src/pools/worker-node.ts

   1 import { EventEmitter } from 'node:events'
   2 import { MessageChannel } from 'node:worker_threads'
   3
   4 import { CircularArray } from '../circular-array.js'
   5 import { Deque } from '../deque.js'
   6 import { PriorityQueue } from '../priority-queue.js'
   7 import type { Task } from '../utility-types.js'
   8 import { DEFAULT_TASK_NAME } from '../utils.js'
   9 import {
  10   checkWorkerNodeArguments,
  11   createWorker,
  12   getWorkerId,
  13   getWorkerType
  14 } from './utils.js'
  15 import {
  16   type EventHandler,
  17   type IWorker,
  18   type IWorkerNode,
  19   type StrategyData,
  20   type WorkerInfo,
  21   type WorkerNodeOptions,
  22   type WorkerType,
  23   WorkerTypes,
  24   type WorkerUsage
  25 } from './worker.js'
  26
  27 /**
  28  * Worker node.
  29  *
  30  * @typeParam Worker - Type of worker.
  31  * @typeParam Data - Type of data sent to the worker. This can only be structured-cloneable data.
  32  */
  33 export class WorkerNode<Worker extends IWorker, Data = unknown>
  34   extends EventEmitter
  35   implements IWorkerNode<Worker, Data> {
  36   /** @inheritdoc */
  37   public readonly worker: Worker
  38   /** @inheritdoc */
  39   public readonly info: WorkerInfo
  40   /** @inheritdoc */
  41   public usage: WorkerUsage
  42   /** @inheritdoc */
  43   public strategyData?: StrategyData
  44   /** @inheritdoc */
  45   public messageChannel?: MessageChannel
  46   /** @inheritdoc */
  47   public tasksQueueBackPressureSize: number
  48   private readonly tasksQueue: Deque<Task<Data>>
  49   private readonly tasksQueue2 = new PriorityQueue<Task<Data>>()
  50   private onBackPressureStarted: boolean
  51   private readonly taskFunctionsUsage: Map<string, WorkerUsage>
  52
  53   /**
  54    * Constructs a new worker node.
  55    *
  56    * @param type - The worker type.
  57    * @param filePath - Path to the worker file.
  58    * @param opts - The worker node options.
  59    */
  60   constructor (type: WorkerType, filePath: string, opts: WorkerNodeOptions) {
  61     super()
  62     checkWorkerNodeArguments(type, filePath, opts)
  63     this.worker = createWorker<Worker>(type, filePath, {
  64       env: opts.env,
  65       workerOptions: opts.workerOptions
  66     })
  67     this.info = this.initWorkerInfo(this.worker)
  68     this.usage = this.initWorkerUsage()
  69     if (this.info.type === WorkerTypes.thread) {
  70       this.messageChannel = new MessageChannel()
  71     }
  72     // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
  73     this.tasksQueueBackPressureSize = opts.tasksQueueBackPressureSize!
  74     this.tasksQueue = new Deque<Task<Data>>()
  75     this.onBackPressureStarted = false
  76     this.taskFunctionsUsage = new Map<string, WorkerUsage>()
  77   }
  78
  79   /** @inheritdoc */
  80   public tasksQueueSize (): number {
  81     return this.tasksQueue.size
  82   }
  83
  84   /** @inheritdoc */
  85   public enqueueTask (task: Task<Data>): number {
  86     const tasksQueueSize = this.tasksQueue.push(task)
  87     if (this.hasBackPressure() && !this.onBackPressureStarted) {
  88       this.onBackPressureStarted = true
  89       this.emit('backPressure', { workerId: this.info.id })
  90       this.onBackPressureStarted = false
  91     }
  92     return tasksQueueSize
  93   }
  94
  95   /** @inheritdoc */
  96   public unshiftTask (task: Task<Data>): number {
  97     const tasksQueueSize = this.tasksQueue.unshift(task)
  98     if (this.hasBackPressure() && !this.onBackPressureStarted) {
  99       this.onBackPressureStarted = true
 100       this.emit('backPressure', { workerId: this.info.id })
 101       this.onBackPressureStarted = false
 102     }
 103     return tasksQueueSize
 104   }
 105
 106   /** @inheritdoc */
 107   public dequeueTask (): Task<Data> | undefined {
 108     return this.tasksQueue.shift()
 109   }
 110
 111   /** @inheritdoc */
 112   public popTask (): Task<Data> | undefined {
 113     return this.tasksQueue.pop()
 114   }
 115
 116   /** @inheritdoc */
 117   public clearTasksQueue (): void {
 118     this.tasksQueue.clear()
 119   }
 120
 121   /** @inheritdoc */
 122   public hasBackPressure (): boolean {
 123     return this.tasksQueue.size >= this.tasksQueueBackPressureSize
 124   }
 125
 126   /** @inheritdoc */
 127   public async terminate (): Promise<void> {
 128     const waitWorkerExit = new Promise<void>(resolve => {
 129       this.registerOnceWorkerEventHandler('exit', () => {
 130         resolve()
 131       })
 132     })
 133     this.closeMessageChannel()
 134     this.removeAllListeners()
 135     switch (this.info.type) {
 136       case WorkerTypes.thread:
 137         this.worker.unref?.()
 138         await this.worker.terminate?.()
 139         break
 140       case WorkerTypes.cluster:
