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 {
450 this.workerNodes
.reduce(
451 (accumulator
, workerNode
) =>
452 !workerNode
.info
.dynamic
&& workerNode
.info
.ready
456 ) >= this.minimumNumberOfWorkers
461 * The pool emptiness boolean status.
463 protected get
empty (): boolean {
464 if (this.minimumNumberOfWorkers
=== 0 && this.workerNodes
.length
=== 0) {
471 * The approximate pool utilization.
473 * @returns The pool utilization.
475 private get
utilization (): number {
476 const poolTimeCapacity
=
477 (performance
.now() - this.startTimestamp
) *
478 (this.maximumNumberOfWorkers
?? this.minimumNumberOfWorkers
)
479 const totalTasksRunTime
= this.workerNodes
.reduce(
480 (accumulator
, workerNode
) =>
481 accumulator
+ (workerNode
.usage
.runTime
.aggregate
?? 0),
484 const totalTasksWaitTime
= this.workerNodes
.reduce(
485 (accumulator
, workerNode
) =>
486 accumulator
+ (workerNode
.usage
.waitTime
.aggregate
?? 0),
489 return (totalTasksRunTime
+ totalTasksWaitTime
) / poolTimeCapacity
495 * If it is `'dynamic'`, it provides the `max` property.
497 protected abstract get
type (): PoolType
502 protected abstract get
worker (): WorkerType
505 * Checks if the worker id sent in the received message from a worker is valid.
507 * @param message - The received message.
508 * @throws {@link https://nodejs.org/api/errors.html#class-error} If the worker id is invalid.
510 private checkMessageWorkerId (message
: MessageValue
<Data
| Response
>): void {
511 if (message
.workerId
== null) {
512 throw new Error('Worker message received without worker id')
513 } else if (this.getWorkerNodeKeyByWorkerId(message
.workerId
) === -1) {
515 `Worker message received from unknown worker '${message.workerId}'`
521 * Gets the worker node key given its worker id.
523 * @param workerId - The worker id.
524 * @returns The worker node key if the worker id is found in the pool worker nodes, `-1` otherwise.
526 private getWorkerNodeKeyByWorkerId (workerId
: number | undefined): number {
527 return this.workerNodes
.findIndex(
528 workerNode
=> workerNode
.info
.id
=== workerId
533 public setWorkerChoiceStrategy (
534 workerChoiceStrategy
: WorkerChoiceStrategy
,
535 workerChoiceStrategyOptions
?: WorkerChoiceStrategyOptions
537 checkValidWorkerChoiceStrategy(workerChoiceStrategy
)
538 this.opts
.workerChoiceStrategy
= workerChoiceStrategy
539 this.workerChoiceStrategyContext
?.setWorkerChoiceStrategy(
540 this.opts
.workerChoiceStrategy
542 if (workerChoiceStrategyOptions
!= null) {
543 this.setWorkerChoiceStrategyOptions(workerChoiceStrategyOptions
)
545 for (const [workerNodeKey
, workerNode
] of this.workerNodes
.entries()) {
546 workerNode
.resetUsage()
547 this.sendStatisticsMessageToWorker(workerNodeKey
)
552 public setWorkerChoiceStrategyOptions (
553 workerChoiceStrategyOptions
: WorkerChoiceStrategyOptions
| undefined
555 this.checkValidWorkerChoiceStrategyOptions(workerChoiceStrategyOptions
)
556 if (workerChoiceStrategyOptions
!= null) {
557 this.opts
.workerChoiceStrategyOptions
= workerChoiceStrategyOptions
559 this.workerChoiceStrategyContext
?.setOptions(
560 this.opts
.workerChoiceStrategyOptions
565 public enableTasksQueue (
567 tasksQueueOptions
?: TasksQueueOptions
569 if (this.opts
.enableTasksQueue
=== true && !enable
) {
570 this.unsetTaskStealing()
571 this.unsetTasksStealingOnBackPressure()
572 this.flushTasksQueues()
574 this.opts
.enableTasksQueue
= enable
575 this.setTasksQueueOptions(tasksQueueOptions
)
579 public setTasksQueueOptions (
580 tasksQueueOptions
: TasksQueueOptions
| undefined
582 if (this.opts
.enableTasksQueue
=== true) {
583 checkValidTasksQueueOptions(tasksQueueOptions
)
584 this.opts
.tasksQueueOptions
=
585 this.buildTasksQueueOptions(tasksQueueOptions
)
586 // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
587 this.setTasksQueueSize(this.opts
.tasksQueueOptions
.size
!)
