X-Git-Url: https://git.piment-noir.org/?a=blobdiff_plain;f=src%2Fpools%2Fabstract-pool.ts;h=fd8628100fe560b11c1b48765c0102d9bdb806e5;hb=301b5d97a2c9bcd278819b4f81c42c949da66d63;hp=2ffd292afab9a0b540826820935b4a0febd34057;hpb=b8818d59f9e410ce2e3b0103b8372b3fa1badf8f;p=poolifier.git diff --git a/src/pools/abstract-pool.ts b/src/pools/abstract-pool.ts index 2ffd292a..fd862810 100644 --- a/src/pools/abstract-pool.ts +++ b/src/pools/abstract-pool.ts @@ -1,125 +1,85 @@ -import EventEmitter from 'events' -import type { MessageValue } from '../utility-types' -import type { IPool } from './pool' +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' /** - * Callback invoked if the worker raised an error. - */ -export type ErrorHandler = (this: Worker, e: Error) => void - -/** - * Callback invoked when the worker has started successfully. - */ -export type OnlineHandler = (this: Worker) => void - -/** - * Callback invoked when the worker exits successfully. - */ -export type ExitHandler = (this: Worker, code: number) => void - -/** - * Basic interface that describes the minimum required implementation of listener events for a pool-worker. - */ -export interface IWorker { - on(event: 'error', handler: ErrorHandler): void - on(event: 'online', handler: OnlineHandler): void - on(event: 'exit', handler: ExitHandler): void - once(event: 'exit', handler: ExitHandler): void -} - -/** - * Options for a poolifier pool. - */ -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 non-useful warning messages. - * - * Will be used to set `maxListeners` on event emitters (workers are event emitters). - * - * @default 1000 - * @see [Node events emitter.setMaxListeners(n)](https://nodejs.org/api/events.html#events_emitter_setmaxlisteners_n) - */ - maxTasks?: number -} - -/** - * Internal poolifier pool emitter. - */ -class PoolEmitter extends EventEmitter {} - -/** - * Base class containing some shared logic for all poolifier pools. + * Base class that implements 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. - * @template Response Type of response of execution. + * @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 { - /** - * List of currently available workers. - */ - public readonly workers: Worker[] = [] +> implements IPoolInternal { + /** @inheritDoc */ + public readonly workerNodes: Array> = [] - /** - * Index for the next worker. - */ - public nextWorkerIndex: number = 0 - - /** - * - `key`: The `Worker` - * - `value`: Number of tasks that has been assigned to that worker since it started - */ - public readonly tasks: Map = new Map() + /** @inheritDoc */ + public readonly emitter?: PoolEmitter /** - * Emitter on which events can be listened to. + * The promise response map. * - * Events that can currently be listened to: + * - `key`: The message id of each submitted task. + * - `value`: An object that contains the worker, the promise resolve and reject callbacks. * - * - `'FullPool'` + * When we receive a message from the worker we get a map entry with the promise resolve/reject bound to the message. */ - public readonly emitter: PoolEmitter + protected promiseResponseMap: Map< + string, + PromiseResponseWrapper + > = new Map>() /** - * ID of the next message. + * Worker choice strategy context referencing a worker choice algorithm implementation. + * + * Default to a round robin algorithm. */ - protected nextMessageId: number = 0 + 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. Default: `{ maxTasks: 1000 }` + * @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 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) { - throw new Error('Please specify a file with a worker implementation') - } + 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() @@ -127,57 +87,177 @@ export abstract class AbstractPool< this.createAndSetupWorker() } - this.emitter = new PoolEmitter() + 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') + } + } + + 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') + } + } + + 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}'` + ) + } } + /** @inheritDoc */ + public abstract get type (): PoolType + /** - * Number of workers that this pool should manage. - * - * @returns Number of workers that this pool manages. - * @deprecated Only here for backward compatibility. + * Number of tasks concurrently running in the pool. */ - // eslint-disable-next-line spellcheck/spell-checker - public get numWorkers (): number { - return this.numberOfWorkers + private get numberOfRunningTasks (): number { + return this.promiseResponseMap.size } /** - * Index for the next worker. + * Gets the given worker its worker node key. * - * @returns Index for the next worker. - * @deprecated Only here for backward compatibility. + * @param worker - The worker. + * @returns The worker node key if the worker is found in the pool worker nodes, `-1` otherwise. */ - public get nextWorker (): number { - return this.nextWorkerIndex + 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 + ) } - public execute (data: Data): Promise { - // 