-import { DEFAULT_WORKER_CHOICE_STRATEGY_OPTIONS } from '../../utils'
+import {
+ DEFAULT_MEASUREMENT_STATISTICS_REQUIREMENTS,
+ 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
+import {
+ type IWorkerChoiceStrategy,
+ Measurements,
+ type TaskStatisticsRequirements,
+ type WorkerChoiceStrategyOptions
} from './selection-strategies-types'
-/**
- * Worker virtual task timestamp.
- */
-interface WorkerVirtualTaskTimestamp {
- start: number
- end: number
-}
-
/**
* 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
+ public readonly taskStatisticsRequirements: TaskStatisticsRequirements = {
+ runTime: {
+ aggregate: true,
+ average: true,
+ median: false
+ },
+ waitTime: DEFAULT_MEASUREMENT_STATISTICS_REQUIREMENTS,
+ elu: {
+ aggregate: true,
+ average: true,
+ median: false
+ }
}
/**
- * Worker last virtual task execution timestamp.
+ * Workers' virtual task end execution timestamp.
*/
- private readonly workerLastVirtualTaskTimestamp: Map<
- number,
- WorkerVirtualTaskTimestamp
- > = new Map<number, WorkerVirtualTaskTimestamp>()
+ private workersVirtualTaskEndTimestamp: number[] = []
/** @inheritDoc */
public constructor (
opts: WorkerChoiceStrategyOptions = DEFAULT_WORKER_CHOICE_STRATEGY_OPTIONS
) {
super(pool, opts)
- this.checkOptions(this.opts)
+ this.setTaskStatisticsRequirements(this.opts)
}
/** @inheritDoc */
public reset (): boolean {
- this.workerLastVirtualTaskTimestamp.clear()
+ this.workersVirtualTaskEndTimestamp = []
+ return true
+ }
+
+ /** @inheritDoc */
+ public update (workerNodeKey: number): boolean {
+ this.computeWorkerVirtualTaskEndTimestamp(workerNodeKey)
return true
}
/** @inheritDoc */
public choose (): number {
- let minWorkerVirtualTaskEndTimestamp = Infinity
- let chosenWorkerNodeKey!: number
- for (const [index] of this.pool.workerNodes.entries()) {
- this.computeWorkerLastVirtualTaskTimestamp(index)
- const workerLastVirtualTaskEndTimestamp =
- this.workerLastVirtualTaskTimestamp.get(index)?.end ?? 0
- if (
- workerLastVirtualTaskEndTimestamp < minWorkerVirtualTaskEndTimestamp
- ) {
- minWorkerVirtualTaskEndTimestamp = workerLastVirtualTaskEndTimestamp
- chosenWorkerNodeKey = index
- }
- }
- return chosenWorkerNodeKey
+ return this.fairShareNextWorkerNodeKey()
}
/** @inheritDoc */
public remove (workerNodeKey: number): boolean {
- const deleted = this.workerLastVirtualTaskTimestamp.delete(workerNodeKey)
- for (const [key, value] of this.workerLastVirtualTaskTimestamp) {
- if (key > workerNodeKey) {
- this.workerLastVirtualTaskTimestamp.set(key - 1, value)
+ this.workersVirtualTaskEndTimestamp.splice(workerNodeKey, 1)
+ return true
+ }
+
+ private fairShareNextWorkerNodeKey (): number {
+ let minWorkerVirtualTaskEndTimestamp = Infinity
+ for (const [workerNodeKey] of this.pool.workerNodes.entries()) {
+ if (this.workersVirtualTaskEndTimestamp[workerNodeKey] == null) {
+ this.computeWorkerVirtualTaskEndTimestamp(workerNodeKey)
+ }
+ const workerVirtualTaskEndTimestamp =
+ this.workersVirtualTaskEndTimestamp[workerNodeKey]
+ if (
+ this.isWorkerNodeEligible(workerNodeKey) &&
+ workerVirtualTaskEndTimestamp < minWorkerVirtualTaskEndTimestamp
+ ) {
+ minWorkerVirtualTaskEndTimestamp = workerVirtualTaskEndTimestamp
+ this.nextWorkerNodeKey = workerNodeKey
}
}
- return deleted
+ return this.nextWorkerNodeKey
}
/**
- * Computes worker last virtual task timestamp.
+ * Computes the worker node key virtual task end timestamp.
*
* @param workerNodeKey - The worker node key.
*/
- private computeWorkerLastVirtualTaskTimestamp (workerNodeKey: number): void {
- const workerVirtualTaskStartTimestamp = Math.max(
+ private computeWorkerVirtualTaskEndTimestamp (workerNodeKey: number): void {
+ this.workersVirtualTaskEndTimestamp[workerNodeKey] =
+ this.getWorkerVirtualTaskEndTimestamp(
+ workerNodeKey,
+ this.getWorkerVirtualTaskStartTimestamp(workerNodeKey)
+ )
+ }
+
+ private getWorkerVirtualTaskEndTimestamp (
+ workerNodeKey: number,
+ workerVirtualTaskStartTimestamp: number
+ ): number {
+ const workerTaskRunTime =
+ this.opts.measurement === Measurements.elu
+ ? this.getWorkerTaskElu(workerNodeKey)
+ : this.getWorkerTaskRunTime(workerNodeKey)
+ return workerVirtualTaskStartTimestamp + workerTaskRunTime
+ }
+
+ private getWorkerVirtualTaskStartTimestamp (workerNodeKey: number): number {
+ return Math.max(
performance.now(),
- this.workerLastVirtualTaskTimestamp.get(workerNodeKey)?.end ?? -Infinity
+ this.workersVirtualTaskEndTimestamp[workerNodeKey] ?? -Infinity
)
- const workerVirtualTaskTRunTime = this.requiredStatistics.medRunTime
- ? this.pool.workerNodes[workerNodeKey].tasksUsage.medRunTime
- : this.pool.workerNodes[workerNodeKey].tasksUsage.avgRunTime
- this.workerLastVirtualTaskTimestamp.set(workerNodeKey, {
- start: workerVirtualTaskStartTimestamp,
- end: workerVirtualTaskStartTimestamp + (workerVirtualTaskTRunTime ?? 0)
- })
}
}