588 if (this.opts
.tasksQueueOptions
.taskStealing
=== true) {
589 this.unsetTaskStealing()
590 this.setTaskStealing()
592 this.unsetTaskStealing()
594 if (this.opts
.tasksQueueOptions
.tasksStealingOnBackPressure
=== true) {
595 this.unsetTasksStealingOnBackPressure()
596 this.setTasksStealingOnBackPressure()
598 this.unsetTasksStealingOnBackPressure()
600 } else if (this.opts
.tasksQueueOptions
!= null) {
601 delete this.opts
.tasksQueueOptions
605 private buildTasksQueueOptions (
606 tasksQueueOptions
: TasksQueueOptions
| undefined
607 ): TasksQueueOptions
{
609 ...getDefaultTasksQueueOptions(
610 this.maximumNumberOfWorkers
?? this.minimumNumberOfWorkers
616 private setTasksQueueSize (size
: number): void {
617 for (const workerNode
of this.workerNodes
) {
618 workerNode
.tasksQueueBackPressureSize
= size
622 private setTaskStealing (): void {
623 for (const [workerNodeKey
] of this.workerNodes
.entries()) {
624 this.workerNodes
[workerNodeKey
].on('idle', this.handleWorkerNodeIdleEvent
)
628 private unsetTaskStealing (): void {
629 for (const [workerNodeKey
] of this.workerNodes
.entries()) {
630 this.workerNodes
[workerNodeKey
].off(
632 this.handleWorkerNodeIdleEvent
637 private setTasksStealingOnBackPressure (): void {
638 for (const [workerNodeKey
] of this.workerNodes
.entries()) {
639 this.workerNodes
[workerNodeKey
].on(
641 this.handleWorkerNodeBackPressureEvent
646 private unsetTasksStealingOnBackPressure (): void {
647 for (const [workerNodeKey
] of this.workerNodes
.entries()) {
648 this.workerNodes
[workerNodeKey
].off(
650 this.handleWorkerNodeBackPressureEvent
656 * Whether the pool is full or not.
658 * The pool filling boolean status.
660 protected get
full (): boolean {
662 this.workerNodes
.length
>=
663 (this.maximumNumberOfWorkers
?? this.minimumNumberOfWorkers
)
668 * Whether the pool is busy or not.
670 * The pool busyness boolean status.
672 protected abstract get
busy (): boolean
675 * Whether worker nodes are executing concurrently their tasks quota or not.
677 * @returns Worker nodes busyness boolean status.
679 protected internalBusy (): boolean {
680 if (this.opts
.enableTasksQueue
=== true) {
682 this.workerNodes
.findIndex(
684 workerNode
.info
.ready
&&
685 workerNode
.usage
.tasks
.executing
<
686 // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
687 this.opts
.tasksQueueOptions
!.concurrency
!
692 this.workerNodes
.findIndex(
694 workerNode
.info
.ready
&& workerNode
.usage
.tasks
.executing
=== 0
699 private isWorkerNodeBusy (workerNodeKey
: number): boolean {
700 if (this.opts
.enableTasksQueue
=== true) {
702 this.workerNodes
[workerNodeKey
].usage
.tasks
.executing
>=
703 // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
704 this.opts
.tasksQueueOptions
!.concurrency
!
