1 import { randomUUID
} from
'node:crypto'
2 import { performance
} from
'node:perf_hooks'
3 import type { TransferListItem
} from
'node:worker_threads'
4 import { EventEmitterAsyncResource
} from
'node:events'
5 import { AsyncResource
} from
'node:async_hooks'
8 PromiseResponseWrapper
,
10 } from
'../utility-types.js'
24 import { KillBehaviors
} from
'../worker/worker-options.js'
25 import type { TaskFunction
} from
'../worker/task-functions.js'
33 type TasksQueueOptions
39 WorkerNodeEventDetail
,
44 WorkerChoiceStrategies
,
45 type WorkerChoiceStrategy
,
46 type WorkerChoiceStrategyOptions
47 } from
'./selection-strategies/selection-strategies-types.js'
48 import { WorkerChoiceStrategyContext
} from
'./selection-strategies/worker-choice-strategy-context.js'
49 import { version
} from
'./version.js'
50 import { WorkerNode
} from
'./worker-node.js'
53 checkValidTasksQueueOptions
,
54 checkValidWorkerChoiceStrategy
,
55 getDefaultTasksQueueOptions
,
57 updateRunTimeWorkerUsage
,
58 updateTaskStatisticsWorkerUsage
,
59 updateWaitTimeWorkerUsage
,
64 * Base class that implements some shared logic for all poolifier pools.
66 * @typeParam Worker - Type of worker which manages this pool.
67 * @typeParam Data - Type of data sent to the worker. This can only be structured-cloneable data.
68 * @typeParam Response - Type of execution response. This can only be structured-cloneable data.
70 export abstract class AbstractPool
<
71 Worker
extends IWorker
,
74 > implements IPool
<Worker
, Data
, Response
> {
76 public readonly workerNodes
: Array<IWorkerNode
<Worker
, Data
>> = []
79 public emitter
?: EventEmitterAsyncResource
82 * The task execution response promise map:
83 * - `key`: The message id of each submitted task.
84 * - `value`: An object that contains the worker, the execution response promise resolve and reject callbacks.
86 * When we receive a message from the worker, we get a map entry with the promise resolve/reject bound to the message id.
88 protected promiseResponseMap
: Map
<string, PromiseResponseWrapper
<Response
>> =
89 new Map
<string, PromiseResponseWrapper
<Response
>>()
92 * Worker choice strategy context referencing a worker choice algorithm implementation.
94 protected workerChoiceStrategyContext
?: WorkerChoiceStrategyContext
<
101 * The task functions added at runtime map:
102 * - `key`: The task function name.
103 * - `value`: The task function itself.
105 private readonly taskFunctions
: Map
<string, TaskFunction
<Data
, Response
>>
108 * Whether the pool is started or not.
110 private started
: boolean
112 * Whether the pool is starting or not.
114 private starting
: boolean
116 * Whether the pool is destroying or not.
118 private destroying
: boolean
120 * Whether the pool ready event has been emitted or not.
122 private readyEventEmitted
: boolean
124 * The start timestamp of the pool.
126 private readonly startTimestamp
129 * Constructs a new poolifier pool.
131 * @param minimumNumberOfWorkers - Minimum number of workers that this pool manages.
132 * @param filePath - Path to the worker file.
133 * @param opts - Options for the pool.
134 * @param maximumNumberOfWorkers - Maximum number of workers that this pool manages.
137 protected readonly minimumNumberOfWorkers
: number,
138 protected readonly filePath
: string,
139 protected readonly opts
: PoolOptions
<Worker
>,
140 protected readonly maximumNumberOfWorkers
?: number
142 if (!this.isMain()) {
144 'Cannot start a pool from a worker with the same type as the pool'
148 checkFilePath(this.filePath
)
149 this.checkMinimumNumberOfWorkers(this.minimumNumberOfWorkers
)
150 this.checkPoolOptions(this.opts
)
152 this.chooseWorkerNode
= this.chooseWorkerNode
.bind(this)
153 this.executeTask
= this.executeTask
.bind(this)
154 this.enqueueTask
= this.enqueueTask
.bind(this)
156 if (this.opts
.enableEvents
=== true) {
157 this.initializeEventEmitter()
159 this.workerChoiceStrategyContext
= new WorkerChoiceStrategyContext
<
165 this.opts
.workerChoiceStrategy
,
166 this.opts
.workerChoiceStrategyOptions
171 this.taskFunctions
= new Map
<string, TaskFunction
<Data
, Response
>>()
174 this.starting
= false
175 this.destroying
= false
176 this.readyEventEmitted
= false
177 if (this.opts
.startWorkers
=== true) {
181 this.startTimestamp
= performance
.now()
184 private checkPoolType (): void {
185 if (this.type === PoolTypes
.fixed
&& this.maximumNumberOfWorkers
!= null) {
187 'Cannot instantiate a fixed pool with a maximum number of workers specified at initialization'
192 private checkMinimumNumberOfWorkers (
193 minimumNumberOfWorkers
: number | undefined
195 if (minimumNumberOfWorkers
== null) {
197 'Cannot instantiate a pool without specifying the number of workers'
199 } else if (!Number.isSafeInteger(minimumNumberOfWorkers
)) {
201 'Cannot instantiate a pool with a non safe integer number of workers'
203 } else if (minimumNumberOfWorkers
< 0) {
204 throw new RangeError(
205 'Cannot instantiate a pool with a negative number of workers'
207 } else if (this.type === PoolTypes
.fixed
&& minimumNumberOfWorkers
=== 0) {
208 throw new RangeError('Cannot instantiate a fixed pool with zero worker')
212 private checkPoolOptions (opts
: PoolOptions
<Worker
>): void {
213 if (isPlainObject(opts
)) {
214 this.opts
.startWorkers
= opts
.startWorkers
?? true
215 checkValidWorkerChoiceStrategy(opts
.workerChoiceStrategy
)
216 this.opts
.workerChoiceStrategy
=
217 opts
.workerChoiceStrategy
?? WorkerChoiceStrategies
.ROUND_ROBIN
218 this.checkValidWorkerChoiceStrategyOptions(
219 opts
.workerChoiceStrategyOptions
221 if (opts
.workerChoiceStrategyOptions
!= null) {
222 this.opts
.workerChoiceStrategyOptions
= opts
.workerChoiceStrategyOptions
224 this.opts
.restartWorkerOnError
= opts
.restartWorkerOnError
?? true
225 this.opts
.enableEvents
= opts
.enableEvents
?? true
226 this.opts
.enableTasksQueue
= opts
.enableTasksQueue
?? false
227 if (this.opts
.enableTasksQueue
) {
228 checkValidTasksQueueOptions(opts
.tasksQueueOptions
)
229 this.opts
.tasksQueueOptions
= this.buildTasksQueueOptions(
230 opts
.tasksQueueOptions
234 throw new TypeError('Invalid pool options: must be a plain object')
238 private checkValidWorkerChoiceStrategyOptions (
239 workerChoiceStrategyOptions
: WorkerChoiceStrategyOptions
| undefined
242 workerChoiceStrategyOptions
