (): string[] {
+ for (const workerNode of this.workerNodes) {
+ if (
+ Array.isArray(workerNode.info.taskFunctionNames) &&
+ workerNode.info.taskFunctionNames.length > 0
+ ) {
+ return workerNode.info.taskFunctionNames
+ }
+ }
+ return []
+ }
+
+ /** @inheritDoc */
+ public async setDefaultTaskFunction (name: string): Promise<boolean> {
+ return await this.sendTaskFunctionOperationToWorkers({
+ taskFunctionOperation: 'default',
+ taskFunctionName: name
})
}
+ private deleteTaskFunctionWorkerUsages (name: string): void {
+ for (const workerNode of this.workerNodes) {
+ workerNode.deleteTaskFunctionWorkerUsage(name)
+ }
+ }
+
+ private shallExecuteTask (workerNodeKey: number): boolean {
+ return (
+ this.tasksQueueSize(workerNodeKey) === 0 &&
+ this.workerNodes[workerNodeKey].usage.tasks.executing <
+ (this.opts.tasksQueueOptions?.concurrency as number)
+ )
+ }
+
/** @inheritDoc */
- public async execute (data: Data): Promise<Response> {
- const [workerNodeKey, workerNode] = this.chooseWorkerNode()
- const submittedTask: Task<Data> = {
- // eslint-disable-next-line @typescript-eslint/consistent-type-assertions
- data: data ?? ({} as Data),
- id: crypto.randomUUID()
- }
- const res = new Promise<Response>((resolve, reject) => {
- this.promiseResponseMap.set(submittedTask.id, {
+ public async execute (
+ data?: Data,
+ name?: string,
+ transferList?: TransferListItem[]
+ ): Promise<Response> {
+ return await new Promise<Response>((resolve, reject) => {
+ if (!this.started) {
+ reject(new Error('Cannot execute a task on not started pool'))
+ return
+ }
+ if (name != null && typeof name !== 'string') {
+ reject(new TypeError('name argument must be a string'))
+ return
+ }
+ if (
+ name != null &&
+ typeof name === 'string' &&
+ name.trim().length === 0
+ ) {
+ reject(new TypeError('name argument must not be an empty string'))
+ return
+ }
+ if (transferList != null && !Array.isArray(transferList)) {
+ reject(new TypeError('transferList argument must be an array'))
+ return
+ }
+ const timestamp = performance.now()
+ const workerNodeKey = this.chooseWorkerNode()
+ const task: Task<Data> = {
+ name: name ?? DEFAULT_TASK_NAME,
+ // eslint-disable-next-line @typescript-eslint/consistent-type-assertions
+ data: data ?? ({} as Data),
+ transferList,
+ timestamp,
+ taskId: randomUUID()
+ }
+ this.promiseResponseMap.set(task.taskId as string, {
resolve,
reject,
- worker: workerNode.worker
+ workerNodeKey
})
+ if (
+ this.opts.enableTasksQueue === false ||
+ (this.opts.enableTasksQueue === true &&
+ this.shallExecuteTask(workerNodeKey))
+ ) {
+ this.executeTask(workerNodeKey, task)
+ } else {
+ this.enqueueTask(workerNodeKey, task)
+ }
})
- if (
- this.opts.enableTasksQueue === true &&
- (this.busy ||
- this.workerNodes[workerNodeKey].tasksUsage.running >
- ((this.opts.tasksQueueOptions as TasksQueueOptions)
- .concurrency as number) -
- 1)
+ }
+
+ /** @inheritdoc */
+ public start (): void {
+ this.starting = true
+ while (
+ this.workerNodes.reduce(
+ (accumulator, workerNode) =>
+ !workerNode.info.dynamic ? accumulator + 1 : accumulator,
+ 0
+ ) < this.numberOfWorkers
) {
- this.enqueueTask(workerNodeKey, submittedTask)
- } else {
- this.executeTask(workerNodeKey, submittedTask)
+ this.createAndSetupWorkerNode()
}
- this.checkAndEmitEvents()
- // eslint-disable-next-line @typescript-eslint/return-await
- return res
+ this.starting = false
+ this.started = true
}
/** @inheritDoc */
public async destroy (): Promise<void> {
await Promise.all(
- this.workerNodes.map(async (workerNode, workerNodeKey) => {
- this.flushTasksQueue(workerNodeKey)
- await this.destroyWorker(workerNode.worker)
+ this.workerNodes.map(async (_, workerNodeKey) => {
+ await this.destroyWorkerNode(workerNodeKey)
})
)
+ this.emitter?.emit(PoolEvents.destroy, this.info)
+ this.emitter?.emitDestroy()
+ this.started = false
+ }
+
+ protected async sendKillMessageToWorker (
+ workerNodeKey: number
+ ): Promise<void> {
+ await new Promise<void>((resolve, reject) => {
+ const killMessageListener = (message: MessageValue<Response>): void => {
+ this.checkMessageWorkerId(message)
+ if (message.kill === 'success') {
+ resolve()
+ } else if (message.kill === 'failure') {
+ reject(
+ new Error(
+ `Kill message handling failed on worker ${
+ message.workerId as number
+ }`
+ )
+ )
+ }
+ }
+ this.registerWorkerMessageListener(workerNodeKey, killMessageListener)
+ this.sendToWorker(workerNodeKey, { kill: true })
+ })
}
/**
- * Shutdowns the given worker.