707 return this.workerNodes
[workerNodeKey
].usage
.tasks
.executing
> 0
710 private async sendTaskFunctionOperationToWorker (
711 workerNodeKey
: number,
712 message
: MessageValue
<Data
>
713 ): Promise
<boolean> {
714 return await new Promise
<boolean>((resolve
, reject
) => {
715 const taskFunctionOperationListener
= (
716 message
: MessageValue
<Response
>
718 this.checkMessageWorkerId(message
)
719 const workerId
= this.getWorkerInfo(workerNodeKey
)?.id
721 message
.taskFunctionOperationStatus
!= null &&
722 message
.workerId
=== workerId
724 if (message
.taskFunctionOperationStatus
) {
729 `Task function operation '${message.taskFunctionOperation}' failed on worker ${message.workerId} with error: '${message.workerError?.message}'`
733 this.deregisterWorkerMessageListener(
734 this.getWorkerNodeKeyByWorkerId(message
.workerId
),
735 taskFunctionOperationListener
739 this.registerWorkerMessageListener(
741 taskFunctionOperationListener
743 this.sendToWorker(workerNodeKey
, message
)
747 private async sendTaskFunctionOperationToWorkers (
748 message
: MessageValue
<Data
>
749 ): Promise
<boolean> {
750 return await new Promise
<boolean>((resolve
, reject
) => {
751 const responsesReceived
= new Array<MessageValue
<Response
>>()
752 const taskFunctionOperationsListener
= (
753 message
: MessageValue
<Response
>
755 this.checkMessageWorkerId(message
)
756 if (message
.taskFunctionOperationStatus
!= null) {
757 responsesReceived
.push(message
)
758 if (responsesReceived
.length
=== this.workerNodes
.length
) {
760 responsesReceived
.every(
761 message
=> message
.taskFunctionOperationStatus
=== true
766 responsesReceived
.some(
767 message
=> message
.taskFunctionOperationStatus
=== false
770 const errorResponse
= responsesReceived
.find(
771 response
=> response
.taskFunctionOperationStatus
=== false
775 `Task function operation '${
776 message.taskFunctionOperation as string
777 }' failed on worker ${errorResponse?.workerId} with error: '${
778 errorResponse?.workerError?.message
783 this.deregisterWorkerMessageListener(
784 this.getWorkerNodeKeyByWorkerId(message
.workerId
),
785 taskFunctionOperationsListener
790 for (const [workerNodeKey
] of this.workerNodes
.entries()) {
791 this.registerWorkerMessageListener(
793 taskFunctionOperationsListener
795 this.sendToWorker(workerNodeKey
, message
)
801 public hasTaskFunction (name
: string): boolean {
802 for (const workerNode
of this.workerNodes
) {
804 Array.isArray(workerNode
.info
.taskFunctionNames
) &&
805 workerNode
.info
.taskFunctionNames
.includes(name
)
814 public async addTaskFunction (
816 fn
: TaskFunction
<Data
, Response
>
817 ): Promise
<boolean> {
818 if (typeof name
!== 'string') {
819 throw new TypeError('name argument must be a string')
821 if (typeof name
=== 'string' && name
.trim().length
=== 0) {
822 throw new TypeError('name argument must not be an empty string')
824 if (typeof fn
!== 'function') {
825 throw new TypeError('fn argument must be a function')
827 const opResult
= await this.sendTaskFunctionOperationToWorkers({
828 taskFunctionOperation
: 'add',
829 taskFunctionName
: name
,
830 taskFunction
: fn
.toString()
832 this.taskFunctions
.set(name
, fn
)
837 public async removeTaskFunction (name
: string): Promise
<boolean> {
838 if (!this.taskFunctions
.has(name
)) {
840 'Cannot remove a task function not handled on the pool side'
843 const opResult
= await this.sendTaskFunctionOperationToWorkers({
844 taskFunctionOperation
: 'remove',
845 taskFunctionName
: name
847 this.deleteTaskFunctionWorkerUsages(name
)
848 this.taskFunctions
.delete(name
)
853 public listTaskFunctionNames (): string[] {
854 for (const workerNode
of this.workerNodes
) {
856 Array.isArray(workerNode
.info
.taskFunctionNames
) &&
857 workerNode
.info
.taskFunctionNames
.length
> 0
859 return workerNode
.info
.taskFunctionNames
866 public async setDefaultTaskFunction (name
: string): Promise
<boolean> {
867 return await this.sendTaskFunctionOperationToWorkers({
868 taskFunctionOperation
: 'default',
869 taskFunctionName
: name
873 private deleteTaskFunctionWorkerUsages (name
: string): void {
874 for (const workerNode
of this.workerNodes
) {
875 workerNode
.deleteTaskFunctionWorkerUsage(name
)
879 private shallExecuteTask (workerNodeKey
: number): boolean {
881 this.tasksQueueSize(workerNodeKey
) === 0 &&
882 this.workerNodes
[workerNodeKey
].usage
.tasks
.executing
<
883 // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
884 this.opts
.tasksQueueOptions
!.concurrency
!
