X-Git-Url: https://git.piment-noir.org/?a=blobdiff_plain;f=src%2Fpools%2Fabstract-pool.ts;h=72e830745558831db7933dfcfd5b6c8a03b35d78;hb=473c717a499d52ce8a069c43ee168b70cb5701f1;hp=f6ed280cc3bbcf39b6a4aed1faa37603bf17786d;hpb=45dbbb14328a173cad05ddcf21b5acf7f6460bb8;p=poolifier.git diff --git a/src/pools/abstract-pool.ts b/src/pools/abstract-pool.ts index f6ed280c..72e83074 100644 --- a/src/pools/abstract-pool.ts +++ b/src/pools/abstract-pool.ts @@ -1,172 +1,227 @@ -import EventEmitter from 'events' -import type { MessageValue } from '../utility-types' -import type { IPool } from './pool' +import type { + MessageValue, + PromiseWorkerResponseWrapper +} from '../utility-types' +import { EMPTY_FUNCTION } from '../utils' +import { isKillBehavior, KillBehaviors } from '../worker/worker-options' +import type { PoolOptions } from './pool' +import { PoolEmitter } from './pool' +import type { IPoolInternal, TasksUsage } from './pool-internal' +import { PoolType } from './pool-internal' +import type { IPoolWorker } from './pool-worker' +import { + WorkerChoiceStrategies, + WorkerChoiceStrategy +} from './selection-strategies/selection-strategies-types' +import { WorkerChoiceStrategyContext } from './selection-strategies/worker-choice-strategy-context' /** - * 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. + * @template Data Type of data sent to the worker. This can only be serializable data. + * @template Response Type of response of execution. This can only be serializable data. */ export abstract class AbstractPool< - Worker extends IWorker, + Worker extends IPoolWorker, Data = unknown, Response = unknown -> implements IPool { - /** - * List of currently available workers. - */ +> implements IPoolInternal { + /** @inheritDoc */ public readonly workers: Worker[] = [] - /** - * Index for the next worker. - */ - public nextWorkerIndex: number = 0 + /** @inheritDoc */ + public readonly workersTasksUsage: Map = new Map< + Worker, + TasksUsage + >() - /** - * - `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 map. * - * Events that can currently be listened to: + * - `key`: This is the message Id of each submitted task. + * - `value`: An object that contains the worker, the resolve function and the reject function. * - * - `'FullPool'` + * When we receive a message from the worker we get a map entry and resolve/reject the promise based on the message. */ - public readonly emitter: PoolEmitter + protected promiseMap: Map< + number, + PromiseWorkerResponseWrapper + > = new Map>() /** - * ID of the next message. + * Id of the next message. */ protected nextMessageId: number = 0 + /** + * Worker choice strategy instance implementing the worker choice algorithm. + * + * Default to a strategy implementing 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. Default: `{ maxTasks: 1000 }` + * @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()) { + if (this.isMain() === false) { 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.setupHook() for (let i = 1; i <= this.numberOfWorkers; i++) { this.createAndSetupWorker() } - this.emitter = new PoolEmitter() + if (this.opts.enableEvents === true) { + this.emitter = new PoolEmitter() + } + this.workerChoiceStrategyContext = new WorkerChoiceStrategyContext( + this, + () => { + const workerCreated = this.createAndSetupWorker() + this.registerWorkerMessageListener(workerCreated, message => { + if ( + isKillBehavior(KillBehaviors.HARD, message.kill) || + this.getWorkerRunningTasks(workerCreated) === 0 + ) { + // Kill received from the worker, means that no new tasks are submitted to that worker for a while ( > maxInactiveTime) + this.destroyWorker(workerCreated) as void + } + }) + return workerCreated + }, + this.opts.workerChoiceStrategy + ) } - /** - * Number of workers that this pool should manage. - * - * @returns Number of workers that this pool manages. - * @deprecated Only here for backward compatibility. - */ - // eslint-disable-next-line spellcheck/spell-checker - public get numWorkers (): number { - return this.numberOfWorkers + private checkFilePath (filePath: string): void { + if (!filePath) { + throw new Error('Please specify a file with a worker implementation') + } } - /** - * Index for the next worker. - * - * @returns Index for the next worker. - * @deprecated Only here for backward compatibility. - */ - public get nextWorker (): number { - return this.nextWorkerIndex + 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) === false) { + 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.opts.enableEvents = opts.enableEvents ?? true + } + + /** @inheritDoc */ + public abstract get type (): PoolType + + /** @inheritDoc */ + public get numberOfRunningTasks (): number { + return this.promiseMap.size + } + + /** @inheritDoc */ + public getWorkerIndex (worker: Worker): number { + return this.workers.indexOf(worker) + } + + /** @inheritDoc */ + public getWorkerRunningTasks (worker: Worker): number | undefined { + return this.workersTasksUsage.get(worker)?.running + } + + /** @inheritDoc */ + public getWorkerAverageTasksRunTime (worker: Worker): number | undefined { + return this.workersTasksUsage.get(worker)?.avgRunTime + } + + /** @inheritDoc */ + public setWorkerChoiceStrategy ( + workerChoiceStrategy: WorkerChoiceStrategy + ): void { + this.opts.workerChoiceStrategy = workerChoiceStrategy + for (const worker of this.workers) { + this.resetWorkerTasksUsage(worker) + } + this.workerChoiceStrategyContext.setWorkerChoiceStrategy( + workerChoiceStrategy + ) } + /** @inheritDoc */ + public abstract get busy (): boolean + + protected internalGetBusyStatus (): boolean { + return ( + this.numberOfRunningTasks >= this.numberOfWorkers && + this.findFreeWorker() === false + ) + } + + /** @inheritDoc */ + public findFreeWorker (): Worker | false { + for (const worker of this.workers) { + if (this.getWorkerRunningTasks(worker) === 0) { + // A worker is free, return the matching worker + return worker + } + } + return false + } + + /** @inheritDoc */ 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 }) + const res = this.internalExecute(worker, this.nextMessageId) + this.checkAndEmitBusy() + this.sendToWorker(worker, { + data: data ?? ({} as Data), + id: this.nextMessageId + }) + ++this.nextMessageId return res } + /** @inheritDoc */ public async destroy (): Promise { await Promise.all(this.workers.map(worker => this.destroyWorker(worker))) } /** - * Shut down given worker. + * Shutdowns given worker. * * @param worker A worker within `workers`. */ @@ -186,47 +241,55 @@ 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 worker The worker. */ - 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 beforePromiseWorkerResponseHook (worker: Worker): void { + this.increaseWorkerRunningTasks(worker) + } + + /** + * Hook executed after the worker task promise resolution. + * Can be overridden. + * + * @param message The received message. + * @param promise The Promise response. + */ + protected afterPromiseWorkerResponseHook ( + message: MessageValue, + promise: PromiseWorkerResponseWrapper + ): void { + this.decreaseWorkerRunningTasks(promise.worker) + this.stepWorkerRunTasks(promise.worker, 1) + this.updateWorkerTasksRunTime(promise.worker, message.taskRunTime) } /** * Removes the given worker from the pool. * - * @param worker Worker that will be removed. + * @param worker The worker that will be removed. */ 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) + this.workers.splice(this.getWorkerIndex(worker), 1) + this.removeWorkerTasksUsage(worker) } /** - * Choose a worker for the next task. + * Chooses a worker for the next task. * * The default implementation uses a round robin algorithm to distribute the load. * * @returns Worker. */ protected chooseWorker (): Worker { - const chosenWorker = this.workers[this.nextWorkerIndex] - this.nextWorkerIndex++ - this.nextWorkerIndex %= this.workers.length - return chosenWorker + return this.workerChoiceStrategyContext.execute() } /** - * 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. @@ -236,30 +299,23 @@ export abstract class AbstractPool< message: MessageValue ): void - protected abstract registerWorkerMessageListener ( - port: Worker, - listener: (message: MessageValue) => void - ): void - - protected abstract unregisterWorkerMessageListener ( - port: Worker, - listener: (message: MessageValue) => void - ): void + /** + * Registers a listener callback on a 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 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) + this.beforePromiseWorkerResponseHook(worker) + return new Promise((resolve, reject) => { + this.promiseMap.set(messageId, { resolve, reject, worker }) }) } @@ -283,20 +339,166 @@ export abstract class AbstractPool< * @returns New, completely set up worker. */ protected createAndSetupWorker (): Worker { - const worker: Worker = this.createWorker() + const worker = this.createWorker() - worker.on('error', this.opts.errorHandler ?? (() => {})) - worker.on('online', this.opts.onlineHandler ?? (() => {})) - worker.on('exit', this.opts.exitHandler ?? (() => {})) + 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.removeWorker(worker)) this.workers.push(worker) - // Init tasks map - this.tasks.set(worker, 0) + // Init worker tasks usage map + this.initWorkerTasksUsage(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 !