+ * Terminates the worker node given its worker node key.
*
- * @param worker - A worker within `workerNodes`.
+ * @param workerNodeKey - The worker node key.
*/
- protected abstract destroyWorker (worker: Worker): void | Promise<void>
+ protected abstract destroyWorkerNode (workerNodeKey: number): Promise<void>
/**
- * Setup hook to execute code before worker node are created in the abstract constructor.
- * Can be overridden
+ * Setup hook to execute code before worker nodes are created in the abstract constructor.
+ * Can be overridden.
*
* @virtual
*/
protected setupHook (): void {
- // Intentionally empty
+ /* Intentionally empty */
}
/**
* Can be overridden.
*
* @param workerNodeKey - The worker node key.
+ * @param task - The task to execute.
*/
- protected beforeTaskExecutionHook (workerNodeKey: number): void {
- ++this.workerNodes[workerNodeKey].tasksUsage.running
+ protected beforeTaskExecutionHook (
+ workerNodeKey: number,
+ task: Task<Data>
+ ): void {
+ if (this.workerNodes[workerNodeKey]?.usage != null) {
+ const workerUsage = this.workerNodes[workerNodeKey].usage
+ ++workerUsage.tasks.executing
+ this.updateWaitTimeWorkerUsage(workerUsage, task)
+ }
+ if (
+ this.shallUpdateTaskFunctionWorkerUsage(workerNodeKey) &&
+ this.workerNodes[workerNodeKey].getTaskFunctionWorkerUsage(
+ task.name as string
+ ) != null
+ ) {
+ const taskFunctionWorkerUsage = this.workerNodes[
+ workerNodeKey
+ ].getTaskFunctionWorkerUsage(task.name as string) as WorkerUsage
+ ++taskFunctionWorkerUsage.tasks.executing
+ this.updateWaitTimeWorkerUsage(taskFunctionWorkerUsage, task)
+ }
}
/**
* Hook executed after the worker task execution.
* Can be overridden.
*
- * @param worker - The worker.
+ * @param workerNodeKey - The worker node key.
* @param message - The received message.
*/
protected afterTaskExecutionHook (
- worker: Worker,
+ workerNodeKey: number,
message: MessageValue<Response>
): void {
- const workerTasksUsage = this.getWorkerTasksUsage(worker) as TasksUsage
- --workerTasksUsage.running
- ++workerTasksUsage.run
- if (message.error != null) {
- ++workerTasksUsage.error
- }
- if (this.workerChoiceStrategyContext.getRequiredStatistics().runTime) {
- workerTasksUsage.runTime += message.runTime ?? 0
- if (
- this.workerChoiceStrategyContext.getRequiredStatistics().avgRunTime &&
- workerTasksUsage.run !== 0
- ) {
- workerTasksUsage.avgRunTime =
- workerTasksUsage.runTime / workerTasksUsage.run
- }
- if (this.workerChoiceStrategyContext.getRequiredStatistics().medRunTime) {
- workerTasksUsage.runTimeHistory.push(message.runTime ?? 0)
- workerTasksUsage.medRunTime = median(workerTasksUsage.runTimeHistory)
- }
+ if (this.workerNodes[workerNodeKey]?.usage != null) {
+ const workerUsage = this.workerNodes[workerNodeKey].usage
+ this.updateTaskStatisticsWorkerUsage(workerUsage, message)
+ this.updateRunTimeWorkerUsage(workerUsage, message)
+ this.updateEluWorkerUsage(workerUsage, message)
+ }
+ if (
+ this.shallUpdateTaskFunctionWorkerUsage(workerNodeKey) &&
+ this.workerNodes[workerNodeKey].getTaskFunctionWorkerUsage(
+ message.taskPerformance?.name as string
+ ) != null
+ ) {
+ const taskFunctionWorkerUsage = this.workerNodes[
+ workerNodeKey
+ ].getTaskFunctionWorkerUsage(
+ message.taskPerformance?.name as string
+ ) as WorkerUsage
+ this.updateTaskStatisticsWorkerUsage(taskFunctionWorkerUsage, message)
+ this.updateRunTimeWorkerUsage(taskFunctionWorkerUsage, message)
+ this.updateEluWorkerUsage(taskFunctionWorkerUsage, message)
}
}
/**
- * Chooses a worker node for the next task.
