-import { DEFAULT_WORKER_CHOICE_STRATEGY_OPTIONS } from '../../utils'
-import type { IPool } from '../pool'
-import type { IWorker } from '../worker'
-import { AbstractWorkerChoiceStrategy } from './abstract-worker-choice-strategy'
-import type {
- IWorkerChoiceStrategy,
- RequiredStatistics,
- WorkerChoiceStrategyOptions
-} from './selection-strategies-types'
+import type { IPool } from '../pool.js'
+import type { IWorker } from '../worker.js'
+import { AbstractWorkerChoiceStrategy } from './abstract-worker-choice-strategy.js'
+import {
+ type IWorkerChoiceStrategy,
+ Measurements,
+ type TaskStatisticsRequirements,
+ type WorkerChoiceStrategyOptions
+} from './selection-strategies-types.js'
/**
* Selects the next worker with a fair share scheduling algorithm.
* Loosely modeled after the fair queueing algorithm: https://en.wikipedia.org/wiki/Fair_queuing.
*
* @typeParam Worker - Type of worker which manages the strategy.
- * @typeParam Data - Type of data sent to the worker. This can only be serializable data.
- * @typeParam Response - Type of execution response. This can only be serializable data.
+ * @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.
*/
export class FairShareWorkerChoiceStrategy<
Worker extends IWorker,
extends AbstractWorkerChoiceStrategy<Worker, Data, Response>
implements IWorkerChoiceStrategy {
/** @inheritDoc */
- public readonly requiredStatistics: RequiredStatistics = {
- runTime: true,
- avgRunTime: true,
- medRunTime: false,
- waitTime: false,
- avgWaitTime: false,
- medWaitTime: false,
- elu: false
+ public readonly taskStatisticsRequirements: TaskStatisticsRequirements = {
+ runTime: {
+ aggregate: true,
+ average: true,
+ median: false
+ },
+ waitTime: {
+ aggregate: true,
+ average: true,
+ median: false
+ },
+ elu: {
+ aggregate: true,
+ average: true,
+ median: false
+ }
}
- /**
- * Workers' virtual task end execution timestamp.
- */
- private workersVirtualTaskEndTimestamp: number[] = []
-
/** @inheritDoc */
public constructor (
pool: IPool<Worker, Data, Response>,
- opts: WorkerChoiceStrategyOptions = DEFAULT_WORKER_CHOICE_STRATEGY_OPTIONS
+ opts?: WorkerChoiceStrategyOptions
) {
super(pool, opts)
- this.setRequiredStatistics(this.opts)
+ this.setTaskStatisticsRequirements(this.opts)
}
/** @inheritDoc */
public reset (): boolean {
- this.workersVirtualTaskEndTimestamp = []
+ for (const workerNode of this.pool.workerNodes) {
+ delete workerNode.strategyData?.virtualTaskEndTimestamp
+ }
return true
}
/** @inheritDoc */
public update (workerNodeKey: number): boolean {
- this.computeWorkerVirtualTaskEndTimestamp(workerNodeKey)
+ this.pool.workerNodes[workerNodeKey].strategyData = {
+ virtualTaskEndTimestamp:
+ this.computeWorkerNodeVirtualTaskEndTimestamp(workerNodeKey)
+ }
return true
}
/** @inheritDoc */
- public choose (): number {
- let minWorkerVirtualTaskEndTimestamp = Infinity
- let chosenWorkerNodeKey!: number
- for (const [workerNodeKey] of this.pool.workerNodes.entries()) {
- if (this.workersVirtualTaskEndTimestamp[workerNodeKey] == null) {
- this.computeWorkerVirtualTaskEndTimestamp(workerNodeKey)
- }
- const workerVirtualTaskEndTimestamp =
- this.workersVirtualTaskEndTimestamp[workerNodeKey]