!= null &&
243 !isPlainObject(workerChoiceStrategyOptions
)
246 'Invalid worker choice strategy options: must be a plain object'
250 workerChoiceStrategyOptions
?.weights
!= null &&
251 Object.keys(workerChoiceStrategyOptions
.weights
).length
!==
252 (this.maximumNumberOfWorkers
?? this.minimumNumberOfWorkers
)
255 'Invalid worker choice strategy options: must have a weight for each worker node'
259 workerChoiceStrategyOptions
?.measurement
!= null &&
260 !Object.values(Measurements
).includes(
261 workerChoiceStrategyOptions
.measurement
265 `Invalid worker choice strategy options: invalid measurement '${workerChoiceStrategyOptions.measurement}'`
270 private initializeEventEmitter (): void {
271 this.emitter
= new EventEmitterAsyncResource({
272 name
: `poolifier:${this.type}-${this.worker}-pool`
277 public get
info (): PoolInfo
{
282 started
: this.started
,
284 // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
285 strategy
: this.opts
.workerChoiceStrategy
!,
286 minSize
: this.minimumNumberOfWorkers
,
287 maxSize
: this.maximumNumberOfWorkers
?? this.minimumNumberOfWorkers
,
288 ...(this.workerChoiceStrategyContext
?.getTaskStatisticsRequirements()
289 ?.runTime
.aggregate
=== true &&
290 this.workerChoiceStrategyContext
.getTaskStatisticsRequirements()
291 .waitTime
.aggregate
&& {
292 utilization
: round(this.utilization
)
294 workerNodes
: this.workerNodes
.length
,
295 idleWorkerNodes
: this.workerNodes
.reduce(
296 (accumulator
, workerNode
) =>
297 workerNode
.usage
.tasks
.executing
=== 0
302 ...(this.opts
.enableTasksQueue
=== true && {
303 stealingWorkerNodes
: this.workerNodes
.reduce(
304 (accumulator
, workerNode
) =>
305 workerNode
.info
.stealing
? accumulator
+ 1 : accumulator
,
309 busyWorkerNodes
: this.workerNodes
.reduce(
310 (accumulator
, _workerNode
, workerNodeKey
) =>
311 this.isWorkerNodeBusy(workerNodeKey
) ? accumulator
+ 1 : accumulator
,
314 executedTasks
: this.workerNodes
.reduce(
315 (accumulator
, workerNode
) =>
316 accumulator
+ workerNode
.usage
.tasks
.executed
,
319 executingTasks
: this.workerNodes
.reduce(
320 (accumulator
, workerNode
) =>
321 accumulator
+ workerNode
.usage
.tasks
.executing
,
324 ...(this.opts
.enableTasksQueue
=== true && {
325 queuedTasks
: this.workerNodes
.reduce(
326 (accumulator
, workerNode
) =>
327 accumulator
+ workerNode
.usage
.tasks
.queued
,
331 ...(this.opts
.enableTasksQueue
=== true && {
332 maxQueuedTasks
: this.workerNodes
.reduce(
333 (accumulator
, workerNode
) =>
334 accumulator
+ (workerNode
.usage
.tasks
.maxQueued
?? 0),
338 ...(this.opts
.enableTasksQueue
=== true && {
339 backPressure
: this.hasBackPressure()
341 ...(this.opts
.enableTasksQueue
=== true && {
342 stolenTasks
: this.workerNodes
.reduce(
343 (accumulator
, workerNode
) =>
344 accumulator
+ workerNode
.usage
.tasks
.stolen
,
348 failedTasks
: this.workerNodes
.reduce(
349 (accumulator
, workerNode
) =>
350 accumulator
+ workerNode
.usage
.tasks
.failed
,
353 ...(this.workerChoiceStrategyContext
?.getTaskStatisticsRequirements()
354 ?.runTime
.aggregate
=== true && {
358 ...this.workerNodes
.map(
359 workerNode
=> workerNode
.usage
.runTime
.minimum
?? Infinity
365 ...this.workerNodes
.map(
366 workerNode
=> workerNode
.usage
.runTime
.maximum
?? -Infinity
370 ...(this.workerChoiceStrategyContext
.getTaskStatisticsRequirements()
371 .runTime
.average
&& {
374 this.workerNodes
.reduce
<number[]>(
375 (accumulator
, workerNode
) =>
376 accumulator
.concat(workerNode
.usage
.runTime
.history
),
382 ...(this.workerChoiceStrategyContext
.getTaskStatisticsRequirements()
386 this.workerNodes
.reduce
<number[]>(
387 (accumulator
, workerNode
) =>
388 accumulator
.concat(workerNode
.usage
.runTime
.history
),
396 ...(this.workerChoiceStrategyContext
?.getTaskStatisticsRequirements()
397 ?.waitTime
.aggregate
=== true && {
401 ...this.workerNodes
.map(
402 workerNode
=> workerNode
.usage
.waitTime
.minimum
?? Infinity
408 ...this.workerNodes
.map(
409 workerNode
=> workerNode
.usage
.waitTime
.maximum
?? -Infinity
413 ...(this.workerChoiceStrategyContext
.getTaskStatisticsRequirements()
414 .waitTime
.average
&& {
417 this.workerNodes
.reduce
<number[]>(
418 (accumulator
, workerNode
) =>
419 accumulator
.concat(workerNode
.usage
.waitTime
.history
),
425 ...(this.workerChoiceStrategyContext
.getTaskStatisticsRequirements()
426 .waitTime
.median
&& {
429 this.workerNodes
.reduce
<number[]>(
430 (accumulator
, workerNode
) =>
431 accumulator
.concat(workerNode
.usage
.waitTime
.history
),
443 * The pool readiness boolean status.
445 private get
ready (): boolean {
447 this.workerNodes
.reduce(
448 (accumulator
, workerNode
) =>
449 !workerNode
.info
.dynamic
&& workerNode
.info
.ready
453 ) >= this.minimumNumberOfWorkers
458 * The approximate pool utilization.
460 * @returns The pool utilization.
462 private get
utilization (): number {
463 const poolTimeCapacity
=
464 (performance
.now() - this.startTimestamp
) *
465 (this.maximumNumberOfWorkers
?? this.minimumNumberOfWorkers
)
466 const totalTasksRunTime
= this.workerNodes
.reduce(
467 (accumulator
, workerNode
) =>
468 accumulator
+ (workerNode
.usage
.runTime
.aggregate
?? 0),
471 const totalTasksWaitTime
= this.workerNodes
.reduce(
472 (accumulator
, workerNode
) =>
473 accumulator
+ (workerNode
.usage
.waitTime
.aggregate
?? 0),
476 return (totalTasksRunTime
+ totalTasksWaitTime
) / poolTimeCapacity
482 * If it is `'dynamic'`, it provides the `max` property.
484 protected abstract get
type (): PoolType
489 protected abstract get
worker (): WorkerType
492 * Checks if the worker id sent in the received message from a worker is valid.
494 * @param message - The received message.
495 * @throws {@link https://nodejs.org/api/errors.html#class-error} If the worker id is invalid.
497 private checkMessageWorkerId (message
: MessageValue
<Data
| Response
>): void {
498 if (message
.workerId
== null) {
499 throw new Error('Worker message received without worker id')
500 } else if (this.getWorkerNodeKeyByWorkerId(message
.workerId
) === -1) {
502 `Worker message received from unknown worker '${message.workerId}'`
508 * Gets the worker node key given its worker id.
510 * @param workerId - The worker id.
511 * @returns The worker node key if the worker id is found in the pool worker nodes, `-1` otherwise.