- *
- * The default uses a round robin algorithm to distribute the load.
+ * Whether the worker node shall update its task function worker usage or not.
*
- * @returns [worker node key, worker node].
+ * @param workerNodeKey - The worker node key.
+ * @returns `true` if the worker node shall update its task function worker usage, `false` otherwise.
*/
- protected chooseWorkerNode (): [number, WorkerNode<Worker, Data>] {
- let workerNodeKey: number
- if (this.type === PoolType.DYNAMIC && !this.full && this.internalBusy()) {
- const workerCreated = this.createAndSetupWorker()
- this.registerWorkerMessageListener(workerCreated, message => {
- if (
- isKillBehavior(KillBehaviors.HARD, message.kill) ||
- (message.kill != null &&
- this.getWorkerTasksUsage(workerCreated)?.running === 0)
- ) {
- // Kill message received from the worker: no new tasks are submitted to that worker for a while ( > maxInactiveTime)
- this.flushTasksQueueByWorker(workerCreated)
- void this.destroyWorker(workerCreated)
- }
- })
- workerNodeKey = this.getWorkerNodeKey(workerCreated)
+ private shallUpdateTaskFunctionWorkerUsage (workerNodeKey: number): boolean {
+ const workerInfo = this.getWorkerInfo(workerNodeKey)
+ return (
+ workerInfo != null &&
+ Array.isArray(workerInfo.taskFunctionNames) &&
+ workerInfo.taskFunctionNames.length > 2
+ )
+ }
+
+ private updateTaskStatisticsWorkerUsage (
+ workerUsage: WorkerUsage,
+ message: MessageValue<Response>
+ ): void {
+ const workerTaskStatistics = workerUsage.tasks
+ if (
+ workerTaskStatistics.executing != null &&
+ workerTaskStatistics.executing > 0
+ ) {
+ --workerTaskStatistics.executing
+ }
+ if (message.workerError == null) {
+ ++workerTaskStatistics.executed
} else {
- workerNodeKey = this.workerChoiceStrategyContext.execute()
+ ++workerTaskStatistics.failed
+ }
+ }
+
+ private updateRunTimeWorkerUsage (
+ workerUsage: WorkerUsage,
+ message: MessageValue<Response>
+ ): void {
+ if (message.workerError != null) {
+ return
+ }
+ updateMeasurementStatistics(
+ workerUsage.runTime,
+ this.workerChoiceStrategyContext.getTaskStatisticsRequirements().runTime,
+ message.taskPerformance?.runTime ?? 0
+ )
+ }
+
+ private updateWaitTimeWorkerUsage (
+ workerUsage: WorkerUsage,
+ task: Task<Data>
+ ): void {
+ const timestamp = performance.now()
+ const taskWaitTime = timestamp - (task.timestamp ?? timestamp)
+ updateMeasurementStatistics(
+ workerUsage.waitTime,
+ this.workerChoiceStrategyContext.getTaskStatisticsRequirements().waitTime,
+ taskWaitTime
+ )
+ }
+
+ private updateEluWorkerUsage (
+ workerUsage: WorkerUsage,
+ message: MessageValue<Response>
+ ): void {
+ if (message.workerError != null) {
+ return
+ }
+ const eluTaskStatisticsRequirements: MeasurementStatisticsRequirements =
+ this.workerChoiceStrategyContext.getTaskStatisticsRequirements().elu
+ updateMeasurementStatistics(
+ workerUsage.elu.active,
+ eluTaskStatisticsRequirements,
+ message.taskPerformance?.elu?.active ?? 0
+ )
+ updateMeasurementStatistics(
+ workerUsage.elu.idle,
+ eluTaskStatisticsRequirements,
+ message.taskPerformance?.elu?.idle ?? 0
+ )
+ if (eluTaskStatisticsRequirements.aggregate) {
+ if (message.taskPerformance?.elu != null) {
+ if (workerUsage.elu.utilization != null) {
+ workerUsage.elu.utilization =
+ (workerUsage.elu.utilization +
+ message.taskPerformance.elu.utilization) /
+ 2
+ } else {
+ workerUsage.elu.utilization = message.taskPerformance.elu.utilization
+ }
+ }
}
- return [workerNodeKey, this.workerNodes[workerNodeKey]]
}
/**
- * Sends a message to the given worker.
+ * Chooses a worker node for the next task.
*
- * @param worker - The worker which should receive the message.
- * @param message - The message.
+ * The default worker choice strategy uses a round robin algorithm to distribute the tasks.