- if (workerVirtualTaskEndTimestamp < minWorkerVirtualTaskEndTimestamp) {
- minWorkerVirtualTaskEndTimestamp = workerVirtualTaskEndTimestamp
- chosenWorkerNodeKey = workerNodeKey
- }
- }
- return chosenWorkerNodeKey
+ public choose (): number | undefined {
+ this.setPreviousWorkerNodeKey(this.nextWorkerNodeKey)
+ this.nextWorkerNodeKey = this.fairShareNextWorkerNodeKey()
+ return this.nextWorkerNodeKey
}
/** @inheritDoc */
- public remove (workerNodeKey: number): boolean {
- this.workersVirtualTaskEndTimestamp.splice(workerNodeKey, 1)
+ public remove (): boolean {
return true
}
+ private fairShareNextWorkerNodeKey (): number | undefined {
+ if (this.pool.workerNodes.length === 0) {
+ return undefined
+ }
+ return this.pool.workerNodes.reduce(
+ (minWorkerNodeKey, workerNode, workerNodeKey, workerNodes) => {
+ if (workerNode.strategyData?.virtualTaskEndTimestamp == null) {
+ workerNode.strategyData = {
+ virtualTaskEndTimestamp:
+ this.computeWorkerNodeVirtualTaskEndTimestamp(workerNodeKey)
+ }
+ }
+ return this.isWorkerNodeReady(workerNodeKey) &&
+ // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
+ workerNode.strategyData.virtualTaskEndTimestamp! <
+ // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
+ workerNodes[minWorkerNodeKey].strategyData!.virtualTaskEndTimestamp!
+ ? workerNodeKey
+ : minWorkerNodeKey
+ },
+ 0
+ )
+ }
+
/**
* Computes the worker node key virtual task end timestamp.
*
* @param workerNodeKey - The worker node key.
+ * @returns The worker node key virtual task end timestamp.
*/
- private computeWorkerVirtualTaskEndTimestamp (workerNodeKey: number): void {
- this.workersVirtualTaskEndTimestamp[workerNodeKey] =
- this.getWorkerVirtualTaskEndTimestamp(
- workerNodeKey,
- this.getWorkerVirtualTaskStartTimestamp(workerNodeKey)
- )
+ private computeWorkerNodeVirtualTaskEndTimestamp (
+ workerNodeKey: number
+ ): number {
+ return this.getWorkerNodeVirtualTaskEndTimestamp(
+ workerNodeKey,
+ this.getWorkerNodeVirtualTaskStartTimestamp(workerNodeKey)
+ )
}
- private getWorkerVirtualTaskEndTimestamp (
+ private getWorkerNodeVirtualTaskEndTimestamp (
workerNodeKey: number,
- workerVirtualTaskStartTimestamp: number
+ workerNodeVirtualTaskStartTimestamp: number
): number {
- return (
- workerVirtualTaskStartTimestamp + this.getWorkerTaskRunTime(workerNodeKey)
- )
+ const workerNodeTaskExecutionTime =
+ this.getWorkerNodeTaskWaitTime(workerNodeKey) +
+ // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
+ (this.opts!.measurement === Measurements.elu
+ ? this.getWorkerNodeTaskElu(workerNodeKey)
+ : this.getWorkerNodeTaskRunTime(workerNodeKey))
+ return workerNodeVirtualTaskStartTimestamp + workerNodeTaskExecutionTime
}
- private getWorkerVirtualTaskStartTimestamp (workerNodeKey: number): number {
- return Math.max(
- performance.now(),
- this.workersVirtualTaskEndTimestamp[workerNodeKey] ?? -Infinity
- )
+ private getWorkerNodeVirtualTaskStartTimestamp (
+ workerNodeKey: number
+ ): number {
+ const virtualTaskEndTimestamp =
+ this.pool.workerNodes[workerNodeKey]?.strategyData
+ ?.virtualTaskEndTimestamp
+ const now = performance.now()
+ return now < (virtualTaskEndTimestamp ?? -Infinity)
+ ? // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
+ virtualTaskEndTimestamp!
+ : now
}
}