513 private getWorkerNodeKeyByWorkerId (workerId
: number | undefined): number {
514 return this.workerNodes
.findIndex(
515 workerNode
=> workerNode
.info
.id
=== workerId
520 public setWorkerChoiceStrategy (
521 workerChoiceStrategy
: WorkerChoiceStrategy
,
522 workerChoiceStrategyOptions
?: WorkerChoiceStrategyOptions
524 checkValidWorkerChoiceStrategy(workerChoiceStrategy
)
525 this.opts
.workerChoiceStrategy
= workerChoiceStrategy
526 this.workerChoiceStrategyContext
?.setWorkerChoiceStrategy(
527 this.opts
.workerChoiceStrategy
529 if (workerChoiceStrategyOptions
!= null) {
530 this.setWorkerChoiceStrategyOptions(workerChoiceStrategyOptions
)
532 for (const [workerNodeKey
, workerNode
] of this.workerNodes
.entries()) {
533 workerNode
.resetUsage()
534 this.sendStatisticsMessageToWorker(workerNodeKey
)
539 public setWorkerChoiceStrategyOptions (
540 workerChoiceStrategyOptions
: WorkerChoiceStrategyOptions
| undefined
542 this.checkValidWorkerChoiceStrategyOptions(workerChoiceStrategyOptions
)
543 if (workerChoiceStrategyOptions
!= null) {
544 this.opts
.workerChoiceStrategyOptions
= workerChoiceStrategyOptions
546 this.workerChoiceStrategyContext
?.setOptions(
547 this.opts
.workerChoiceStrategyOptions
552 public enableTasksQueue (
554 tasksQueueOptions
?: TasksQueueOptions
556 if (this.opts
.enableTasksQueue
=== true && !enable
) {
557 this.unsetTaskStealing()
558 this.unsetTasksStealingOnBackPressure()
559 this.flushTasksQueues()
561 this.opts
.enableTasksQueue
= enable
562 this.setTasksQueueOptions(tasksQueueOptions
)
566 public setTasksQueueOptions (
567 tasksQueueOptions
: TasksQueueOptions
| undefined
569 if (this.opts
.enableTasksQueue
=== true) {
570 checkValidTasksQueueOptions(tasksQueueOptions
)
571 this.opts
.tasksQueueOptions
=
572 this.buildTasksQueueOptions(tasksQueueOptions
)
573 // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
574 this.setTasksQueueSize(this.opts
.tasksQueueOptions
.size
!)
575 if (this.opts
.tasksQueueOptions
.taskStealing
=== true) {
576 this.unsetTaskStealing()
577 this.setTaskStealing()
579 this.unsetTaskStealing()
581 if (this.opts
.tasksQueueOptions
.tasksStealingOnBackPressure
=== true) {
582 this.unsetTasksStealingOnBackPressure()
583 this.setTasksStealingOnBackPressure()
585 this.unsetTasksStealingOnBackPressure()
587 } else if (this.opts
.tasksQueueOptions
!= null) {
588 delete this.opts
.tasksQueueOptions
592 private buildTasksQueueOptions (
593 tasksQueueOptions
: TasksQueueOptions
| undefined
594 ): TasksQueueOptions
{
596 ...getDefaultTasksQueueOptions(
597 this.maximumNumberOfWorkers
?? this.minimumNumberOfWorkers
603 private setTasksQueueSize (size
: number): void {
604 for (const workerNode
of this.workerNodes
) {
605 workerNode
.tasksQueueBackPressureSize
= size
609 private setTaskStealing (): void {
610 for (const [workerNodeKey
] of this.workerNodes
.entries()) {
611 this.workerNodes
[workerNodeKey
].on('idle', this.handleWorkerNodeIdleEvent
)
615 private unsetTaskStealing (): void {
616 for (const [workerNodeKey
] of this.workerNodes
.entries()) {
617 this.workerNodes
[workerNodeKey
].off(
619 this.handleWorkerNodeIdleEvent
624 private setTasksStealingOnBackPressure (): void {
625 for (const [workerNodeKey
] of this.workerNodes
.entries()) {
626 this.workerNodes
[workerNodeKey
].on(
628 this.handleWorkerNodeBackPressureEvent
633 private unsetTasksStealingOnBackPressure (): void {
634 for (const [workerNodeKey
] of this.workerNodes
.entries()) {
635 this.workerNodes
[workerNodeKey
].off(
637 this.handleWorkerNodeBackPressureEvent
643 * Whether the pool is full or not.
645 * The pool filling boolean status.
647 protected get
full (): boolean {
649 this.workerNodes
.length
>=
650 (this.maximumNumberOfWorkers
?? this.minimumNumberOfWorkers
)
655 * Whether the pool is busy or not.
657 * The pool busyness boolean status.
659 protected abstract get
busy (): boolean
662 * Whether worker nodes are executing concurrently their tasks quota or not.
664 * @returns Worker nodes busyness boolean status.
666 protected internalBusy (): boolean {
667 if (this.opts
.enableTasksQueue
=== true) {
669 this.workerNodes
.findIndex(
671 workerNode
.info
.ready
&&
672 workerNode
.usage
.tasks
.executing
<
673 // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
674 this.opts
.tasksQueueOptions
!.concurrency
!
679 this.workerNodes
.findIndex(
681 workerNode
.info
.ready
&& workerNode
.usage
.tasks
.executing
=== 0
686 private isWorkerNodeBusy (workerNodeKey
: number): boolean {
687 if (this.opts
.enableTasksQueue
=== true) {
689 this.workerNodes
[workerNodeKey
].usage
.tasks
.executing
>=
690 // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
691 this.opts
.tasksQueueOptions
!.concurrency
!
