-import type { JSONValue, MessageValue } from '../../utility-types'
-import type { PoolOptions } from '../abstract-pool'
-import type { ThreadWorkerWithMessageChannel } from './fixed'
-import { FixedThreadPool } from './fixed'
+import { PoolEvents, type PoolType, PoolTypes } from '../pool.js'
+import { checkDynamicPoolSize } from '../utils.js'
+import { FixedThreadPool, type ThreadPoolOptions } from './fixed.js'
/**
* A thread pool with a dynamic number of threads, but a guaranteed minimum number of threads.
*
* This thread pool creates new threads when the others are busy, up to the maximum number of threads.
- * When the maximum number of threads is reached, an event is emitted. If you want to listen to this event, use the pool's `emitter`.
- *
- * @template Data Type of data sent to the worker.
- * @template Response Type of response of execution.
+ * When the maximum number of threads is reached and workers are busy, an event is emitted. If you want to listen to this event, use the pool's `emitter`.
*
+ * @typeParam Data - Type of data sent to the worker. This can only be structured-cloneable data.
+ * @typeParam Response - Type of execution response. This can only be structured-cloneable data.
* @author [Alessandro Pio Ardizio](https://github.com/pioardi)
* @since 0.0.1
*/
export class DynamicThreadPool<
- Data extends JSONValue = JSONValue,
- Response extends JSONValue = JSONValue
+ Data = unknown,
+ Response = unknown
> extends FixedThreadPool<Data, Response> {
/**
* Constructs a new poolifier dynamic thread pool.
*
- * @param min Minimum number of threads which are always active.
- * @param max Maximum number of threads that can be created by this pool.
- * @param filename Path to an implementation of a `ThreadWorker` file, which can be relative or absolute.
- * @param opts Options for this fixed thread pool. Default: `{ maxTasks: 1000 }`
+ * @param min - Minimum number of threads which are always active.
+ * @param max - Maximum number of threads that can be created by this pool.
+ * @param filePath - Path to an implementation of a `ThreadWorker` file, which can be relative or absolute.
+ * @param opts - Options for this dynamic thread pool.
*/
public constructor (
min: number,
- public readonly max: number,
- filename: string,
- opts: PoolOptions<ThreadWorkerWithMessageChannel> = { maxTasks: 1000 }
+ max: number,
+ filePath: string,
+ opts: ThreadPoolOptions = {}
) {
- super(min, filename, opts)
+ super(min, filePath, opts, max)
+ checkDynamicPoolSize(
+ this.minimumNumberOfWorkers,
+ this.maximumNumberOfWorkers
+ )
}
- /**
- * Choose a thread for the next task.
- *
- * It will first check for and return an idle thread.
- * If all threads are busy, then it will try to create a new one up to the `max` thread count.
- * If the max thread count is reached, the emitter will emit a `FullPool` event and it will fall back to using a round robin algorithm to distribute the load.
- */
- protected chooseWorker (): ThreadWorkerWithMessageChannel {
- let worker: ThreadWorkerWithMessageChannel | undefined
- for (const entry of this.tasks) {
- if (entry[1] === 0) {
- worker = entry[0]
- break
- }
- }
+ /** @inheritDoc */
+ protected shallCreateDynamicWorker (): boolean {
+ return (!this.full && this.internalBusy()) || this.empty
+ }
- if (worker) {
- // a worker is free, use it
- return worker
- } else {
- if (this.workers.length === this.max) {
- this.emitter.emit('FullPool')
- return super.chooseWorker()
- }
- // all workers are busy create a new worker
- const worker = this.internalNewWorker()
- worker.port2?.on('message', (message: MessageValue<Data>) => {
- if (message.kill) {
- this.sendToWorker(worker, { kill: 1 })
- void this.destroyWorker(worker)
- this.removeWorker(worker)
- }
- })
- return worker
+ /** @inheritDoc */
+ protected checkAndEmitDynamicWorkerCreationEvents (): void {
+ if (this.full) {
+ this.emitter?.emit(PoolEvents.full, this.info)
}
}
+
+ /** @inheritDoc */
+ protected get type (): PoolType {
+ return PoolTypes.dynamic
+ }
+
+ /** @inheritDoc */
+ protected get busy (): boolean {
+ return this.full && this.internalBusy()
+ }
}