src/pools/thread/fixed.ts

   1 import {
   2   type MessageChannel,
   3   type MessagePort,
   4   SHARE_ENV,
   5   type TransferListItem,
   6   Worker,
   7   type WorkerOptions,
   8   isMainThread
   9 } from 'node:worker_threads'
  10 import type { MessageValue } from '../../utility-types'
  11 import { AbstractPool } from '../abstract-pool'
  12 import { type PoolOptions, type PoolType, PoolTypes } from '../pool'
  13 import { type WorkerType, WorkerTypes } from '../worker'
  14
  15 /**
  16  * Options for a poolifier thread pool.
  17  */
  18 export interface ThreadPoolOptions extends PoolOptions<Worker> {
  19   /**
  20    * Worker options.
  21    *
  22    * @see https://nodejs.org/api/worker_threads.html#new-workerfilename-options
  23    */
  24   workerOptions?: WorkerOptions
  25 }
  26
  27 /**
  28  * A thread pool with a fixed number of threads.
  29  *
  30  * @typeParam Data - Type of data sent to the worker. This can only be structured-cloneable data.
  31  * @typeParam Response - Type of execution response. This can only be structured-cloneable data.
  32  * @author [Alessandro Pio Ardizio](https://github.com/pioardi)
  33  * @since 0.0.1
  34  */
  35 export class FixedThreadPool<
  36   Data = unknown,
  37   Response = unknown
  38 > extends AbstractPool<Worker, Data, Response> {
  39   /**
  40    * Constructs a new poolifier fixed thread pool.
  41    *
  42    * @param numberOfThreads - Number of threads for this pool.
  43    * @param filePath - Path to an implementation of a `ThreadWorker` file, which can be relative or absolute.
  44    * @param opts - Options for this fixed thread pool.
  45    */
  46   public constructor (
  47     numberOfThreads: number,
  48     filePath: string,
  49     protected readonly opts: ThreadPoolOptions = {}
  50   ) {
  51     super(numberOfThreads, filePath, opts)
  52   }
  53
  54   /** @inheritDoc */
  55   protected isMain (): boolean {
  56     return isMainThread
  57   }
  58
  59   /** @inheritDoc */
  60   protected async destroyWorkerNode (workerNodeKey: number): Promise<void> {
  61     this.flushTasksQueue(workerNodeKey)
  62     // FIXME: wait for tasks to be finished
  63     const workerNode = this.workerNodes[workerNodeKey]
  64     const worker = workerNode.worker
  65     const waitWorkerExit = new Promise<void>(resolve => {
  66       worker.once('exit', () => {
  67         resolve()
  68       })
  69     })
  70     await this.sendKillMessageToWorker(workerNodeKey)
  71     workerNode.closeChannel()
  72     await worker.terminate()
  73     await waitWorkerExit
  74   }
  75
  76   /** @inheritDoc */
  77   protected sendToWorker (
  78     workerNodeKey: number,
  79     message: MessageValue<Data>,
  80     transferList?: TransferListItem[]
  81   ): void {
  82     (
  83       this.workerNodes[workerNodeKey].messageChannel as MessageChannel
  84     ).port1.postMessage(
  85       { ...message, workerId: this.workerNodes[workerNodeKey].info.id },
  86       transferList
  87     )
  88   }
  89
  90   /** @inheritDoc */
  91   protected sendStartupMessageToWorker (workerNodeKey: number): void {
  92     const workerNode = this.workerNodes[workerNodeKey]
  93     const port2: MessagePort = (workerNode.messageChannel as MessageChannel)
  94       .port2
  95     workerNode.worker.postMessage(
  96       {
  97         ready: false,
  98         workerId: workerNode.info.id,
  99         port: port2
 100       },
 101       [port2]
 102     )
 103   }
 104
 105   /** @inheritDoc */
 106   protected registerWorkerMessageListener<Message extends Data | Response>(
 107     workerNodeKey: number,
 108     listener: (message: MessageValue<Message>) => void
 109   ): void {
 110     (
 111       this.workerNodes[workerNodeKey].messageChannel as MessageChannel
 112     ).port1.on('message', listener)
 113   }
 114
 115   /** @inheritDoc */
 116   protected registerOnceWorkerMessageListener<Message extends Data | Response>(
 117     workerNodeKey: number,
 118     listener: (message: MessageValue<Message>) => void
 119   ): void {
 120     (
 121       this.workerNodes[workerNodeKey].messageChannel as MessageChannel
 122     ).port1.once('message', listener)
 123   }
 124
 125   /** @inheritDoc */
 126   protected deregisterWorkerMessageListener<Message extends Data | Response>(
 127     workerNodeKey: number,
 128     listener: (message: MessageValue<Message>) => void
 129   ): void {
 130     (
 131       this.workerNodes[workerNodeKey].messageChannel as MessageChannel
 132     ).port1.off('message', listener)
 133   }
 134
 135   /** @inheritDoc */
 136   protected createWorker (): Worker {
 137     return new Worker(this.filePath, {
 138       env: SHARE_ENV,
 139       ...this.opts.workerOptions
 140     })
 141   }
 142
 143   /** @inheritDoc */
 144   protected get type (): PoolType {
 145     return PoolTypes.fixed
 146   }
 147
 148   /** @inheritDoc */
 149   protected get worker (): WorkerType {
 150     return WorkerTypes.thread
 151   }
 152
 153   /** @inheritDoc */
 154   protected get busy (): boolean {
 155     return this.internalBusy()
 156   }
 157 }