889 public async execute (
892 transferList
?: TransferListItem
[]
893 ): Promise
<Response
> {
894 return await new Promise
<Response
>((resolve
, reject
) => {
896 reject(new Error('Cannot execute a task on not started pool'))
899 if (this.destroying
) {
900 reject(new Error('Cannot execute a task on destroying pool'))
903 if (name
!= null && typeof name
!== 'string') {
904 reject(new TypeError('name argument must be a string'))
909 typeof name
=== 'string' &&
910 name
.trim().length
=== 0
912 reject(new TypeError('name argument must not be an empty string'))
915 if (transferList
!= null && !Array.isArray(transferList
)) {
916 reject(new TypeError('transferList argument must be an array'))
919 const timestamp
= performance
.now()
920 const workerNodeKey
= this.chooseWorkerNode()
921 const task
: Task
<Data
> = {
922 name
: name
?? DEFAULT_TASK_NAME
,
923 // eslint-disable-next-line @typescript-eslint/consistent-type-assertions
924 data
: data
?? ({} as Data
),
929 // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
930 this.promiseResponseMap
.set(task
.taskId
!, {
934 ...(this.emitter
!= null && {
935 asyncResource
: new AsyncResource('poolifier:task', {
936 triggerAsyncId
: this.emitter
.asyncId
,
937 requireManualDestroy
: true
942 this.opts
.enableTasksQueue
=== false ||
943 (this.opts
.enableTasksQueue
=== true &&
944 this.shallExecuteTask(workerNodeKey
))
946 this.executeTask(workerNodeKey
, task
)
948 this.enqueueTask(workerNodeKey
, task
)
954 public start (): void {
956 throw new Error('Cannot start an already started pool')
959 throw new Error('Cannot start an already starting pool')
961 if (this.destroying
) {
962 throw new Error('Cannot start a destroying pool')
966 this.workerNodes
.reduce(
967 (accumulator
, workerNode
) =>
968 !workerNode
.info
.dynamic
? accumulator
+ 1 : accumulator
,
970 ) < this.minimumNumberOfWorkers
972 this.createAndSetupWorkerNode()
974 this.starting
= false
979 public async destroy (): Promise
<void> {
981 throw new Error('Cannot destroy an already destroyed pool')
984 throw new Error('Cannot destroy an starting pool')
986 if (this.destroying
) {
987 throw new Error('Cannot destroy an already destroying pool')
989 this.destroying
= true
991 this.workerNodes
.map(async (_workerNode
, workerNodeKey
) => {
992 await this.destroyWorkerNode(workerNodeKey
)
995 this.emitter
?.emit(PoolEvents
.destroy
, this.info
)
996 this.emitter
?.emitDestroy()
997 this.emitter
?.removeAllListeners()
998 this.readyEventEmitted
= false
999 this.destroying
= false
1000 this.started
= false
1003 private async sendKillMessageToWorker (workerNodeKey
: number): Promise
<void> {
1004 await new Promise
<void>((resolve
, reject
) => {
1005 // eslint-disable-next-line @typescript-eslint/no-unnecessary-condition
1006 if (this.workerNodes
[workerNodeKey
] == null) {
1010 const killMessageListener
= (message
: MessageValue
<Response
>): void => {
1011 this.checkMessageWorkerId(message
)
1012 if (message
.kill
=== 'success') {
1014 } else if (message
.kill
=== 'failure') {
1017 `Kill message handling failed on worker ${message.workerId}`
1022 // FIXME: should be registered only once
1023 this.registerWorkerMessageListener(workerNodeKey
, killMessageListener
)
1024 this.sendToWorker(workerNodeKey
, { kill
: true })
1029 * Terminates the worker node given its worker node key.
1031 * @param workerNodeKey - The worker node key.
1033 protected async destroyWorkerNode (workerNodeKey
: number): Promise
<void> {
1034 this.flagWorkerNodeAsNotReady(workerNodeKey
)
1035 const flushedTasks
= this.flushTasksQueue(workerNodeKey
)
1036 const workerNode
= this.workerNodes
[workerNodeKey
]
1037 await waitWorkerNodeEvents(
1041 this.opts
.tasksQueueOptions
?.tasksFinishedTimeout
??
