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.on('exit', () => {
  67         resolve()
  68       })
  69     })
  70     await this.sendKillMessageToWorker(
  71       workerNodeKey,
  72       workerNode.info.id as number
  73     )
  74     workerNode.closeChannel()
  75     await worker.terminate()
  76     await waitWorkerExit
  77   }
  78
  79   /** @inheritDoc */
  80   protected sendToWorker (
  81     workerNodeKey: number,
  82     message: MessageValue<Data>,
  83     transferList?: TransferListItem[]
  84   ): void {
  85     (
  86       this.workerNodes[workerNodeKey].messageChannel as MessageChannel
  87     ).port1.postMessage(message, transferList)
  88   }
  89
  90   /** @inheritDoc */
  91   protected sendStartupMessageToWorker (workerNodeKey: number): void {
  92     const workerNode = this.workerNodes[workerNodeKey]
  93     const worker = workerNode.worker
  94     const port2: MessagePort = (workerNode.messageChannel as MessageChannel)
  95       .port2
  96     worker.postMessage(
  97       {
  98         ready: false,
  99         workerId: workerNode.info.id,
 100         port: port2
 101       },
 102       [port2]
 103     )
 104   }
 105
 106   /** @inheritDoc */
 107   protected registerWorkerMessageListener<Message extends Data | Response>(
 108     workerNodeKey: number,
 109     listener: (message: MessageValue<Message>) => void
 110   ): void {
 111     (
 112       this.workerNodes[workerNodeKey].messageChannel as MessageChannel
 113     ).port1.on('message', listener)
 114   }
 115
 116   /** @inheritDoc */
 117   protected createWorker (): Worker {
 118     return new Worker(this.filePath, {
 119       env: SHARE_ENV,
 120       ...this.opts.workerOptions
 121     })
 122   }
 123
 124   /** @inheritDoc */
 125   protected get type (): PoolType {
 126     return PoolTypes.fixed
 127   }
 128
 129   /** @inheritDoc */
 130   protected get worker (): WorkerType {
 131     return WorkerTypes.thread
 132   }
 133
 134   /** @inheritDoc */
 135   protected get busy (): boolean {
 136     return this.internalBusy()
 137   }
 138 }