| 1 | import { isMainThread, MessageChannel, SHARE_ENV, Worker } from 'worker_threads' |
| 2 | import type { Draft, JSONValue, MessageValue } from '../../utility-types' |
| 3 | import type { PoolOptions } from '../abstract-pool' |
| 4 | import { AbstractPool } from '../abstract-pool' |
| 5 | |
| 6 | /** |
| 7 | * A thread worker with message channels for communication between main thread and thread worker. |
| 8 | */ |
| 9 | export type ThreadWorkerWithMessageChannel = Worker & Draft<MessageChannel> |
| 10 | |
| 11 | /** |
| 12 | * A thread pool with a fixed number of threads. |
| 13 | * |
| 14 | * It is possible to perform tasks in sync or asynchronous mode as you prefer. |
| 15 | * |
| 16 | * This pool selects the threads in a round robin fashion. |
| 17 | * |
| 18 | * @template Data Type of data sent to the worker. |
| 19 | * @template Response Type of response of execution. |
| 20 | * |
| 21 | * @author [Alessandro Pio Ardizio](https://github.com/pioardi) |
| 22 | * @since 0.0.1 |
| 23 | */ |
| 24 | export class FixedThreadPool< |
| 25 | Data extends JSONValue = JSONValue, |
| 26 | Response extends JSONValue = JSONValue |
| 27 | > extends AbstractPool<ThreadWorkerWithMessageChannel, Data, Response> { |
| 28 | /** |
| 29 | * Constructs a new poolifier fixed thread pool. |
| 30 | * |
| 31 | * @param numberOfThreads Number of threads for this pool. |
| 32 | * @param filePath Path to an implementation of a `ThreadWorker` file, which can be relative or absolute. |
| 33 | * @param opts Options for this fixed thread pool. Default: `{ maxTasks: 1000 }` |
| 34 | */ |
| 35 | public constructor ( |
| 36 | numberOfThreads: number, |
| 37 | filePath: string, |
| 38 | opts: PoolOptions<ThreadWorkerWithMessageChannel> = { maxTasks: 1000 } |
| 39 | ) { |
| 40 | super(numberOfThreads, filePath, opts) |
| 41 | } |
| 42 | |
| 43 | protected isMain (): boolean { |
| 44 | return isMainThread |
| 45 | } |
| 46 | |
| 47 | protected async destroyWorker ( |
| 48 | worker: ThreadWorkerWithMessageChannel |
| 49 | ): Promise<void> { |
| 50 | await worker.terminate() |
| 51 | } |
| 52 | |
| 53 | protected sendToWorker ( |
| 54 | worker: ThreadWorkerWithMessageChannel, |
| 55 | message: MessageValue<Data> |
| 56 | ): void { |
| 57 | worker.postMessage(message) |
| 58 | } |
| 59 | |
| 60 | protected registerWorkerMessageListener<Message extends Data | Response> ( |
| 61 | messageChannel: ThreadWorkerWithMessageChannel, |
| 62 | listener: (message: MessageValue<Message>) => void |
| 63 | ): void { |
| 64 | messageChannel.port2?.on('message', listener) |
| 65 | } |
| 66 | |
| 67 | protected unregisterWorkerMessageListener<Message extends Data | Response> ( |
| 68 | messageChannel: ThreadWorkerWithMessageChannel, |
| 69 | listener: (message: MessageValue<Message>) => void |
| 70 | ): void { |
| 71 | messageChannel.port2?.removeListener('message', listener) |
| 72 | } |
| 73 | |
| 74 | protected createWorker (): ThreadWorkerWithMessageChannel { |
| 75 | return new Worker(this.filePath, { |
| 76 | env: SHARE_ENV |
| 77 | }) |
| 78 | } |
| 79 | |
| 80 | protected afterWorkerSetup (worker: ThreadWorkerWithMessageChannel): void { |
| 81 | const { port1, port2 } = new MessageChannel() |
| 82 | worker.postMessage({ parent: port1 }, [port1]) |
| 83 | worker.port1 = port1 |
| 84 | worker.port2 = port2 |
| 85 | // we will attach a listener for every task, |
| 86 | // when task is completed the listener will be removed but to avoid warnings we are increasing the max listeners size |
| 87 | worker.port2.setMaxListeners(this.opts.maxTasks ?? 1000) |
| 88 | } |
| 89 | } |