694 return this.workerNodes
[workerNodeKey
].usage
.tasks
.executing
> 0
697 private async sendTaskFunctionOperationToWorker (
698 workerNodeKey
: number,
699 message
: MessageValue
<Data
>
700 ): Promise
<boolean> {
701 return await new Promise
<boolean>((resolve
, reject
) => {
702 const taskFunctionOperationListener
= (
703 message
: MessageValue
<Response
>
705 this.checkMessageWorkerId(message
)
706 const workerId
= this.getWorkerInfo(workerNodeKey
)?.id
708 message
.taskFunctionOperationStatus
!= null &&
709 message
.workerId
=== workerId
711 if (message
.taskFunctionOperationStatus
) {
716 `Task function operation '${message.taskFunctionOperation}' failed on worker ${message.workerId} with error: '${message.workerError?.message}'`
720 this.deregisterWorkerMessageListener(
721 this.getWorkerNodeKeyByWorkerId(message
.workerId
),
722 taskFunctionOperationListener
726 this.registerWorkerMessageListener(
728 taskFunctionOperationListener
730 this.sendToWorker(workerNodeKey
, message
)
734 private async sendTaskFunctionOperationToWorkers (
735 message
: MessageValue
<Data
>
736 ): Promise
<boolean> {
737 return await new Promise
<boolean>((resolve
, reject
) => {
738 const responsesReceived
= new Array<MessageValue
<Response
>>()
739 const taskFunctionOperationsListener
= (
740 message
: MessageValue
<Response
>
742 this.checkMessageWorkerId(message
)
743 if (message
.taskFunctionOperationStatus
!= null) {
744 responsesReceived
.push(message
)
745 if (responsesReceived
.length
=== this.workerNodes
.length
) {
747 responsesReceived
.every(
748 message
=> message
.taskFunctionOperationStatus
=== true
753 responsesReceived
.some(
754 message
=> message
.taskFunctionOperationStatus
=== false
757 const errorResponse
= responsesReceived
.find(
758 response
=> response
.taskFunctionOperationStatus
=== false
762 `Task function operation '${
763 message.taskFunctionOperation as string
764 }' failed on worker ${errorResponse?.workerId} with error: '${
765 errorResponse?.workerError?.message
770 this.deregisterWorkerMessageListener(
771 this.getWorkerNodeKeyByWorkerId(message
.workerId
),
772 taskFunctionOperationsListener
777 for (const [workerNodeKey
] of this.workerNodes
.entries()) {
778 this.registerWorkerMessageListener(
780 taskFunctionOperationsListener
782 this.sendToWorker(workerNodeKey
, message
)
788 public hasTaskFunction (name
: string): boolean {
789 for (const workerNode
of this.workerNodes
) {
791 Array.isArray(workerNode
.info
.taskFunctionNames
) &&
792 workerNode
.info
.taskFunctionNames
.includes(name
)
801 public async addTaskFunction (
803 fn
: TaskFunction
<Data
, Response
>
804 ): Promise
<boolean> {
805 if (typeof name
!== 'string') {
806 throw new TypeError('name argument must be a string')
808 if (typeof name
=== 'string' && name
.trim().length
=== 0) {
809 throw new TypeError('name argument must not be an empty string')
811 if (typeof fn
!== 'function') {
812 throw new TypeError('fn argument must be a function')
814 const opResult
= await this.sendTaskFunctionOperationToWorkers({
815 taskFunctionOperation
: 'add',
816 taskFunctionName
: name
,
817 taskFunction
: fn
.toString()
819 this.taskFunctions
.set(name
, fn
)
824 public async removeTaskFunction (name
: string): Promise
<boolean> {
825 if (!this.taskFunctions
.has(name
)) {
827 'Cannot remove a task function not handled on the pool side'
830 const opResult
= await this.sendTaskFunctionOperationToWorkers({
831 taskFunctionOperation
: 'remove',
832 taskFunctionName
: name
834 this.deleteTaskFunctionWorkerUsages(name
)
835 this.taskFunctions
.delete(name
)
840 public listTaskFunctionNames (): string[] {
841 for (const workerNode
of this.workerNodes
) {
843 Array.isArray(workerNode
.info
.taskFunctionNames
) &&
844 workerNode
.info
.taskFunctionNames
.length
> 0
846 return workerNode
.info
.taskFunctionNames
853 public async setDefaultTaskFunction (name
: string): Promise
<boolean> {
854 return await this.sendTaskFunctionOperationToWorkers({
855 taskFunctionOperation
: 'default',
856 taskFunctionName
: name
860 private deleteTaskFunctionWorkerUsages (name
: string): void {
861 for (const workerNode
of this.workerNodes
) {
862 workerNode
.deleteTaskFunctionWorkerUsage(name
)
866 private shallExecuteTask (workerNodeKey
: number): boolean {
868 this.tasksQueueSize(workerNodeKey
) === 0 &&
869 this.workerNodes
[workerNodeKey
].usage
.tasks
.executing
<
870 // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
871 this.opts
.tasksQueueOptions
!.concurrency
!
876 public async execute (
879 transferList
?: TransferListItem
[]
880 ): Promise
<Response
> {
881 return await new Promise
<Response
>((resolve
, reject
) => {
883 reject(new Error('Cannot execute a task on not started pool'))
886 if (this.destroying
) {
887 reject(new Error('Cannot execute a task on destroying pool'))
890 if (name
!= null && typeof name
!== 'string') {
891 reject(new TypeError('name argument must be a string'))
896 typeof name
=== 'string' &&
897 name
.trim().length
=== 0
899 reject(new TypeError('name argument must not be an empty string'))
902 if (transferList
!= null && !Array.isArray(transferList
)) {
903 reject(new TypeError('transferList argument must be an array'))
906 const timestamp
= performance
.now()
907 const workerNodeKey
= this.chooseWorkerNode()
908 const task
: Task
<Data
> = {
909 name
: name
?? DEFAULT_TASK_NAME
,
910 // eslint-disable-next-line @typescript-eslint/consistent-type-assertions
911 data
: data
?? ({} as Data
),
916 // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
917 this.promiseResponseMap
.set(task
.taskId
!, {
921 ...(this.emitter
!= null && {
922 asyncResource
: new AsyncResource('poolifier:task', {
923 triggerAsyncId
: this.emitter
.asyncId
,
924 requireManualDestroy
: true
929 this.opts
.enableTasksQueue
=== false ||
930 (this.opts
.enableTasksQueue
=== true &&
931 this.shallExecuteTask(workerNodeKey
))
933 this.executeTask(workerNodeKey
, task
)
935 this.enqueueTask(workerNodeKey
, task
)
941 public start (): void {
943 throw new Error('Cannot start an already started pool')
946 throw new Error('Cannot start an already starting pool')
948 if (this.destroying
) {
949 throw new Error('Cannot start a destroying pool')
953 this.workerNodes
.reduce(
954 (accumulator
, workerNode
) =>
955 !workerNode
.info
.dynamic
? accumulator
+ 1 : accumulator
,
957 ) < this.minimumNumberOfWorkers
959 this.createAndSetupWorkerNode()
961 this.starting
= false
966 public async destroy (): Promise
<void> {
968 throw new Error('Cannot destroy an already destroyed pool')
971 throw new Error('Cannot destroy an starting pool')
973 if (this.destroying
) {
974 throw new Error('Cannot destroy an already destroying pool')
976 this.destroying
= true
978 this.workerNodes
.map(async (_workerNode
, workerNodeKey
) => {
979 await this.destroyWorkerNode(workerNodeKey
)
982 this.emitter
?.emit(PoolEvents
.destroy
, this.info
)
983 this.emitter
?.emitDestroy()
984 this.emitter
?.removeAllListeners()
985 this.readyEventEmitted
= false
986 this.destroying
= false
990 private async sendKillMessageToWorker (workerNodeKey
: number): Promise
<void> {
991 await new Promise
<void>((resolve
, reject
) => {
992 // eslint-disable-next-line @typescript-eslint/no-unnecessary-condition
993 if (this.workerNodes
[workerNodeKey
] == null) {
997 const killMessageListener
= (message
: MessageValue
<Response
>): void => {
998 this.checkMessageWorkerId(message
)
999 if (message
.kill
=== 'success') {
1001 } else if (message
.kill
=== 'failure') {
1004 `Kill message handling failed on worker ${message.workerId}`
1009 // FIXME: should be registered only once
1010 this.registerWorkerMessageListener(workerNodeKey
, killMessageListener
)
1011 this.sendToWorker(workerNodeKey
, { kill
: true })
1016 * Terminates the worker node given its worker node key.
1018 * @param workerNodeKey - The worker node key.
1020 protected async destroyWorkerNode (workerNodeKey
: number): Promise
<void> {
1021 this.flagWorkerNodeAsNotReady(workerNodeKey
)
1022 const flushedTasks
= this.flushTasksQueue(workerNodeKey
)
1023 const workerNode
= this.workerNodes
[workerNodeKey
]
1024 await waitWorkerNodeEvents(
1028 this.opts
.tasksQueueOptions
?.tasksFinishedTimeout
??
1029 getDefaultTasksQueueOptions(
1030 this.maximumNumberOfWorkers
?? this.minimumNumberOfWorkers
1031 ).tasksFinishedTimeout
1033 await this.sendKillMessageToWorker(workerNodeKey
)
1034 await workerNode
.terminate()
1038 * Setup hook to execute code before worker nodes are created in the abstract constructor.
1039 * Can be overridden.
