X-Git-Url: https://git.piment-noir.org/?a=blobdiff_plain;f=src%2Fpools%2Fabstract-pool.ts;h=fd8628100fe560b11c1b48765c0102d9bdb806e5;hb=301b5d97a2c9bcd278819b4f81c42c949da66d63;hp=1ccaca8b207c613359265eb757d74dffc8c47176;hpb=afbc1e280c219008e0afeddc6bf4ae2d00a85b2e;p=poolifier.git diff --git a/src/pools/abstract-pool.ts b/src/pools/abstract-pool.ts index 1ccaca8b..fd862810 100644 --- a/src/pools/abstract-pool.ts +++ b/src/pools/abstract-pool.ts @@ -1,174 +1,534 @@ -import EventEmitter from 'events' -import type { MessageValue } from '../utility-types' -import type { IPool } from './pool' - -export type ErrorHandler = (this: Worker, e: Error) => void -export type OnlineHandler = (this: Worker) => void -export type ExitHandler = (this: Worker, code: number) => void - -export interface IWorker { - on(event: 'error', handler: ErrorHandler): void - on(event: 'online', handler: OnlineHandler): void - on(event: 'exit', handler: ExitHandler): void -} - -export interface PoolOptions { - /** - * A function that will listen for error event on each worker. - */ - errorHandler?: ErrorHandler - /** - * A function that will listen for online event on each worker. - */ - onlineHandler?: OnlineHandler - /** - * A function that will listen for exit event on each worker. - */ - exitHandler?: ExitHandler - /** - * This is just to avoid not useful warnings message, is used to set `maxListeners` on event emitters (workers are event emitters). - * - * @default 1000 - */ - maxTasks?: number -} - -class PoolEmitter extends EventEmitter {} +import crypto from 'node:crypto' +import type { MessageValue, PromiseResponseWrapper } from '../utility-types' +import { EMPTY_FUNCTION, median } from '../utils' +import { KillBehaviors, isKillBehavior } from '../worker/worker-options' +import { PoolEvents, type PoolOptions } 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 { + WorkerChoiceStrategies, + type WorkerChoiceStrategy +} from './selection-strategies/selection-strategies-types' +import { WorkerChoiceStrategyContext } from './selection-strategies/worker-choice-strategy-context' +import { CircularArray } from '../circular-array' +/** + * 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. + */ export abstract class AbstractPool< Worker extends IWorker, Data = unknown, Response = unknown -> implements IPool { - public readonly workers: Worker[] = [] - public nextWorker: number = 0 +> implements IPoolInternal { + /** @inheritDoc */ + public readonly workerNodes: Array> = [] + + /** @inheritDoc */ + public readonly emitter?: PoolEmitter /** - * `workerId` as key and an integer value + * The promise response map. + * + * - `key`: The message id of each submitted task. + * - `value`: An object that contains the worker, the 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. */ - public readonly tasks: Map = new Map() + protected promiseResponseMap: Map< + string, + PromiseResponseWrapper + > = new Map>() - public readonly emitter: PoolEmitter - - protected id: number = 0 + /** + * Worker choice strategy context referencing a worker choice algorithm implementation. + * + * Default to a round robin algorithm. + */ + protected workerChoiceStrategyContext: WorkerChoiceStrategyContext< + Worker, + Data, + Response + > + /** + * 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. + */ public constructor ( - public readonly numWorkers: number, + public readonly numberOfWorkers: number, public readonly filePath: string, - public readonly opts: PoolOptions = { maxTasks: 1000 } + public readonly opts: PoolOptions ) { if (!this.isMain()) { throw new Error('Cannot start a pool from a worker!') } - // TODO christopher 2021-02-07: Improve this check e.g. with a pattern or blank check - if (!this.filePath) { + this.checkNumberOfWorkers(this.numberOfWorkers) + this.checkFilePath(this.filePath) + this.checkPoolOptions(this.opts) + + this.chooseWorkerNode.bind(this) + this.internalExecute.bind(this) + this.checkAndEmitFull.bind(this) + this.checkAndEmitBusy.bind(this) + this.sendToWorker.bind(this) + + this.setupHook() + + for (let i = 1; i <= this.numberOfWorkers; i++) { + this.createAndSetupWorker() + } + + if (this.opts.enableEvents === true) { + this.emitter = new PoolEmitter() + } + this.workerChoiceStrategyContext = new WorkerChoiceStrategyContext< + Worker, + Data, + Response + >(this, this.opts.workerChoiceStrategy) + } + + 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() + 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 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') + } + } - for (let i = 1; i <= this.numWorkers; i++) { - this.internalNewWorker() + private checkPoolOptions (opts: PoolOptions): void { + this.opts.workerChoiceStrategy = + opts.workerChoiceStrategy ?? WorkerChoiceStrategies.ROUND_ROBIN + this.checkValidWorkerChoiceStrategy(this.opts.workerChoiceStrategy) + this.opts.enableEvents = opts.enableEvents ?? true + } + + private checkValidWorkerChoiceStrategy ( + workerChoiceStrategy: WorkerChoiceStrategy + ): void { + if (!Object.values(WorkerChoiceStrategies).includes(workerChoiceStrategy)) { + throw new Error( + `Invalid worker choice strategy '${workerChoiceStrategy}'` + ) } + } - this.emitter = new PoolEmitter() + /** @inheritDoc */ + public abstract get type (): PoolType + + /** + * Number of tasks concurrently running in the pool. + */ + private get numberOfRunningTasks (): number { + return this.promiseResponseMap.size + } + + /** + * 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. + */ + private getWorkerNodeKey (worker: Worker): number { + return this.workerNodes.findIndex( + workerNode => workerNode.worker === worker + ) + } + + /** @inheritDoc */ + public setWorkerChoiceStrategy ( + workerChoiceStrategy: WorkerChoiceStrategy + ): void { + this.checkValidWorkerChoiceStrategy(workerChoiceStrategy) + this.opts.workerChoiceStrategy = workerChoiceStrategy + for (const [index, workerNode] of this.workerNodes.entries()) { + this.setWorkerNode( + index, + workerNode.worker, + { + run: 0, + running: 0, + runTime: 0, + runTimeHistory: new CircularArray(), + avgRunTime: 0, + medRunTime: 0, + error: 0 + }, + workerNode.tasksQueue + ) + } + this.workerChoiceStrategyContext.setWorkerChoiceStrategy( + workerChoiceStrategy + ) + } + + /** @inheritDoc */ + public abstract get full (): boolean + + /** @inheritDoc */ + public abstract get busy (): boolean + + protected internalBusy (): boolean { + return ( + this.numberOfRunningTasks >= this.numberOfWorkers && + this.findFreeWorkerNodeKey() === -1 + ) + } + + /** @inheritDoc */ + public findFreeWorkerNodeKey (): number { + return this.workerNodes.findIndex(workerNode => { + return workerNode.tasksUsage?.running === 0 + }) + } + + /** @inheritDoc */ + public async execute (data: Data): Promise { + const [workerNodeKey, workerNode] = this.chooseWorkerNode() + const submittedTask: Task = { + // eslint-disable-next-line @typescript-eslint/consistent-type-assertions + data: data ?? ({} as Data), + id: crypto.randomUUID() + } + const res = this.internalExecute(workerNodeKey, workerNode, submittedTask) + let currentTask: Task + // FIXME: Add sensible conditions to start tasks queuing on the worker node + if (this.tasksQueueLength(workerNodeKey) > 0) { + currentTask = this.dequeueTask(workerNodeKey) as Task + this.enqueueTask(workerNodeKey, submittedTask) + } else { + currentTask = submittedTask + } + this.sendToWorker(workerNode.worker, currentTask) + this.checkAndEmitFull() + this.checkAndEmitBusy() + // eslint-disable-next-line @typescript-eslint/return-await + return res + } + + /** @inheritDoc */ + public async destroy (): Promise { + await Promise.all( + this.workerNodes.map(async workerNode => { + await this.destroyWorker(workerNode.worker) + }) + ) } + /** + * Shutdowns the given worker. + * + * @param worker - A worker within `workerNodes`. + */ + protected abstract destroyWorker (worker: Worker): void | Promise + + /** + * Setup hook to run code before worker node are created in the abstract constructor. + * Can be overridden + * + * @virtual + */ protected setupHook (): void { - // Can be overridden + // Intentionally empty } + /** + * Should return whether the worker is the main worker or not. + */ protected abstract isMain (): boolean - public async destroy (): Promise { - for (const worker of this.workers) { - await this.destroyWorker(worker) + /** + * Hook executed before the worker task promise resolution. + * Can be overridden. + * + * @param workerNodeKey - The worker node key. + */ + protected beforePromiseResponseHook (workerNodeKey: number): void { + ++this.workerNodes[workerNodeKey].tasksUsage.running + } + + /** + * Hook executed after the worker task promise resolution. + * Can be overridden. + * + * @param worker - The worker. + * @param message - The received message. + */ + protected afterPromiseResponseHook ( + worker: Worker, + message: MessageValue + ): 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) + } } } - protected abstract destroyWorker (worker: Worker): void | Promise + /** + * Chooses a worker node for the next task. + * + * The default uses a round robin algorithm to distribute the load. + * + * @returns [worker node key, worker node]. + */ + protected chooseWorkerNode (): [number, WorkerNode] { + let workerNodeKey: number + if ( + this.type === PoolType.DYNAMIC && + !this.full && + this.findFreeWorkerNodeKey() === -1 + ) { + 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, means that no new tasks are submitted to that worker for a while ( > maxInactiveTime) + void this.destroyWorker(workerCreated) + } + }) + workerNodeKey = this.getWorkerNodeKey(workerCreated) + } else { + workerNodeKey = this.workerChoiceStrategyContext.execute() + } + return [workerNodeKey, this.workerNodes[workerNodeKey]] + } + /** + * Sends a message to the given worker. + * + * @param worker - The worker which should receive the message. + * @param message - The message. + */ protected abstract sendToWorker ( worker: Worker, message: MessageValue ): void - protected addWorker (worker: Worker): void { - const previousWorkerIndex = this.tasks.get(worker) - if (previousWorkerIndex !== undefined) { - this.tasks.set(worker, previousWorkerIndex + 1) - } else { - throw Error('Worker could not be found in tasks map') - } - } + /** + * Registers a listener callback on the given worker. + * + * @param worker - The worker which should register a listener. + * @param listener - The message listener callback. + */ + protected abstract registerWorkerMessageListener< + Message extends Data | Response + >(worker: Worker, listener: (message: MessageValue) => void): void - 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) - } + /** + * Returns a newly created worker. + */ + protected abstract createWorker (): Worker + + /** + * 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. + * + * @param worker - The newly created worker. + */ + protected abstract afterWorkerSetup (worker: Worker): void /** - * Execute the task specified into the constructor with the data parameter. + * Creates a new worker and sets it up completely in the pool worker nodes. * - * @param data The input for the task specified. - * @returns Promise that is resolved when the task is done. + * @returns New, completely set up worker. */ - public execute (data: Data): Promise { - // configure worker to handle message with the specified task - const worker = this.chooseWorker() - this.addWorker(worker) - const id = ++this.id - const res = this.internalExecute(worker, id) - this.sendToWorker(worker, { data: data || ({} as Data), id: id }) - return res - } + protected createAndSetupWorker (): Worker { + const worker = this.createWorker() - protected abstract registerWorkerMessageListener ( - port: Worker, - listener: (message: MessageValue) => void - ): void + 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('exit', this.opts.exitHandler ?? EMPTY_FUNCTION) + worker.once('exit', () => { + this.removeWorkerNode(worker) + }) - protected abstract unregisterWorkerMessageListener ( - port: Worker, - listener: (message: MessageValue) => void - ): void + this.pushWorkerNode(worker) + + this.afterWorkerSetup(worker) - protected internalExecute (worker: Worker, id: number): Promise { - return new Promise((resolve, reject) => { - const listener: (message: MessageValue) => void = message => { - if (message.id === id) { - this.unregisterWorkerMessageListener(worker, listener) - this.addWorker(worker) - if (message.error) reject(message.error) - else resolve(message.data as Response) + return worker + } + + /** + * This function is the listener registered for each worker. + * + * @returns The listener function to execute when a message is received from a worker. + */ + protected workerListener (): (message: MessageValue) => void { + return message => { + if (message.id != null) { + // Task 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.afterPromiseResponseHook(promiseResponse.worker, message) + this.promiseResponseMap.delete(message.id) } } - this.registerWorkerMessageListener(worker, listener) + } + } + + private async internalExecute ( + workerNodeKey: number, + workerNode: WorkerNode, + task: Task + ): Promise { + this.beforePromiseResponseHook(workerNodeKey) + return await new Promise((resolve, reject) => { + this.promiseResponseMap.set(task.id, { + resolve, + reject, + worker: workerNode.worker + }) }) } - protected chooseWorker (): Worker { - this.nextWorker = - this.nextWorker === this.workers.length - 1 ? 0 : this.nextWorker + 1 - return this.workers[this.nextWorker] + private checkAndEmitBusy (): void { + if (this.opts.enableEvents === true && this.busy) { + this.emitter?.emit(PoolEvents.busy) + } } - protected abstract newWorker (): Worker + private checkAndEmitFull (): void { + if ( + this.type === PoolType.DYNAMIC && + this.opts.enableEvents === true && + this.full + ) { + this.emitter?.emit(PoolEvents.full) + } + } - protected abstract afterNewWorkerPushed (worker: Worker): void + /** + * Gets the given worker its tasks usage in the pool. + * + * @param worker - The worker. + * @returns The worker tasks usage. + */ + private getWorkerTasksUsage (worker: Worker): TasksUsage | undefined { + const workerNodeKey = this.getWorkerNodeKey(worker) + if (workerNodeKey !== -1) { + return this.workerNodes[workerNodeKey].tasksUsage + } + throw new Error('Worker could not be found in the pool worker nodes') + } - protected internalNewWorker (): Worker { - const worker: Worker = this.newWorker() - worker.on('error', this.opts.errorHandler ?? (() => {})) - worker.on('online', this.opts.onlineHandler ?? (() => {})) - // TODO handle properly when a worker exit - worker.on('exit', this.opts.exitHandler ?? (() => {})) - this.workers.push(worker) - this.afterNewWorkerPushed(worker) - // init tasks map - this.tasks.set(worker, 0) - return worker + /** + * 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({ + worker, + tasksUsage: { + run: 0, + running: 0, + runTime: 0, + runTimeHistory: new CircularArray(), + avgRunTime: 0, + medRunTime: 0, + error: 0 + }, + tasksQueue: [] + }) + } + + /** + * Sets 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. + */ + private setWorkerNode ( + workerNodeKey: number, + worker: Worker, + tasksUsage: TasksUsage, + tasksQueue: Array> + ): void { + this.workerNodes[workerNodeKey] = { + worker, + tasksUsage, + tasksQueue + } + } + + /** + * Removes the given worker from the pool worker nodes. + * + * @param worker - The worker. + */ + protected removeWorkerNode (worker: Worker): void { + const workerNodeKey = this.getWorkerNodeKey(worker) + this.workerNodes.splice(workerNodeKey, 1) + this.workerChoiceStrategyContext.remove(workerNodeKey) + } + + protected enqueueTask (workerNodeKey: number, task: Task): void { + this.workerNodes[workerNodeKey].tasksQueue.push(task) + } + + protected dequeueTask (workerNodeKey: number): Task | undefined { + return this.workerNodes[workerNodeKey].tasksQueue.shift() + } + + protected tasksQueueLength (workerNodeKey: number): number { + return this.workerNodes[workerNodeKey].tasksQueue.length } }