1042 getDefaultTasksQueueOptions(
1043 this.maximumNumberOfWorkers
?? this.minimumNumberOfWorkers
1044 ).tasksFinishedTimeout
1046 await this.sendKillMessageToWorker(workerNodeKey
)
1047 await workerNode
.terminate()
1051 * Setup hook to execute code before worker nodes are created in the abstract constructor.
1052 * Can be overridden.
1056 protected setupHook (): void {
1057 /* Intentionally empty */
1061 * Should return whether the worker is the main worker or not.
1063 protected abstract isMain (): boolean
1066 * Hook executed before the worker task execution.
1067 * Can be overridden.
1069 * @param workerNodeKey - The worker node key.
1070 * @param task - The task to execute.
1072 protected beforeTaskExecutionHook (
1073 workerNodeKey
: number,
1076 // eslint-disable-next-line @typescript-eslint/no-unnecessary-condition
1077 if (this.workerNodes
[workerNodeKey
]?.usage
!= null) {
1078 const workerUsage
= this.workerNodes
[workerNodeKey
].usage
1079 ++workerUsage
.tasks
.executing
1080 updateWaitTimeWorkerUsage(
1081 this.workerChoiceStrategyContext
,
1087 this.shallUpdateTaskFunctionWorkerUsage(workerNodeKey
) &&
1088 // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
1089 this.workerNodes
[workerNodeKey
].getTaskFunctionWorkerUsage(task
.name
!) !=
1092 // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
1093 const taskFunctionWorkerUsage
= this.workerNodes
[
1095 // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
1096 ].getTaskFunctionWorkerUsage(task
.name
!)!
1097 ++taskFunctionWorkerUsage
.tasks
.executing
1098 updateWaitTimeWorkerUsage(
1099 this.workerChoiceStrategyContext
,
1100 taskFunctionWorkerUsage
,
1107 * Hook executed after the worker task execution.
1108 * Can be overridden.
1110 * @param workerNodeKey - The worker node key.
1111 * @param message - The received message.
1113 protected afterTaskExecutionHook (
1114 workerNodeKey
: number,
1115 message
: MessageValue
<Response
>
1117 let needWorkerChoiceStrategyUpdate
= false
1118 // eslint-disable-next-line @typescript-eslint/no-unnecessary-condition
1119 if (this.workerNodes
[workerNodeKey
]?.usage
!= null) {
1120 const workerUsage
= this.workerNodes
[workerNodeKey
].usage
1121 updateTaskStatisticsWorkerUsage(workerUsage
, message
)
1122 updateRunTimeWorkerUsage(
1123 this.workerChoiceStrategyContext
,
1127 updateEluWorkerUsage(
1128 this.workerChoiceStrategyContext
,
1132 needWorkerChoiceStrategyUpdate
= true
1135 this.shallUpdateTaskFunctionWorkerUsage(workerNodeKey
) &&
1136 this.workerNodes
[workerNodeKey
].getTaskFunctionWorkerUsage(
1137 // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
1138 message
.taskPerformance
!.name
1141 // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
1142 const taskFunctionWorkerUsage
= this.workerNodes
[
1144 // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
1145 ].getTaskFunctionWorkerUsage(message
.taskPerformance
!.name
)!
1146 updateTaskStatisticsWorkerUsage(taskFunctionWorkerUsage
, message
)
1147 updateRunTimeWorkerUsage(
1148 this.workerChoiceStrategyContext
,
1149 taskFunctionWorkerUsage
,
1152 updateEluWorkerUsage(
1153 this.workerChoiceStrategyContext
,
1154 taskFunctionWorkerUsage
,
1157 needWorkerChoiceStrategyUpdate
= true
1159 if (needWorkerChoiceStrategyUpdate
) {
1160 this.workerChoiceStrategyContext
?.update(workerNodeKey
)
1165 * Whether the worker node shall update its task function worker usage or not.
1167 * @param workerNodeKey - The worker node key.
1168 * @returns `true` if the worker node shall update its task function worker usage, `false` otherwise.
1170 private shallUpdateTaskFunctionWorkerUsage (workerNodeKey
: number): boolean {
1171 const workerInfo
= this.getWorkerInfo(workerNodeKey
)
1173 workerInfo
!= null &&
1174 Array.isArray(workerInfo
.taskFunctionNames
) &&
1175 workerInfo
.taskFunctionNames
.length
> 2
1180 * Chooses a worker node for the next task.
1182 * The default worker choice strategy uses a round robin algorithm to distribute the tasks.