1043 protected setupHook (): void {
1044 /* Intentionally empty */
1048 * Should return whether the worker is the main worker or not.
1050 protected abstract isMain (): boolean
1053 * Hook executed before the worker task execution.
1054 * Can be overridden.
1056 * @param workerNodeKey - The worker node key.
1057 * @param task - The task to execute.
1059 protected beforeTaskExecutionHook (
1060 workerNodeKey
: number,
1063 // eslint-disable-next-line @typescript-eslint/no-unnecessary-condition
1064 if (this.workerNodes
[workerNodeKey
]?.usage
!= null) {
1065 const workerUsage
= this.workerNodes
[workerNodeKey
].usage
1066 ++workerUsage
.tasks
.executing
1067 updateWaitTimeWorkerUsage(
1068 this.workerChoiceStrategyContext
,
1074 this.shallUpdateTaskFunctionWorkerUsage(workerNodeKey
) &&
1075 // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
1076 this.workerNodes
[workerNodeKey
].getTaskFunctionWorkerUsage(task
.name
!) !=
1079 // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
1080 const taskFunctionWorkerUsage
= this.workerNodes
[
1082 // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
1083 ].getTaskFunctionWorkerUsage(task
.name
!)!
1084 ++taskFunctionWorkerUsage
.tasks
.executing
1085 updateWaitTimeWorkerUsage(
1086 this.workerChoiceStrategyContext
,
1087 taskFunctionWorkerUsage
,
1094 * Hook executed after the worker task execution.
1095 * Can be overridden.
1097 * @param workerNodeKey - The worker node key.
1098 * @param message - The received message.
1100 protected afterTaskExecutionHook (
1101 workerNodeKey
: number,
1102 message
: MessageValue
<Response
>
1104 let needWorkerChoiceStrategyUpdate
= false
1105 // eslint-disable-next-line @typescript-eslint/no-unnecessary-condition
1106 if (this.workerNodes
[workerNodeKey
]?.usage
!= null) {
1107 const workerUsage
= this.workerNodes
[workerNodeKey
].usage
1108 updateTaskStatisticsWorkerUsage(workerUsage
, message
)
1109 updateRunTimeWorkerUsage(
1110 this.workerChoiceStrategyContext
,
1114 updateEluWorkerUsage(
1115 this.workerChoiceStrategyContext
,
1119 needWorkerChoiceStrategyUpdate
= true
1122 this.shallUpdateTaskFunctionWorkerUsage(workerNodeKey
) &&
1123 this.workerNodes
[workerNodeKey
].getTaskFunctionWorkerUsage(
1124 // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
1125 message
.taskPerformance
!.name
1128 // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
1129 const taskFunctionWorkerUsage
= this.workerNodes
[
1131 // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
1132 ].getTaskFunctionWorkerUsage(message
.taskPerformance
!.name
)!
1133 updateTaskStatisticsWorkerUsage(taskFunctionWorkerUsage
, message
)
1134 updateRunTimeWorkerUsage(
1135 this.workerChoiceStrategyContext
,
1136 taskFunctionWorkerUsage
,
1139 updateEluWorkerUsage(
1140 this.workerChoiceStrategyContext
,
1141 taskFunctionWorkerUsage
,
1144 needWorkerChoiceStrategyUpdate
= true
1146 if (needWorkerChoiceStrategyUpdate
) {
1147 this.workerChoiceStrategyContext
?.update(workerNodeKey
)
1152 * Whether the worker node shall update its task function worker usage or not.
1154 * @param workerNodeKey - The worker node key.
1155 * @returns `true` if the worker node shall update its task function worker usage, `false` otherwise.
1157 private shallUpdateTaskFunctionWorkerUsage (workerNodeKey
: number): boolean {
1158 const workerInfo
= this.getWorkerInfo(workerNodeKey
)
1160 workerInfo
!= null &&
1161 Array.isArray(workerInfo
.taskFunctionNames
) &&
1162 workerInfo
.taskFunctionNames
.length
> 2
1167 * Chooses a worker node for the next task.
1169 * The default worker choice strategy uses a round robin algorithm to distribute the tasks.
1171 * @returns The chosen worker node key
1173 private chooseWorkerNode (): number {
1174 if (this.shallCreateDynamicWorker()) {
1175 const workerNodeKey
= this.createAndSetupDynamicWorkerNode()
1177 this.workerChoiceStrategyContext
?.getStrategyPolicy()
1178 .dynamicWorkerUsage
=== true
1180 return workerNodeKey
1183 // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
1184 return this.workerChoiceStrategyContext
!.execute()
1188 * Conditions for dynamic worker creation.
1190 * @returns Whether to create a dynamic worker or not.
1192 protected abstract shallCreateDynamicWorker (): boolean
1195 * Sends a message to worker given its worker node key.
1197 * @param workerNodeKey - The worker node key.
1198 * @param message - The message.
1199 * @param transferList - The optional array of transferable objects.
1201 protected abstract sendToWorker (
1202 workerNodeKey
: number,
1203 message
: MessageValue
<Data
>,
1204 transferList
?: TransferListItem
[]
1208 * Creates a new, completely set up worker node.
1210 * @returns New, completely set up worker node key.
1212 protected createAndSetupWorkerNode (): number {
1213 const workerNode
= this.createWorkerNode()
1214 workerNode
.registerWorkerEventHandler(
1216 this.opts
.onlineHandler
?? EMPTY_FUNCTION
1218 workerNode
.registerWorkerEventHandler(
1220 this.opts
.messageHandler
?? EMPTY_FUNCTION
1222 workerNode
.registerWorkerEventHandler(
1224 this.opts
.errorHandler
?? EMPTY_FUNCTION
1226 workerNode
.registerWorkerEventHandler('error', (error
: Error) => {
1227 workerNode
.info
.ready
= false
1228 this.emitter
?.emit(PoolEvents
.error
, error
)
1232 this.opts
.restartWorkerOnError
=== true
1234 if (workerNode
.info
.dynamic
) {
1235 this.createAndSetupDynamicWorkerNode()
1237 this.createAndSetupWorkerNode()
1243 this.opts
.enableTasksQueue
=== true
1245 this.redistributeQueuedTasks(this.workerNodes
.indexOf(workerNode
))
1247 workerNode
.terminate().catch(error
=> {
1248 this.emitter
?.emit(PoolEvents
.error
, error
)
1251 workerNode
.registerWorkerEventHandler(
1253 this.opts
.exitHandler
?? EMPTY_FUNCTION
1255 workerNode
.registerOnceWorkerEventHandler('exit', () => {
1256 this.removeWorkerNode(workerNode
)
1258 const workerNodeKey
= this.addWorkerNode(workerNode
)
1259 this.afterWorkerNodeSetup(workerNodeKey
)
1260 return workerNodeKey
1264 * Creates a new, completely set up dynamic worker node.
1266 * @returns New, completely set up dynamic worker node key.
