| 1 | import { isMainThread, MessageChannel, SHARE_ENV, Worker } from 'worker_threads' |
| 2 | import type { Draft, MessageValue } from '../../utility-types' |
| 3 | import type { PoolOptions } from '../abstract-pool' |
| 4 | import { AbstractPool } from '../abstract-pool' |
| 5 | |
| 6 | export type ThreadWorkerWithMessageChannel = Worker & Draft<MessageChannel> |
| 7 | |
| 8 | /** |
| 9 | * A thread pool with a static number of threads, is possible to execute tasks in sync or async mode as you prefer. |
| 10 | * |
| 11 | * This pool will select the worker thread in a round robin fashion. |
| 12 | * |
| 13 | * @author [Alessandro Pio Ardizio](https://github.com/pioardi) |
| 14 | * @since 0.0.1 |
| 15 | */ |
| 16 | // eslint-disable-next-line @typescript-eslint/no-explicit-any |
| 17 | export class FixedThreadPool<Data = any, Response = any> extends AbstractPool< |
| 18 | ThreadWorkerWithMessageChannel, |
| 19 | Data, |
| 20 | Response |
| 21 | > { |
| 22 | /** |
| 23 | * @param numThreads Num of threads for this worker pool. |
| 24 | * @param filePath A file path with implementation of `ThreadWorker` class, relative path is fine. |
| 25 | * @param opts An object with possible options for example `errorHandler`, `onlineHandler`. Default: `{ maxTasks: 1000 }` |
| 26 | */ |
| 27 | public constructor ( |
| 28 | numThreads: number, |
| 29 | filePath: string, |
| 30 | opts: PoolOptions<ThreadWorkerWithMessageChannel> = { maxTasks: 1000 } |
| 31 | ) { |
| 32 | super(numThreads, filePath, opts) |
| 33 | } |
| 34 | |
| 35 | protected isMain (): boolean { |
| 36 | return isMainThread |
| 37 | } |
| 38 | |
| 39 | protected async destroyWorker ( |
| 40 | worker: ThreadWorkerWithMessageChannel |
| 41 | ): Promise<void> { |
| 42 | await worker.terminate() |
| 43 | } |
| 44 | |
| 45 | protected sendToWorker ( |
| 46 | worker: ThreadWorkerWithMessageChannel, |
| 47 | message: MessageValue<Data> |
| 48 | ): void { |
| 49 | worker.postMessage(message) |
| 50 | } |
| 51 | |
| 52 | protected registerWorkerMessageListener ( |
| 53 | port: ThreadWorkerWithMessageChannel, |
| 54 | listener: (message: MessageValue<Response>) => void |
| 55 | ): void { |
| 56 | port.port2?.on('message', listener) |
| 57 | } |
| 58 | |
| 59 | protected unregisterWorkerMessageListener ( |
| 60 | port: ThreadWorkerWithMessageChannel, |
| 61 | listener: (message: MessageValue<Response>) => void |
| 62 | ): void { |
| 63 | port.port2?.removeListener('message', listener) |
| 64 | } |
| 65 | |
| 66 | protected newWorker (): ThreadWorkerWithMessageChannel { |
| 67 | return new Worker(this.filePath, { |
| 68 | env: SHARE_ENV |
| 69 | }) |
| 70 | } |
| 71 | |
| 72 | protected afterNewWorkerPushed ( |
| 73 | worker: ThreadWorkerWithMessageChannel |
| 74 | ): void { |
| 75 | const { port1, port2 } = new MessageChannel() |
| 76 | worker.postMessage({ parent: port1 }, [port1]) |
| 77 | worker.port1 = port1 |
| 78 | worker.port2 = port2 |
| 79 | // we will attach a listener for every task, |
| 80 | // when task is completed the listener will be removed but to avoid warnings we are increasing the max listeners size |
| 81 | worker.port2.setMaxListeners(this.opts.maxTasks ?? 1000) |
| 82 | } |
| 83 | } |