1184 * @returns The chosen worker node key
1186 private chooseWorkerNode (): number {
1187 if (this.shallCreateDynamicWorker()) {
1188 const workerNodeKey
= this.createAndSetupDynamicWorkerNode()
1190 this.workerChoiceStrategyContext
?.getStrategyPolicy()
1191 .dynamicWorkerUsage
=== true
1193 return workerNodeKey
1196 // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
1197 return this.workerChoiceStrategyContext
!.execute()
1201 * Conditions for dynamic worker creation.
1203 * @returns Whether to create a dynamic worker or not.
1205 protected abstract shallCreateDynamicWorker (): boolean
1208 * Sends a message to worker given its worker node key.
1210 * @param workerNodeKey - The worker node key.
1211 * @param message - The message.
1212 * @param transferList - The optional array of transferable objects.
1214 protected abstract sendToWorker (
1215 workerNodeKey
: number,
1216 message
: MessageValue
<Data
>,
1217 transferList
?: TransferListItem
[]
1221 * Creates a new, completely set up worker node.
1223 * @returns New, completely set up worker node key.
1225 protected createAndSetupWorkerNode (): number {
1226 const workerNode
= this.createWorkerNode()
1227 workerNode
.registerWorkerEventHandler(
1229 this.opts
.onlineHandler
?? EMPTY_FUNCTION
1231 workerNode
.registerWorkerEventHandler(
1233 this.opts
.messageHandler
?? EMPTY_FUNCTION
1235 workerNode
.registerWorkerEventHandler(
1237 this.opts
.errorHandler
?? EMPTY_FUNCTION
1239 workerNode
.registerWorkerEventHandler('error', (error
: Error) => {
1240 workerNode
.info
.ready
= false
1241 this.emitter
?.emit(PoolEvents
.error
, error
)
1245 this.opts
.restartWorkerOnError
=== true
1247 if (workerNode
.info
.dynamic
) {
1248 this.createAndSetupDynamicWorkerNode()
1250 this.createAndSetupWorkerNode()
1256 this.opts
.enableTasksQueue
=== true
1258 this.redistributeQueuedTasks(this.workerNodes
.indexOf(workerNode
))
1260 // eslint-disable-next-line @typescript-eslint/no-unnecessary-condition
1261 workerNode
?.terminate().catch(error
=> {
1262 this.emitter
?.emit(PoolEvents
.error
, error
)
1265 workerNode
.registerWorkerEventHandler(
1267 this.opts
.exitHandler
?? EMPTY_FUNCTION
1269 workerNode
.registerOnceWorkerEventHandler('exit', () => {
1270 this.removeWorkerNode(workerNode
)
1272 const workerNodeKey
= this.addWorkerNode(workerNode
)
1273 this.afterWorkerNodeSetup(workerNodeKey
)
1274 return workerNodeKey
1278 * Creates a new, completely set up dynamic worker node.
1280 * @returns New, completely set up dynamic worker node key.
1282 protected createAndSetupDynamicWorkerNode (): number {
1283 const workerNodeKey
= this.createAndSetupWorkerNode()
1284 this.registerWorkerMessageListener(workerNodeKey
, message
=> {
1285 this.checkMessageWorkerId(message
)
1286 const localWorkerNodeKey
= this.getWorkerNodeKeyByWorkerId(
1289 const workerUsage
= this.workerNodes
[localWorkerNodeKey
]?.usage
1290 // Kill message received from worker
1292 isKillBehavior(KillBehaviors
.HARD
, message
.kill
) ||
1293 (isKillBehavior(KillBehaviors
.SOFT
, message
.kill
) &&
1294 ((this.opts
.enableTasksQueue
=== false &&
1295 workerUsage
.tasks
.executing
=== 0) ||
1296 (this.opts
.enableTasksQueue
=== true &&
1297 workerUsage
.tasks
.executing
=== 0 &&
1298 this.tasksQueueSize(localWorkerNodeKey
) === 0)))
1300 // Flag the worker node as not ready immediately
1301 this.flagWorkerNodeAsNotReady(localWorkerNodeKey
)
1302 this.destroyWorkerNode(localWorkerNodeKey
).catch(error
=> {
1303 this.emitter
?.emit(PoolEvents
.error
, error
)
1307 this.sendToWorker(workerNodeKey
, {
1310 if (this.taskFunctions
.size
> 0) {
1311 for (const [taskFunctionName
, taskFunction
] of this.taskFunctions
) {
1312 this.sendTaskFunctionOperationToWorker(workerNodeKey
, {
1313 taskFunctionOperation
: 'add',
1315 taskFunction
: taskFunction
.toString()
1317 this.emitter
?.emit(PoolEvents
.error
, error
)
1321 const workerNode
= this.workerNodes
[workerNodeKey
]
1322 workerNode
.info
.dynamic
= true
1324 this.workerChoiceStrategyContext
?.getStrategyPolicy()
1325 .dynamicWorkerReady
=== true ||
1326 this.workerChoiceStrategyContext
?.getStrategyPolicy()
1327 .dynamicWorkerUsage
=== true
1329 workerNode
.info
.ready
= true
1331 this.checkAndEmitDynamicWorkerCreationEvents()
1332 return workerNodeKey
1336 * Registers a listener callback on the worker given its worker node key.