1268 protected createAndSetupDynamicWorkerNode (): number {
1269 const workerNodeKey
= this.createAndSetupWorkerNode()
1270 this.registerWorkerMessageListener(workerNodeKey
, message
=> {
1271 this.checkMessageWorkerId(message
)
1272 const localWorkerNodeKey
= this.getWorkerNodeKeyByWorkerId(
1275 const workerUsage
= this.workerNodes
[localWorkerNodeKey
].usage
1276 // Kill message received from worker
1278 isKillBehavior(KillBehaviors
.HARD
, message
.kill
) ||
1279 (isKillBehavior(KillBehaviors
.SOFT
, message
.kill
) &&
1280 ((this.opts
.enableTasksQueue
=== false &&
1281 workerUsage
.tasks
.executing
=== 0) ||
1282 (this.opts
.enableTasksQueue
=== true &&
1283 workerUsage
.tasks
.executing
=== 0 &&
1284 this.tasksQueueSize(localWorkerNodeKey
) === 0)))
1286 // Flag the worker node as not ready immediately
1287 this.flagWorkerNodeAsNotReady(localWorkerNodeKey
)
1288 this.destroyWorkerNode(localWorkerNodeKey
).catch(error
=> {
1289 this.emitter
?.emit(PoolEvents
.error
, error
)
1293 this.sendToWorker(workerNodeKey
, {
1296 if (this.taskFunctions
.size
> 0) {
1297 for (const [taskFunctionName
, taskFunction
] of this.taskFunctions
) {
1298 this.sendTaskFunctionOperationToWorker(workerNodeKey
, {
1299 taskFunctionOperation
: 'add',
1301 taskFunction
: taskFunction
.toString()
1303 this.emitter
?.emit(PoolEvents
.error
, error
)
1307 const workerNode
= this.workerNodes
[workerNodeKey
]
1308 workerNode
.info
.dynamic
= true
1310 this.workerChoiceStrategyContext
?.getStrategyPolicy()
1311 .dynamicWorkerReady
=== true ||
1312 this.workerChoiceStrategyContext
?.getStrategyPolicy()
1313 .dynamicWorkerUsage
=== true
1315 workerNode
.info
.ready
= true
1317 this.checkAndEmitDynamicWorkerCreationEvents()
1318 return workerNodeKey
1322 * Registers a listener callback on the worker given its worker node key.
1324 * @param workerNodeKey - The worker node key.
1325 * @param listener - The message listener callback.
1327 protected abstract registerWorkerMessageListener
<
1328 Message
extends Data
| Response
1330 workerNodeKey
: number,
1331 listener
: (message
: MessageValue
<Message
>) => void
1335 * Registers once a listener callback on the worker given its worker node key.
1337 * @param workerNodeKey - The worker node key.
1338 * @param listener - The message listener callback.
1340 protected abstract registerOnceWorkerMessageListener
<
1341 Message
extends Data
| Response
1343 workerNodeKey
: number,
1344 listener
: (message
: MessageValue
<Message
>) => void
1348 * Deregisters a listener callback on the worker given its worker node key.
1350 * @param workerNodeKey - The worker node key.
1351 * @param listener - The message listener callback.
1353 protected abstract deregisterWorkerMessageListener
<
1354 Message
extends Data
| Response
1356 workerNodeKey
: number,
1357 listener
: (message
: MessageValue
<Message
>) => void
1361 * Method hooked up after a worker node has been newly created.
1362 * Can be overridden.
1364 * @param workerNodeKey - The newly created worker node key.
1366 protected afterWorkerNodeSetup (workerNodeKey
: number): void {
1367 // Listen to worker messages.
1368 this.registerWorkerMessageListener(
1370 this.workerMessageListener
1372 // Send the startup message to worker.
1373 this.sendStartupMessageToWorker(workerNodeKey
)
1374 // Send the statistics message to worker.
1375 this.sendStatisticsMessageToWorker(workerNodeKey
)
1376 if (this.opts
.enableTasksQueue
=== true) {
1377 if (this.opts
.tasksQueueOptions
?.taskStealing
=== true) {
1378 this.workerNodes
[workerNodeKey
].on(
1380 this.handleWorkerNodeIdleEvent
1383 if (this.opts
.tasksQueueOptions
?.tasksStealingOnBackPressure
=== true) {
1384 this.workerNodes
[workerNodeKey
].on(
1386 this.handleWorkerNodeBackPressureEvent
1393 * Sends the startup message to worker given its worker node key.
1395 * @param workerNodeKey - The worker node key.
1397 protected abstract sendStartupMessageToWorker (workerNodeKey
: number): void
1400 * Sends the statistics message to worker given its worker node key.
1402 * @param workerNodeKey - The worker node key.
1404 private sendStatisticsMessageToWorker (workerNodeKey
: number): void {
1405 this.sendToWorker(workerNodeKey
, {
1408 this.workerChoiceStrategyContext
?.getTaskStatisticsRequirements()
1409 ?.runTime
.aggregate
?? false,
1411 this.workerChoiceStrategyContext
?.getTaskStatisticsRequirements()?.elu
1417 private cannotStealTask (): boolean {
1418 return this.workerNodes
.length
<= 1 || this.info
.queuedTasks
=== 0
1421 private handleTask (workerNodeKey
: number, task
: Task
<Data
>): void {
1422 if (this.shallExecuteTask(workerNodeKey
)) {
1423 this.executeTask(workerNodeKey
, task
)
1425 this.enqueueTask(workerNodeKey
, task
)
1429 private redistributeQueuedTasks (workerNodeKey
: number): void {
1430 if (workerNodeKey
=== -1 || this.cannotStealTask()) {
1433 while (this.tasksQueueSize(workerNodeKey
) > 0) {
1434 const destinationWorkerNodeKey
= this.workerNodes
.reduce(
1435 (minWorkerNodeKey
, workerNode
, workerNodeKey
, workerNodes
) => {
1436 return workerNode
.info
.ready
&&
1437 workerNode
.usage
.tasks
.queued
<
1438 workerNodes
[minWorkerNodeKey
].usage
.tasks
.queued
1445 destinationWorkerNodeKey
,
1446 // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
1447 this.dequeueTask(workerNodeKey
)!
1452 private updateTaskStolenStatisticsWorkerUsage (
1453 workerNodeKey
: number,
1456 const workerNode
= this.workerNodes
[workerNodeKey
]
1457 // eslint-disable-next-line @typescript-eslint/no-unnecessary-condition
1458 if (workerNode
?.usage
!= null) {
1459 ++workerNode
.usage
.tasks
.stolen
1462 this.shallUpdateTaskFunctionWorkerUsage(workerNodeKey
) &&
1463 workerNode
.getTaskFunctionWorkerUsage(taskName
) != null
1465 const taskFunctionWorkerUsage
=
1466 // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
1467 workerNode
.getTaskFunctionWorkerUsage(taskName
)!
1468 ++taskFunctionWorkerUsage
.tasks
.stolen
1472 private updateTaskSequentiallyStolenStatisticsWorkerUsage (
1473 workerNodeKey
: number
1475 const workerNode
= this.workerNodes
[workerNodeKey
]
1476 // eslint-disable-next-line @typescript-eslint/no-unnecessary-condition
1477 if (workerNode
?.usage
!= null) {
1478 ++workerNode
.usage
.tasks
.sequentiallyStolen
1482 private updateTaskSequentiallyStolenStatisticsTaskFunctionWorkerUsage (
1483 workerNodeKey
: number,
1486 const workerNode
= this.workerNodes
[workerNodeKey
]
1488 this.shallUpdateTaskFunctionWorkerUsage(workerNodeKey
) &&
1489 workerNode
.getTaskFunctionWorkerUsage(taskName
) != null
1491 const taskFunctionWorkerUsage
=
1492 // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
1493 workerNode
.getTaskFunctionWorkerUsage(taskName
)!