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 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.workers.map(worker => this.destroyWorker(worker))) + await Promise.all( + this.workerNodes.map(async workerNode => { + await this.destroyWorker(workerNode.worker) + }) + ) } /** - * Shut down given worker. + * Shutdowns the given worker. * - * @param worker A worker within `workers`. + * @param worker - A worker within `workerNodes`. */ protected abstract destroyWorker (worker: Worker): void | Promise /** - * 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 run code before worker node are created in the abstract constructor. + * Can be overridden + * + * @virtual */ protected setupHook (): void { - // Can be overridden + // Intentionally empty } /** @@ -186,82 +266,100 @@ export abstract class AbstractPool< protected abstract isMain (): boolean /** - * Increase the number of tasks that the given workers has done. + * Hook executed before the worker task promise resolution. + * Can be overridden. * - * @param worker Workers whose tasks are increased. + * @param workerNodeKey - The worker node key. */ - protected increaseWorkersTask (worker: Worker): void { - const numberOfTasksTheWorkerHas = this.tasks.get(worker) - if (numberOfTasksTheWorkerHas !== undefined) { - this.tasks.set(worker, numberOfTasksTheWorkerHas + 1) - } else { - throw Error('Worker could not be found in tasks map') - } + protected beforePromiseResponseHook (workerNodeKey: number): void { + ++this.workerNodes[workerNodeKey].tasksUsage.running } /** - * Removes the given worker from the pool. + * Hook executed after the worker task promise resolution. + * Can be overridden. * - * @param worker Worker that will be removed. + * @param worker - The worker. + * @param message - The received message. */ - 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) + 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) + } + } } /** - * Choose a worker for the next task. + * Chooses a worker node for the next task. * - * The default implementation uses a round robin algorithm to distribute the load. + * The default uses a round robin algorithm to distribute the load. * - * @returns Worker. + * @returns [worker node key, worker node]. */ - protected chooseWorker (): Worker { - const chosenWorker = this.workers[this.nextWorkerIndex] - this.nextWorkerIndex = - this.workers.length - 1 === this.nextWorkerIndex - ? 0 - : this.nextWorkerIndex + 1 - return chosenWorker + 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]] } /** - * 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 ): void + /** + * 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 abstract unregisterWorkerMessageListener< - Message extends Data | Response - > (worker: Worker, listener: (message: MessageValue) => void): void - - protected internalExecute ( - worker: Worker, - messageId: number - ): Promise { - return new Promise((resolve, reject) => { - const listener: (message: MessageValue) => void = message => { - if (message.id === messageId) { - this.unregisterWorkerMessageListener(worker, listener) - this.increaseWorkersTask(worker) - if (message.error) reject(message.error) - else resolve(message.data as Response) - } - } - this.registerWorkerMessageListener(worker, listener) - }) - } + >(worker: Worker, listener: (message: MessageValue) => void): void /** * Returns a newly created worker. @@ -269,34 +367,168 @@ export abstract class AbstractPool< protected abstract createWorker (): Worker /** - * Function that can be hooked up when a worker has been newly created and moved to the workers registry. + * 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. + * 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. + * @param worker - The newly created worker. */ protected abstract afterWorkerSetup (worker: Worker): void /** - * Creates a new worker for this pool and sets it up completely. + * 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: Worker = this.createWorker() - - worker.on('error', this.opts.errorHandler ?? (() => {})) - worker.on('online', this.opts.onlineHandler ?? (() => {})) - worker.on('exit', this.opts.exitHandler ?? (() => {})) - worker.once('exit', () => this.removeWorker(worker)) - - this.workers.push(worker) + const worker = this.createWorker() + + 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) + }) - // Init tasks map - this.tasks.set(worker, 0) + this.pushWorkerNode(worker) this.afterWorkerSetup(worker) 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) + } + } + } + } + + 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 + }) + }) + } + + private checkAndEmitBusy (): void { + if (this.opts.enableEvents === true && this.busy) { + this.emitter?.emit(PoolEvents.busy) + } + } + + private checkAndEmitFull (): void { + if ( + this.type === PoolType.DYNAMIC && + this.opts.enableEvents === true && + this.full + ) { + this.emitter?.emit(PoolEvents.full) + } + } + + /** + * 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') + } + + /** + * 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 + } }