1338 * @param workerNodeKey - The worker node key.
1339 * @param listener - The message listener callback.
1341 protected abstract registerWorkerMessageListener
<
1342 Message
extends Data
| Response
1344 workerNodeKey
: number,
1345 listener
: (message
: MessageValue
<Message
>) => void
1349 * Registers once a listener callback on the worker given its worker node key.
1351 * @param workerNodeKey - The worker node key.
1352 * @param listener - The message listener callback.
1354 protected abstract registerOnceWorkerMessageListener
<
1355 Message
extends Data
| Response
1357 workerNodeKey
: number,
1358 listener
: (message
: MessageValue
<Message
>) => void
1362 * Deregisters a listener callback on the worker given its worker node key.
1364 * @param workerNodeKey - The worker node key.
1365 * @param listener - The message listener callback.
1367 protected abstract deregisterWorkerMessageListener
<
1368 Message
extends Data
| Response
1370 workerNodeKey
: number,
1371 listener
: (message
: MessageValue
<Message
>) => void
1375 * Method hooked up after a worker node has been newly created.
1376 * Can be overridden.
1378 * @param workerNodeKey - The newly created worker node key.
1380 protected afterWorkerNodeSetup (workerNodeKey
: number): void {
1381 // Listen to worker messages.
1382 this.registerWorkerMessageListener(
1384 this.workerMessageListener
1386 // Send the startup message to worker.
1387 this.sendStartupMessageToWorker(workerNodeKey
)
1388 // Send the statistics message to worker.
1389 this.sendStatisticsMessageToWorker(workerNodeKey
)
1390 if (this.opts
.enableTasksQueue
=== true) {
1391 if (this.opts
.tasksQueueOptions
?.taskStealing
=== true) {
1392 this.workerNodes
[workerNodeKey
].on(
1394 this.handleWorkerNodeIdleEvent
1397 if (this.opts
.tasksQueueOptions
?.tasksStealingOnBackPressure
=== true) {
1398 this.workerNodes
[workerNodeKey
].on(
1400 this.handleWorkerNodeBackPressureEvent
1407 * Sends the startup message to worker given its worker node key.
1409 * @param workerNodeKey - The worker node key.
1411 protected abstract sendStartupMessageToWorker (workerNodeKey
: number): void
1414 * Sends the statistics message to worker given its worker node key.
1416 * @param workerNodeKey - The worker node key.
1418 private sendStatisticsMessageToWorker (workerNodeKey
: number): void {
1419 this.sendToWorker(workerNodeKey
, {
1422 this.workerChoiceStrategyContext
?.getTaskStatisticsRequirements()
1423 ?.runTime
.aggregate
?? false,
1425 this.workerChoiceStrategyContext
?.getTaskStatisticsRequirements()?.elu
1431 private cannotStealTask (): boolean {
1432 return this.workerNodes
.length
<= 1 || this.info
.queuedTasks
=== 0
1435 private handleTask (workerNodeKey
: number, task
: Task
<Data
>): void {
1436 if (this.shallExecuteTask(workerNodeKey
)) {
1437 this.executeTask(workerNodeKey
, task
)
1439 this.enqueueTask(workerNodeKey
, task
)
1443 private redistributeQueuedTasks (workerNodeKey
: number): void {
1444 if (workerNodeKey
=== -1 || this.cannotStealTask()) {
1447 while (this.tasksQueueSize(workerNodeKey
) > 0) {
1448 const destinationWorkerNodeKey
= this.workerNodes
.reduce(
1449 (minWorkerNodeKey
, workerNode
, workerNodeKey
, workerNodes
) => {
1450 return workerNode
.info
.ready
&&
1451 workerNode
.usage
.tasks
.queued
<
1452 workerNodes
[minWorkerNodeKey
].usage
.tasks
.queued
1459 destinationWorkerNodeKey
,
1460 // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
1461 this.dequeueTask(workerNodeKey
)!