 141         this.registerOnceWorkerEventHandler('disconnect', () => {
 142           this.worker.kill?.()
 143         })
 144         this.worker.disconnect?.()
 145         break
 146     }
 147     await waitWorkerExit
 148   }
 149
 150   /** @inheritdoc */
 151   public registerWorkerEventHandler (
 152     event: string,
 153     handler: EventHandler<Worker>
 154   ): void {
 155     this.worker.on(event, handler)
 156   }
 157
 158   /** @inheritdoc */
 159   public registerOnceWorkerEventHandler (
 160     event: string,
 161     handler: EventHandler<Worker>
 162   ): void {
 163     this.worker.once(event, handler)
 164   }
 165
 166   /** @inheritdoc */
 167   public getTaskFunctionWorkerUsage (name: string): WorkerUsage | undefined {
 168     if (!Array.isArray(this.info.taskFunctionsProperties)) {
 169       throw new Error(
 170         `Cannot get task function worker usage for task function name '${name}' when task function properties list is not yet defined`
 171       )
 172     }
 173     if (
 174       Array.isArray(this.info.taskFunctionsProperties) &&
 175       this.info.taskFunctionsProperties.length < 3
 176     ) {
 177       throw new Error(
 178         `Cannot get task function worker usage for task function name '${name}' when task function properties list has less than 3 elements`
 179       )
 180     }
 181     if (name === DEFAULT_TASK_NAME) {
 182       name = this.info.taskFunctionsProperties[1].name
 183     }
 184     if (!this.taskFunctionsUsage.has(name)) {
 185       this.taskFunctionsUsage.set(name, this.initTaskFunctionWorkerUsage(name))
 186     }
 187     return this.taskFunctionsUsage.get(name)
 188   }
 189
 190   /** @inheritdoc */
 191   public deleteTaskFunctionWorkerUsage (name: string): boolean {
 192     return this.taskFunctionsUsage.delete(name)
 193   }
 194
 195   private closeMessageChannel (): void {
 196     if (this.messageChannel != null) {
 197       this.messageChannel.port1.unref()
 198       this.messageChannel.port2.unref()
 199       this.messageChannel.port1.close()
 200       this.messageChannel.port2.close()
 201       delete this.messageChannel
 202     }
 203   }
 204
 205   private initWorkerInfo (worker: Worker): WorkerInfo {
 206     return {
 207       id: getWorkerId(worker),
 208       // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
 209       type: getWorkerType(worker)!,
 210       dynamic: false,
 211       ready: false,
 212       stealing: false
 213     }
 214   }
 215
 216   private initWorkerUsage (): WorkerUsage {
 217     const getTasksQueueSize = (): number => {
 218       return this.tasksQueue.size
 219     }
 220     const getTasksQueueMaxSize = (): number => {
 221       return this.tasksQueue.maxSize
 222     }
 223     return {
 224       tasks: {
 225         executed: 0,
 226         executing: 0,
 227         get queued (): number {
 228           return getTasksQueueSize()
 229         },
 230         get maxQueued (): number {
 231           return getTasksQueueMaxSize()
 232         },
 233         sequentiallyStolen: 0,
 234         stolen: 0,
 235         failed: 0
 236       },
 237       runTime: {
 238         history: new CircularArray<number>()
 239       },
 240       waitTime: {
 241         history: new CircularArray<number>()
 242       },
 243       elu: {
 244         idle: {
 245           history: new CircularArray<number>()
 246         },
 247         active: {
 248           history: new CircularArray<number>()
 249         }
 250       }
 251     }
 252   }
 253
 254   private initTaskFunctionWorkerUsage (name: string): WorkerUsage {
 255     const getTaskFunctionQueueSize = (): number => {
 256       let taskFunctionQueueSize = 0
 257       for (const task of this.tasksQueue) {
 258         if (
 259           (task.name === DEFAULT_TASK_NAME &&
 260             // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
 261             name === this.info.taskFunctionsProperties![1].name) ||
 262           (task.name !== DEFAULT_TASK_NAME && name === task.name)
 263         ) {
 264           ++taskFunctionQueueSize
 265         }
 266       }
 267       return taskFunctionQueueSize
 268     }
 269     return {
 270       tasks: {
 271         executed: 0,
 272         executing: 0,
 273         get queued (): number {
 274           return getTaskFunctionQueueSize()
 275         },
 276         sequentiallyStolen: 0,
 277         stolen: 0,
 278         failed: 0
 279       },
 280       runTime: {
 281         history: new CircularArray<number>()
 282       },
 283       waitTime: {
 284         history: new CircularArray<number>()
 285       },
 286       elu: {
 287         idle: {
 288           history: new CircularArray<number>()
 289         },
 290         active: {
 291           history: new CircularArray<number>()
 292         }
 293       }
 294     }
 295   }
 296 }