+ *
+ * @returns The chosen worker node key
*/
- protected abstract sendToWorker (
- worker: Worker,
- message: MessageValue<Data>
- ): void
+ private chooseWorkerNode (): number {
+ if (this.shallCreateDynamicWorker()) {
+ const workerNodeKey = this.createAndSetupDynamicWorkerNode()
+ if (
+ this.workerChoiceStrategyContext.getStrategyPolicy().dynamicWorkerUsage
+ ) {
+ return workerNodeKey
+ }
+ }
+ return this.workerChoiceStrategyContext.execute()
+ }
/**
- * Registers a listener callback on the given worker.
+ * Conditions for dynamic worker creation.
*
- * @param worker - The worker which should register a listener.
- * @param listener - The message listener callback.
+ * @returns Whether to create a dynamic worker or not.
*/
- protected abstract registerWorkerMessageListener<
- Message extends Data | Response
- >(worker: Worker, listener: (message: MessageValue<Message>) => void): void
+ private shallCreateDynamicWorker (): boolean {
+ return this.type === PoolTypes.dynamic && !this.full && this.internalBusy()
+ }
/**
- * Returns a newly created worker.
+ * Sends a message to worker given its worker node key.
+ *
+ * @param workerNodeKey - The worker node key.
+ * @param message - The message.
+ * @param transferList - The optional array of transferable objects.
*/
- protected abstract createWorker (): Worker
+ protected abstract sendToWorker (
+ workerNodeKey: number,
+ message: MessageValue<Data>,
+ transferList?: TransferListItem[]
+ ): void
/**
- * Function that can be hooked up when a worker has been newly created and moved to the pool worker nodes.
- *
- * Can be used to update the `maxListeners` or binding the `main-worker`\<-\>`worker` connection if not bind by default.
+ * Creates a new worker.
*
- * @param worker - The newly created worker.
+ * @returns Newly created worker.
*/
- protected abstract afterWorkerSetup (worker: Worker): void
+ protected abstract createWorker (): Worker
/**
- * Creates a new worker and sets it up completely in the pool worker nodes.
+ * Creates a new, completely set up worker node.
*
- * @returns New, completely set up worker.
+ * @returns New, completely set up worker node key.
*/
- protected createAndSetupWorker (): Worker {
+ protected createAndSetupWorkerNode (): number {
const worker = this.createWorker()
+ worker.on('online', this.opts.onlineHandler ?? EMPTY_FUNCTION)
worker.on('message', this.opts.messageHandler ?? EMPTY_FUNCTION)
worker.on('error', this.opts.errorHandler ?? EMPTY_FUNCTION)
- worker.on('online', this.opts.onlineHandler ?? EMPTY_FUNCTION)
+ worker.on('error', error => {
+ const workerNodeKey = this.getWorkerNodeKeyByWorker(worker)
+ const workerInfo = this.getWorkerInfo(workerNodeKey)
+ workerInfo.ready = false
+ this.emitter?.emit(PoolEvents.error, error)
+ this.workerNodes[workerNodeKey].closeChannel()
+ if (
+ this.started &&
+ !this.starting &&
+ this.opts.restartWorkerOnError === true
+ ) {
+ if (workerInfo.dynamic) {
+ this.createAndSetupDynamicWorkerNode()
+ } else {
+ this.createAndSetupWorkerNode()
+ }
+ }
+ if (this.started && this.opts.enableTasksQueue === true) {
+ this.redistributeQueuedTasks(workerNodeKey)
+ }
+ })
worker.on('exit', this.opts.exitHandler ?? EMPTY_FUNCTION)
worker.once('exit', () => {
this.removeWorkerNode(worker)
})
- this.pushWorkerNode(worker)
+ const workerNodeKey = this.addWorkerNode(worker)
- this.afterWorkerSetup(worker)
+ this.afterWorkerNodeSetup(workerNodeKey)
- return worker
+ return workerNodeKey
}
/**
- * This function is the listener registered for each worker message.
+ * Creates a new, completely set up dynamic worker node.
*
- * @returns The listener function to execute when a message is received from a worker.
+ * @returns New, completely set up dynamic worker node key.