1494 ++taskFunctionWorkerUsage
.tasks
.sequentiallyStolen
1498 private resetTaskSequentiallyStolenStatisticsWorkerUsage (
1499 workerNodeKey
: number
1501 const workerNode
= this.workerNodes
[workerNodeKey
]
1502 // eslint-disable-next-line @typescript-eslint/no-unnecessary-condition
1503 if (workerNode
?.usage
!= null) {
1504 workerNode
.usage
.tasks
.sequentiallyStolen
= 0
1508 private resetTaskSequentiallyStolenStatisticsTaskFunctionWorkerUsage (
1509 workerNodeKey
: number,
1512 const workerNode
= this.workerNodes
[workerNodeKey
]
1514 this.shallUpdateTaskFunctionWorkerUsage(workerNodeKey
) &&
1515 workerNode
.getTaskFunctionWorkerUsage(taskName
) != null
1517 const taskFunctionWorkerUsage
=
1518 // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
1519 workerNode
.getTaskFunctionWorkerUsage(taskName
)!
1520 taskFunctionWorkerUsage
.tasks
.sequentiallyStolen
= 0
1524 private readonly handleWorkerNodeIdleEvent
= (
1525 eventDetail
: WorkerNodeEventDetail
,
1526 previousStolenTask
?: Task
<Data
>
1528 const { workerNodeKey
} = eventDetail
1529 if (workerNodeKey
== null) {
1531 "WorkerNode event detail 'workerNodeKey' property must be defined"
1534 const workerInfo
= this.getWorkerInfo(workerNodeKey
)
1536 this.cannotStealTask() ||
1537 (this.info
.stealingWorkerNodes
?? 0) >
1538 Math.floor(this.workerNodes
.length
/ 2)
1540 if (workerInfo
!= null && previousStolenTask
!= null) {
1541 workerInfo
.stealing
= false
1545 const workerNodeTasksUsage
= this.workerNodes
[workerNodeKey
].usage
.tasks
1547 workerInfo
!= null &&
1548 previousStolenTask
!= null &&
1549 workerNodeTasksUsage
.sequentiallyStolen
> 0 &&
1550 (workerNodeTasksUsage
.executing
> 0 ||
1551 this.tasksQueueSize(workerNodeKey
) > 0)
1553 workerInfo
.stealing
= false
1554 // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
1555 for (const taskName
of this.workerNodes
[workerNodeKey
].info
1556 .taskFunctionNames
!) {
1557 this.resetTaskSequentiallyStolenStatisticsTaskFunctionWorkerUsage(
1562 this.resetTaskSequentiallyStolenStatisticsWorkerUsage(workerNodeKey
)
1565 if (workerInfo
== null) {
1567 `Worker node with key '${workerNodeKey}' not found in pool`
1570 workerInfo
.stealing
= true
1571 const stolenTask
= this.workerNodeStealTask(workerNodeKey
)
1573 this.shallUpdateTaskFunctionWorkerUsage(workerNodeKey
) &&
1576 // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
1577 const taskFunctionTasksWorkerUsage
= this.workerNodes
[
1579 // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
1580 ].getTaskFunctionWorkerUsage(stolenTask
.name
!)!.tasks
1582 taskFunctionTasksWorkerUsage
.sequentiallyStolen
=== 0 ||
1583 (previousStolenTask
!= null &&
1584 previousStolenTask
.name
=== stolenTask
.name
&&
1585 taskFunctionTasksWorkerUsage
.sequentiallyStolen
> 0)
1587 this.updateTaskSequentiallyStolenStatisticsTaskFunctionWorkerUsage(
1589 // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
1593 this.resetTaskSequentiallyStolenStatisticsTaskFunctionWorkerUsage(
1595 // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
1600 sleep(exponentialDelay(workerNodeTasksUsage
.sequentiallyStolen
))
1602 this.handleWorkerNodeIdleEvent(eventDetail
, stolenTask
)
1605 .catch(EMPTY_FUNCTION
)
1608 private readonly workerNodeStealTask
= (
1609 workerNodeKey
: number
1610 ): Task
<Data
> | undefined => {
1611 const workerNodes
= this.workerNodes
1614 (workerNodeA
, workerNodeB
) =>
1615 workerNodeB
.usage
.tasks
.queued
- workerNodeA
.usage
.tasks
.queued
1617 const sourceWorkerNode
= workerNodes
.find(
1618 (sourceWorkerNode
, sourceWorkerNodeKey
) =>
1619 sourceWorkerNode
.info
.ready
&&
1620 !sourceWorkerNode
.info
.stealing
&&
1621 sourceWorkerNodeKey
!== workerNodeKey
&&
1622 sourceWorkerNode
.usage
.tasks
.queued
> 0
1624 if (sourceWorkerNode
!= null) {
1625 // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
1626 const task
= sourceWorkerNode
.popTask()!
1627 this.handleTask(workerNodeKey
, task
)
1628 this.updateTaskSequentiallyStolenStatisticsWorkerUsage(workerNodeKey
)
1629 // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
1630 this.updateTaskStolenStatisticsWorkerUsage(workerNodeKey
, task
.name
!)
1635 private readonly handleWorkerNodeBackPressureEvent
= (
1636 eventDetail
: WorkerNodeEventDetail
1639 this.cannotStealTask() ||
1640 (this.info
.stealingWorkerNodes
?? 0) >
1641 Math.floor(this.workerNodes
.length
/ 2)
1645 const { workerId
} = eventDetail
1646 const sizeOffset
= 1
1647 // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
1648 if (this.opts
.tasksQueueOptions
!.size
! <= sizeOffset
) {
1651 const sourceWorkerNode
=
1652 this.workerNodes
[this.getWorkerNodeKeyByWorkerId(workerId
)]
1653 const workerNodes
= this.workerNodes
1656 (workerNodeA
, workerNodeB
) =>
1657 workerNodeA
.usage
.tasks
.queued
- workerNodeB
.usage
.tasks
.queued
1659 for (const [workerNodeKey
, workerNode
] of workerNodes
.entries()) {
1661 sourceWorkerNode
.usage
.tasks
.queued
> 0 &&
1662 workerNode
.info
.ready
&&
1663 !workerNode
.info
.stealing
&&
1664 workerNode
.info
.id
!== workerId
&&
1665 workerNode
.usage
.tasks
.queued
<
1666 // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
1667 this.opts
.tasksQueueOptions
!.size
! - sizeOffset
1669 const workerInfo
= this.getWorkerInfo(workerNodeKey
)
1670 if (workerInfo
== null) {
1672 `Worker node with key '${workerNodeKey}' not found in pool`
1675 workerInfo
.stealing
= true
1676 // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
1677 const task
= sourceWorkerNode
.popTask()!
1678 this.handleTask(workerNodeKey
, task
)
1679 // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
1680 this.updateTaskStolenStatisticsWorkerUsage(workerNodeKey
, task
.name
!)
1681 workerInfo
.stealing
= false
1687 * This method is the message listener registered on each worker.