== undefined) { + const promise = this.promiseMap.get(message.id) + if (promise !== undefined) { + if (message.error) { + promise.reject(message.error) + } else { + promise.resolve(message.data as Response) + } + this.afterPromiseWorkerResponseHook(message, promise) + this.promiseMap.delete(message.id) + } + } + } + } + + private checkAndEmitBusy (): void { + if (this.opts.enableEvents === true && this.busy === true) { + this.emitter?.emit('busy') + } + } + + /** + * Increases the number of tasks that the given worker has applied. + * + * @param worker Worker which running tasks is increased. + */ + private increaseWorkerRunningTasks (worker: Worker): void { + this.stepWorkerRunningTasks(worker, 1) + } + + /** + * Decreases the number of tasks that the given worker has applied. + * + * @param worker Worker which running tasks is decreased. + */ + private decreaseWorkerRunningTasks (worker: Worker): void { + this.stepWorkerRunningTasks(worker, -1) + } + + /** + * Steps the number of tasks that the given worker has applied. + * + * @param worker Worker which running tasks are stepped. + * @param step Number of running tasks step. + */ + private stepWorkerRunningTasks (worker: Worker, step: number): void { + if (this.checkWorkerTasksUsage(worker) === true) { + const tasksUsage = this.workersTasksUsage.get(worker) as TasksUsage + tasksUsage.running = tasksUsage.running + step + this.workersTasksUsage.set(worker, tasksUsage) + } + } + + /** + * Steps the number of tasks that the given worker has run. + * + * @param worker Worker which has run tasks. + * @param step Number of run tasks step. + */ + private stepWorkerRunTasks (worker: Worker, step: number): void { + if (this.checkWorkerTasksUsage(worker) === true) { + const tasksUsage = this.workersTasksUsage.get(worker) as TasksUsage + tasksUsage.run = tasksUsage.run + step + this.workersTasksUsage.set(worker, tasksUsage) + } + } + + /** + * Updates tasks runtime for the given worker. + * + * @param worker Worker which run the task. + * @param taskRunTime Worker task runtime. + */ + private updateWorkerTasksRunTime ( + worker: Worker, + taskRunTime: number | undefined + ): void { + if ( + this.workerChoiceStrategyContext.getWorkerChoiceStrategy() + .requiredStatistics.runTime === true && + this.checkWorkerTasksUsage(worker) === true + ) { + const tasksUsage = this.workersTasksUsage.get(worker) as TasksUsage + tasksUsage.runTime += taskRunTime ?? 0 + if (tasksUsage.run !== 0) { + tasksUsage.avgRunTime = tasksUsage.runTime / tasksUsage.run + } + this.workersTasksUsage.set(worker, tasksUsage) + } + } + + /** + * Checks if the given worker is registered in the workers tasks usage map. + * + * @param worker Worker to check. + * @returns `true` if the worker is registered in the workers tasks usage map. `false` otherwise. + */ + private checkWorkerTasksUsage (worker: Worker): boolean { + const hasTasksUsage = this.workersTasksUsage.has(worker) + if (hasTasksUsage === false) { + throw new Error('Worker could not be found in workers tasks usage map') + } + return hasTasksUsage + } + + /** + * Initializes tasks usage statistics. + * + * @param worker The worker. + */ + private initWorkerTasksUsage (worker: Worker): void { + this.workersTasksUsage.set(worker, { + run: 0, + running: 0, + runTime: 0, + avgRunTime: 0 + }) + } + + /** + * Removes worker tasks usage statistics. + * + * @param worker The worker. + */ + private removeWorkerTasksUsage (worker: Worker): void { + this.workersTasksUsage.delete(worker) + } + + /** + * Resets worker tasks usage statistics. + * + * @param worker The worker. + */ + private resetWorkerTasksUsage (worker: Worker): void { + this.removeWorkerTasksUsage(worker) + this.initWorkerTasksUsage(worker) + } }