*/
- protected workerListener (): (message: MessageValue<Response>) => void {
- return message => {
- if (message.id != null) {
- // Task execution response received
- const promiseResponse = this.promiseResponseMap.get(message.id)
- if (promiseResponse != null) {
- if (message.error != null) {
- promiseResponse.reject(message.error)
- } else {
- promiseResponse.resolve(message.data as Response)
- }
- this.afterTaskExecutionHook(promiseResponse.worker, message)
- this.promiseResponseMap.delete(message.id)
- const workerNodeKey = this.getWorkerNodeKey(promiseResponse.worker)
- if (
- this.opts.enableTasksQueue === true &&
- this.tasksQueueSize(workerNodeKey) > 0
- ) {
- this.executeTask(
- workerNodeKey,
- this.dequeueTask(workerNodeKey) as Task<Data>
- )
- }
- }
+ protected createAndSetupDynamicWorkerNode (): number {
+ const workerNodeKey = this.createAndSetupWorkerNode()
+ this.registerWorkerMessageListener(workerNodeKey, message => {
+ this.checkMessageWorkerId(message)
+ const localWorkerNodeKey = this.getWorkerNodeKeyByWorkerId(
+ message.workerId
+ )
+ const workerUsage = this.workerNodes[localWorkerNodeKey].usage
+ // Kill message received from worker
+ if (
+ isKillBehavior(KillBehaviors.HARD, message.kill) ||
+ (isKillBehavior(KillBehaviors.SOFT, message.kill) &&
+ ((this.opts.enableTasksQueue === false &&
+ workerUsage.tasks.executing === 0) ||
+ (this.opts.enableTasksQueue === true &&
+ workerUsage.tasks.executing === 0 &&
+ this.tasksQueueSize(localWorkerNodeKey) === 0)))
+ ) {
+ // Flag the worker node as not ready immediately
+ this.flagWorkerNodeAsNotReady(localWorkerNodeKey)
+ this.destroyWorkerNode(localWorkerNodeKey).catch(error => {
+ this.emitter?.emit(PoolEvents.error, error)
+ })
}
+ })
+ const workerInfo = this.getWorkerInfo(workerNodeKey)
+ this.sendToWorker(workerNodeKey, {
+ checkActive: true
+ })
+ if (this.taskFunctions.size > 0) {
+ for (const [taskFunctionName, taskFunction] of this.taskFunctions) {
+ this.sendTaskFunctionOperationToWorker(workerNodeKey, {
+ taskFunctionOperation: 'add',
+ taskFunctionName,
+ taskFunction: taskFunction.toString()
+ }).catch(error => {
+ this.emitter?.emit(PoolEvents.error, error)
+ })
+ }
+ }
+ workerInfo.dynamic = true
+ if (
+ this.workerChoiceStrategyContext.getStrategyPolicy().dynamicWorkerReady ||
+ this.workerChoiceStrategyContext.getStrategyPolicy().dynamicWorkerUsage
+ ) {
+ workerInfo.ready = true
}
+ this.checkAndEmitDynamicWorkerCreationEvents()
+ return workerNodeKey
}
- private checkAndEmitEvents (): void {
- if (this.opts.enableEvents === true) {
- if (this.busy) {
- this.emitter?.emit(PoolEvents.busy)
+ /**
+ * Registers a listener callback on the worker given its worker node key.
+ *
+ * @param workerNodeKey - The worker node key.
+ * @param listener - The message listener callback.
+ */
+ protected abstract registerWorkerMessageListener<
+ Message extends Data | Response
+ >(
+ workerNodeKey: number,
+ listener: (message: MessageValue<Message>) => void
+ ): void
+
+ /**
+ * Registers once a listener callback on the worker given its worker node key.
+ *
+ * @param workerNodeKey - The worker node key.
+ * @param listener - The message listener callback.
+ */
+ protected abstract registerOnceWorkerMessageListener<
+ Message extends Data | Response
+ >(
+ workerNodeKey: number,
+ listener: (message: MessageValue<Message>) => void
+ ): void
+
+ /**
+ * Deregisters a listener callback on the worker given its worker node key.
+ *
+ * @param workerNodeKey - The worker node key.
+ * @param listener - The message listener callback.
+ */
+ protected abstract deregisterWorkerMessageListener<
+ Message extends Data | Response
+ >(
+ workerNodeKey: number,
+ listener: (message: MessageValue<Message>) => void
+ ): void
+
+ /**
+ * Method hooked up after a worker node has been newly created.
+ * Can be overridden.
+ *
+ * @param workerNodeKey - The newly created worker node key.
+ */
+ protected afterWorkerNodeSetup (workerNodeKey: number): void {
+ // Listen to worker messages.
+ this.registerWorkerMessageListener(
+ workerNodeKey,
+ this.workerMessageListener.bind(this)
+ )
+ // Send the startup message to worker.
+ this.sendStartupMessageToWorker(workerNodeKey)
+ // Send the statistics message to worker.
+ this.sendStatisticsMessageToWorker(workerNodeKey)
+ if (this.opts.enableTasksQueue === true) {
+ if (this.opts.tasksQueueOptions?.taskStealing === true) {
+ this.workerNodes[workerNodeKey].addEventListener(
+ 'emptyqueue',
+ this.handleEmptyQueueEvent as EventListener
+ )
}
- if (this.type === PoolType.DYNAMIC && this.full) {
- this.emitter?.emit(PoolEvents.full)
+ if (this.opts.tasksQueueOptions?.tasksStealingOnBackPressure === true) {
+ this.workerNodes[workerNodeKey].addEventListener(
+ 'backpressure',
+ this.handleBackPressureEvent as EventListener
+ )
}
}
}
/**
- * Sets the given worker node its tasks usage in the pool.
+ * Sends the startup message to worker given its worker node key.
*
- * @param workerNode - The worker node.