1689 protected readonly workerMessageListener
= (
1690 message
: MessageValue
<Response
>
1692 this.checkMessageWorkerId(message
)
1693 const { workerId
, ready
, taskId
, taskFunctionNames
} = message
1694 if (ready
!= null && taskFunctionNames
!= null) {
1695 // Worker ready response received from worker
1696 this.handleWorkerReadyResponse(message
)
1697 } else if (taskId
!= null) {
1698 // Task execution response received from worker
1699 this.handleTaskExecutionResponse(message
)
1700 } else if (taskFunctionNames
!= null) {
1701 // Task function names message received from worker
1702 const workerInfo
= this.getWorkerInfo(
1703 this.getWorkerNodeKeyByWorkerId(workerId
)
1705 if (workerInfo
!= null) {
1706 workerInfo
.taskFunctionNames
= taskFunctionNames
1711 private handleWorkerReadyResponse (message
: MessageValue
<Response
>): void {
1712 const { workerId
, ready
, taskFunctionNames
} = message
1713 if (ready
== null || !ready
) {
1714 throw new Error(`Worker ${workerId} failed to initialize`)
1717 this.workerNodes
[this.getWorkerNodeKeyByWorkerId(workerId
)]
1718 workerNode
.info
.ready
= ready
1719 workerNode
.info
.taskFunctionNames
= taskFunctionNames
1720 if (!this.readyEventEmitted
&& this.ready
) {
1721 this.emitter
?.emit(PoolEvents
.ready
, this.info
)
1722 this.readyEventEmitted
= true
1726 private handleTaskExecutionResponse (message
: MessageValue
<Response
>): void {
1727 const { workerId
, taskId
, workerError
, data
} = message
1728 // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
1729 const promiseResponse
= this.promiseResponseMap
.get(taskId
!)
1730 if (promiseResponse
!= null) {
1731 const { resolve
, reject
, workerNodeKey
, asyncResource
} = promiseResponse
1732 const workerNode
= this.workerNodes
[workerNodeKey
]
1733 if (workerError
!= null) {
1734 this.emitter
?.emit(PoolEvents
.taskError
, workerError
)
1735 asyncResource
!= null
1736 ? asyncResource
.runInAsyncScope(
1741 : reject(workerError
.message
)
1743 asyncResource
!= null
1744 ? asyncResource
.runInAsyncScope(resolve
, this.emitter
, data
)
1745 : resolve(data
as Response
)
1747 asyncResource
?.emitDestroy()
1748 this.afterTaskExecutionHook(workerNodeKey
, message
)
1749 // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
1750 this.promiseResponseMap
.delete(taskId
!)
1751 // eslint-disable-next-line @typescript-eslint/no-unnecessary-condition
1752 workerNode
?.emit('taskFinished', taskId
)
1753 if (this.opts
.enableTasksQueue
=== true && !this.destroying
) {
1754 const workerNodeTasksUsage
= workerNode
.usage
.tasks
1756 this.tasksQueueSize(workerNodeKey
) > 0 &&
1757 workerNodeTasksUsage
.executing
<
1758 // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
1759 this.opts
.tasksQueueOptions
!.concurrency
!
1761 // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
1762 this.executeTask(workerNodeKey
, this.dequeueTask(workerNodeKey
)!)
1765 workerNodeTasksUsage
.executing
=== 0 &&
1766 this.tasksQueueSize(workerNodeKey
) === 0 &&
1767 workerNodeTasksUsage
.sequentiallyStolen
=== 0
1769 workerNode
.emit('idle', {
1770 // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
1771 workerId
: workerId
!,
1779 private checkAndEmitTaskExecutionEvents (): void {
1781 this.emitter
?.emit(PoolEvents
.busy
, this.info
)
1785 private checkAndEmitTaskQueuingEvents (): void {
1786 if (this.hasBackPressure()) {
1787 this.emitter
?.emit(PoolEvents
.backPressure
, this.info
)
1792 * Emits dynamic worker creation events.
1794 protected abstract checkAndEmitDynamicWorkerCreationEvents (): void
1797 * Gets the worker information given its worker node key.
1799 * @param workerNodeKey - The worker node key.
1800 * @returns The worker information.
1802 protected getWorkerInfo (workerNodeKey
: number): WorkerInfo
| undefined {
1803 return this.workerNodes
[workerNodeKey
]?.info
1807 * Creates a worker node.
1809 * @returns The created worker node.
1811 private createWorkerNode (): IWorkerNode
<Worker
, Data
> {
1812 const workerNode
= new WorkerNode
<Worker
, Data
>(
1817 workerOptions
: this.opts
.workerOptions
,
1818 tasksQueueBackPressureSize
:
1819 this.opts
.tasksQueueOptions
?.size
??
1820 getDefaultTasksQueueOptions(
1821 this.maximumNumberOfWorkers
?? this.minimumNumberOfWorkers
1825 // Flag the worker node as ready at pool startup.
1826 if (this.starting
) {
1827 workerNode
.info
.ready
= true
1833 * Adds the given worker node in the pool worker nodes.
1835 * @param workerNode - The worker node.
1836 * @returns The added worker node key.
1837 * @throws {@link https://nodejs.org/api/errors.html#class-error} If the added worker node is not found.
1839 private addWorkerNode (workerNode
: IWorkerNode
<Worker
, Data
>): number {
1840 this.workerNodes
.push(workerNode
)
1841 const workerNodeKey
= this.workerNodes
.indexOf(workerNode
)
1842 if (workerNodeKey
=== -1) {
1843 throw new Error('Worker added not found in worker nodes')
1845 return workerNodeKey
1849 * Removes the worker node from the pool worker nodes.
1851 * @param workerNode - The worker node.
1853 private removeWorkerNode (workerNode
: IWorkerNode
<Worker
, Data
>): void {
1854 const workerNodeKey
= this.workerNodes
.indexOf(workerNode
)
1855 if (workerNodeKey
!== -1) {
1856 this.workerNodes
.splice(workerNodeKey
, 1)
1857 this.workerChoiceStrategyContext
?.remove(workerNodeKey
)
1861 protected flagWorkerNodeAsNotReady (workerNodeKey
: number): void {
1862 const workerInfo
= this.getWorkerInfo(workerNodeKey
)
1863 if (workerInfo
!= null) {
1864 workerInfo
.ready
= false
1868 private hasBackPressure (): boolean {
1870 this.opts
.enableTasksQueue
=== true &&
1871 this.workerNodes
.findIndex(
1872 workerNode
=> !workerNode
.hasBackPressure()
1878 * Executes the given task on the worker given its worker node key.
1880 * @param workerNodeKey - The worker node key.
1881 * @param task - The task to execute.
1883 private executeTask (workerNodeKey
: number, task
: Task
<Data
>): void {
1884 this.beforeTaskExecutionHook(workerNodeKey
, task
)
1885 this.sendToWorker(workerNodeKey
, task
, task
.transferList
)
1886 this.checkAndEmitTaskExecutionEvents()
1889 private enqueueTask (workerNodeKey
: number, task
: Task
<Data
>): number {
1890 const tasksQueueSize
= this.workerNodes
[workerNodeKey
].enqueueTask(task
)
1891 this.checkAndEmitTaskQueuingEvents()
1892 return tasksQueueSize
1895 private dequeueTask (workerNodeKey
: number): Task
<Data
> | undefined {
1896 return this.workerNodes
[workerNodeKey
].dequeueTask()
1899 private tasksQueueSize (workerNodeKey
: number): number {
1900 return this.workerNodes
[workerNodeKey
].tasksQueueSize()
1903 protected flushTasksQueue (workerNodeKey
: number): number {
1904 let flushedTasks
= 0
1905 while (this.tasksQueueSize(workerNodeKey
) > 0) {
1906 // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
1907 this.executeTask(workerNodeKey
, this.dequeueTask(workerNodeKey
)!)
1910 this.workerNodes
[workerNodeKey
].clearTasksQueue()
1914 private flushTasksQueues (): void {
1915 for (const [workerNodeKey
] of this.workerNodes
.entries()) {
1916 this.flushTasksQueue(workerNodeKey
)