- * @param tasksUsage - The worker node tasks usage.
+ * @param workerNodeKey - The worker node key.
*/
- private setWorkerNodeTasksUsage (
- workerNode: WorkerNode<Worker, Data>,
- tasksUsage: TasksUsage
+ protected abstract sendStartupMessageToWorker (workerNodeKey: number): void
+
+ /**
+ * Sends the statistics message to worker given its worker node key.
+ *
+ * @param workerNodeKey - The worker node key.
+ */
+ private sendStatisticsMessageToWorker (workerNodeKey: number): void {
+ this.sendToWorker(workerNodeKey, {
+ statistics: {
+ runTime:
+ this.workerChoiceStrategyContext.getTaskStatisticsRequirements()
+ .runTime.aggregate,
+ elu: this.workerChoiceStrategyContext.getTaskStatisticsRequirements()
+ .elu.aggregate
+ }
+ })
+ }
+
+ private redistributeQueuedTasks (workerNodeKey: number): void {
+ while (this.tasksQueueSize(workerNodeKey) > 0) {
+ const destinationWorkerNodeKey = this.workerNodes.reduce(
+ (minWorkerNodeKey, workerNode, workerNodeKey, workerNodes) => {
+ return workerNode.info.ready &&
+ workerNode.usage.tasks.queued <
+ workerNodes[minWorkerNodeKey].usage.tasks.queued
+ ? workerNodeKey
+ : minWorkerNodeKey
+ },
+ 0
+ )
+ const task = this.dequeueTask(workerNodeKey) as Task<Data>
+ if (this.shallExecuteTask(destinationWorkerNodeKey)) {
+ this.executeTask(destinationWorkerNodeKey, task)
+ } else {
+ this.enqueueTask(destinationWorkerNodeKey, task)
+ }
+ }
+ }
+
+ private updateTaskStolenStatisticsWorkerUsage (
+ workerNodeKey: number,
+ taskName: string
): void {
- workerNode.tasksUsage = tasksUsage
+ const workerNode = this.workerNodes[workerNodeKey]
+ if (workerNode?.usage != null) {
+ ++workerNode.usage.tasks.stolen
+ }
+ if (
+ this.shallUpdateTaskFunctionWorkerUsage(workerNodeKey) &&
+ workerNode.getTaskFunctionWorkerUsage(taskName) != null
+ ) {
+ const taskFunctionWorkerUsage = workerNode.getTaskFunctionWorkerUsage(
+ taskName
+ ) as WorkerUsage
+ ++taskFunctionWorkerUsage.tasks.stolen
+ }
+ }
+
+ private readonly handleEmptyQueueEvent = (
+ event: CustomEvent<WorkerNodeEventDetail>
+ ): void => {
+ const destinationWorkerNodeKey = this.getWorkerNodeKeyByWorkerId(
+ event.detail.workerId
+ )
+ const workerNodes = this.workerNodes
+ .slice()
+ .sort(
+ (workerNodeA, workerNodeB) =>
+ workerNodeB.usage.tasks.queued - workerNodeA.usage.tasks.queued
+ )
+ const sourceWorkerNode = workerNodes.find(
+ workerNode =>
+ workerNode.info.ready &&
+ workerNode.info.id !== event.detail.workerId &&
+ workerNode.usage.tasks.queued > 0
+ )
+ if (sourceWorkerNode != null) {
+ const task = sourceWorkerNode.popTask() as Task<Data>
+ if (this.shallExecuteTask(destinationWorkerNodeKey)) {
+ this.executeTask(destinationWorkerNodeKey, task)
+ } else {
+ this.enqueueTask(destinationWorkerNodeKey, task)
+ }
+ this.updateTaskStolenStatisticsWorkerUsage(
+ destinationWorkerNodeKey,
+ task.name as string
+ )
+ }
+ }
+
+ private readonly handleBackPressureEvent = (
+ event: CustomEvent<WorkerNodeEventDetail>
+ ): void => {
+ const sizeOffset = 1
+ if ((this.opts.tasksQueueOptions?.size as number) <= sizeOffset) {
+ return
+ }
+ const sourceWorkerNode =
+ this.workerNodes[this.getWorkerNodeKeyByWorkerId(event.detail.workerId)]
+ const workerNodes = this.workerNodes
+ .slice()
+ .sort(
+ (workerNodeA, workerNodeB) =>
+ workerNodeA.usage.tasks.queued - workerNodeB.usage.tasks.queued
+ )
+ for (const [workerNodeKey, workerNode] of workerNodes.entries()) {
+ if (
+ sourceWorkerNode.usage.tasks.queued > 0 &&
+ workerNode.info.ready &&
+ workerNode.info.id !== event.detail.workerId &&
+ workerNode.usage.tasks.queued <
+ (this.opts.tasksQueueOptions?.size as number) - sizeOffset
+ ) {
+ const task = sourceWorkerNode.popTask() as Task<Data>
+ if (this.shallExecuteTask(workerNodeKey)) {
+ this.executeTask(workerNodeKey, task)
+ } else {
+ this.enqueueTask(workerNodeKey, task)
+ }
+ this.updateTaskStolenStatisticsWorkerUsage(
+ workerNodeKey,
+ task.name as string
+ )
+ }
+ }
}
/**
- * Gets the given worker its tasks usage in the pool.
- *
- * @param worker - The worker.
- * @returns The worker tasks usage.
+ * This method is the message listener registered on each worker.
*/
- private getWorkerTasksUsage (worker: Worker): TasksUsage | undefined {
- const workerNodeKey = this.getWorkerNodeKey(worker)
- if (workerNodeKey !== -1) {
- return this.workerNodes[workerNodeKey].tasksUsage
+ protected workerMessageListener (message: MessageValue<Response>): void {
+ this.checkMessageWorkerId(message)
+ if (message.ready != null && message.taskFunctionNames != null) {
+ // Worker ready response received from worker
+ this.handleWorkerReadyResponse(message)
+ } else if (message.taskId != null) {
+ // Task execution response received from worker
+ this.handleTaskExecutionResponse(message)
+ } else if (message.taskFunctionNames != null) {
+ // Task function names message received from worker
+ this.getWorkerInfo(
+ this.getWorkerNodeKeyByWorkerId(message.workerId)
+ ).taskFunctionNames = message.taskFunctionNames
+ }
+ }
+
+ private handleWorkerReadyResponse (message: MessageValue<Response>): void {
+ if (message.ready === false) {
+ throw new Error(
+ `Worker ${message.workerId as number} failed to initialize`
+ )
+ }
+ const workerInfo = this.getWorkerInfo(
+ this.getWorkerNodeKeyByWorkerId(message.workerId)
+ )
+ workerInfo.ready = message.ready as boolean
+ workerInfo.taskFunctionNames = message.taskFunctionNames
+ if (this.ready) {
+ this.emitter?.emit(PoolEvents.ready, this.info)
+ }
+ }
+
+ private handleTaskExecutionResponse (message: MessageValue<Response>): void {
+ const { taskId, workerError, data } = message
+ const promiseResponse = this.promiseResponseMap.get(taskId as string)
+ if (promiseResponse != null) {
+ if (workerError != null) {
+ this.emitter?.emit(PoolEvents.taskError, workerError)
+ promiseResponse.reject(workerError.message)
+ } else {
+ promiseResponse.resolve(data as Response)
+ }
+ const workerNodeKey = promiseResponse.workerNodeKey
+ this.afterTaskExecutionHook(workerNodeKey, message)
+ this.workerChoiceStrategyContext.update(workerNodeKey)
+ this.promiseResponseMap.delete(taskId as string)
+ if (
+ this.opts.enableTasksQueue === true &&
+ this.tasksQueueSize(workerNodeKey) > 0 &&
+ this.workerNodes[workerNodeKey].usage.tasks.executing <
+ (this.opts.tasksQueueOptions?.concurrency as number)
+ ) {
+ this.executeTask(
+ workerNodeKey,
+ this.dequeueTask(workerNodeKey) as Task<Data>
+ )
+ }
+ }
+ }
+
+ private checkAndEmitTaskExecutionEvents (): void {
+ if (this.busy) {
+ this.emitter?.emit(PoolEvents.busy, this.info)
+ }
+ }
+
+ private checkAndEmitTaskQueuingEvents (): void {
+ if (this.hasBackPressure()) {
+ this.emitter?.emit(PoolEvents.backPressure, this.info)
+ }
+ }
+
+ private checkAndEmitDynamicWorkerCreationEvents (): void {
+ if (this.type === PoolTypes.dynamic) {
+ if (this.full) {
+ this.emitter?.emit(PoolEvents.full, this.info)
+ }
}
- throw new Error('Worker could not be found in the pool worker nodes')
}
/**
- * Pushes the given worker in the pool worker nodes.
+ * Gets the worker information given its worker node key.
*
- * @param worker - The worker.
- * @returns The worker nodes length.
+ * @param workerNodeKey - The worker node key.
+ * @returns The worker information.
*/
- private pushWorkerNode (worker: Worker): number {
- return this.workerNodes.push({
- worker,
- tasksUsage: {
- run: 0,
- running: 0,
- runTime: 0,
- runTimeHistory: new CircularArray(),
- avgRunTime: 0,
- medRunTime: 0,
- error: 0
- },
- tasksQueue: []
- })
+ protected getWorkerInfo (workerNodeKey: number): WorkerInfo {
+ return this.workerNodes[workerNodeKey]?.info
}
/**
- * Sets the given worker in the pool worker nodes.
+ * Adds the given worker in the pool worker nodes.
*
- * @param workerNodeKey - The worker node key.
* @param worker - The worker.
- * @param tasksUsage - The worker tasks usage.
- * @param tasksQueue - The worker task queue.
+ * @returns The added worker node key.
+ * @throws {@link https://nodejs.org/api/errors.html#class-error} If the added worker node is not found.
*/
- private setWorkerNode (
- workerNodeKey: number,
- worker: Worker,
- tasksUsage: TasksUsage,
- tasksQueue: Array<Task<Data>>
- ): void {
- this.workerNodes[workerNodeKey] = {
+ private addWorkerNode (worker: Worker): number {
+ const workerNode = new WorkerNode<Worker, Data>(
worker,
- tasksUsage,
- tasksQueue
+ this.opts.tasksQueueOptions?.size ?? Math.pow(this.maxSize, 2)
+ )
+ // Flag the worker node as ready at pool startup.
+ if (this.starting) {
+ workerNode.info.ready = true
}
+ this.workerNodes.push(workerNode)
+ const workerNodeKey = this.getWorkerNodeKeyByWorker(worker)
+ if (workerNodeKey === -1) {
+ throw new Error('Worker added not found in worker nodes')
+ }
+ return workerNodeKey
}
/**
* @param worker - The worker.
*/
private removeWorkerNode (worker: Worker): void {
- const workerNodeKey = this.getWorkerNodeKey(worker)
- this.workerNodes.splice(workerNodeKey, 1)
- this.workerChoiceStrategyContext.remove(workerNodeKey)
+ const workerNodeKey = this.getWorkerNodeKeyByWorker(worker)
+ if (workerNodeKey !== -1) {
+ this.workerNodes.splice(workerNodeKey, 1)
+ this.workerChoiceStrategyContext.remove(workerNodeKey)
+ }
+ }
+
+ protected flagWorkerNodeAsNotReady (workerNodeKey: number): void {
+ this.getWorkerInfo(workerNodeKey).ready = false
+ }
+
+ /** @inheritDoc */
+ public hasWorkerNodeBackPressure (workerNodeKey: number): boolean {
+ return (
+ this.opts.enableTasksQueue === true &&
+ this.workerNodes[workerNodeKey].hasBackPressure()
+ )
+ }
+
+ private hasBackPressure (): boolean {
+ return (
+ this.opts.enableTasksQueue === true &&
+ this.workerNodes.findIndex(
+ workerNode => !workerNode.hasBackPressure()
+ ) === -1
+ )
}
+ /**
+ * Executes the given task on the worker given its worker node key.
+ *
+ * @param workerNodeKey - The worker node key.
+ * @param task - The task to execute.
+ */
private executeTask (workerNodeKey: number, task: Task<Data>): void {
- this.beforeTaskExecutionHook(workerNodeKey)
- this.sendToWorker(this.workerNodes[workerNodeKey].worker, task)
+ this.beforeTaskExecutionHook(workerNodeKey, task)
+ this.sendToWorker(workerNodeKey, task, task.transferList)
+ this.checkAndEmitTaskExecutionEvents()
}
private enqueueTask (workerNodeKey: number, task: Task<Data>): number {
- return this.workerNodes[workerNodeKey].tasksQueue.push(task)
+ const tasksQueueSize = this.workerNodes[workerNodeKey].enqueueTask(task)
+ this.checkAndEmitTaskQueuingEvents()
+ return tasksQueueSize
}
private dequeueTask (workerNodeKey: number): Task<Data> | undefined {
- return this.workerNodes[workerNodeKey].tasksQueue.shift()
+ return this.workerNodes[workerNodeKey].dequeueTask()
}
private tasksQueueSize (workerNodeKey: number): number {
- return this.workerNodes[workerNodeKey].tasksQueue.length
+ return this.workerNodes[workerNodeKey].tasksQueueSize()
}
- private flushTasksQueue (workerNodeKey: number): void {
- if (this.tasksQueueSize(workerNodeKey) > 0) {
- for (const task of this.workerNodes[workerNodeKey].tasksQueue) {
- this.executeTask(workerNodeKey, task)
- }
+ protected flushTasksQueue (workerNodeKey: number): void {
+ while (this.tasksQueueSize(workerNodeKey) > 0) {
+ this.executeTask(
+ workerNodeKey,
+ this.dequeueTask(workerNodeKey) as Task<Data>
+ )
}
+ this.workerNodes[workerNodeKey].clearTasksQueue()
}
- private flushTasksQueueByWorker (worker: Worker): void {
- const workerNodeKey = this.getWorkerNodeKey(worker)
- this.flushTasksQueue(workerNodeKey)
+ private flushTasksQueues (): void {
+ for (const [workerNodeKey] of this.workerNodes.entries()) {
+ this.flushTasksQueue(workerNodeKey)
+ }
}
}