1466 private updateTaskStolenStatisticsWorkerUsage (
1467 workerNodeKey
: number,
1470 const workerNode
= this.workerNodes
[workerNodeKey
]
1471 // eslint-disable-next-line @typescript-eslint/no-unnecessary-condition
1472 if (workerNode
?.usage
!= null) {
1473 ++workerNode
.usage
.tasks
.stolen
1476 this.shallUpdateTaskFunctionWorkerUsage(workerNodeKey
) &&
1477 workerNode
.getTaskFunctionWorkerUsage(taskName
) != null
1479 const taskFunctionWorkerUsage
=
1480 // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
1481 workerNode
.getTaskFunctionWorkerUsage(taskName
)!
1482 ++taskFunctionWorkerUsage
.tasks
.stolen
1486 private updateTaskSequentiallyStolenStatisticsWorkerUsage (
1487 workerNodeKey
: number
1489 const workerNode
= this.workerNodes
[workerNodeKey
]
1490 // eslint-disable-next-line @typescript-eslint/no-unnecessary-condition
1491 if (workerNode
?.usage
!= null) {
1492 ++workerNode
.usage
.tasks
.sequentiallyStolen
1496 private updateTaskSequentiallyStolenStatisticsTaskFunctionWorkerUsage (
1497 workerNodeKey
: number,
1500 const workerNode
= this.workerNodes
[workerNodeKey
]
1502 this.shallUpdateTaskFunctionWorkerUsage(workerNodeKey
) &&
1503 workerNode
.getTaskFunctionWorkerUsage(taskName
) != null
1505 const taskFunctionWorkerUsage
=
1506 // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
1507 workerNode
.getTaskFunctionWorkerUsage(taskName
)!
1508 ++taskFunctionWorkerUsage
.tasks
.sequentiallyStolen
1512 private resetTaskSequentiallyStolenStatisticsWorkerUsage (
1513 workerNodeKey
: number
1515 const workerNode
= this.workerNodes
[workerNodeKey
]
1516 // eslint-disable-next-line @typescript-eslint/no-unnecessary-condition
1517 if (workerNode
?.usage
!= null) {
1518 workerNode
.usage
.tasks
.sequentiallyStolen
= 0
1522 private resetTaskSequentiallyStolenStatisticsTaskFunctionWorkerUsage (
1523 workerNodeKey
: number,
1526 const workerNode
= this.workerNodes
[workerNodeKey
]
1528 this.shallUpdateTaskFunctionWorkerUsage(workerNodeKey
) &&
1529 workerNode
.getTaskFunctionWorkerUsage(taskName
) != null
1531 const taskFunctionWorkerUsage
=
1532 // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
1533 workerNode
.getTaskFunctionWorkerUsage(taskName
)!
1534 taskFunctionWorkerUsage
.tasks
.sequentiallyStolen
= 0
1538 private readonly handleWorkerNodeIdleEvent
= (
1539 eventDetail
: WorkerNodeEventDetail
,
1540 previousStolenTask
?: Task
<Data
>
1542 const { workerNodeKey
} = eventDetail
1543 if (workerNodeKey
== null) {
1545 "WorkerNode event detail 'workerNodeKey' property must be defined"
1548 const workerInfo
= this.getWorkerInfo(workerNodeKey
)
1550 this.cannotStealTask() ||
1551 (this.info
.stealingWorkerNodes
?? 0) >
1552 Math.floor(this.workerNodes
.length
/ 2)
1554 if (workerInfo
!= null && previousStolenTask
!= null) {
1555 workerInfo
.stealing
= false
1559 const workerNodeTasksUsage
= this.workerNodes
[workerNodeKey
].usage
.tasks
1561 workerInfo
!= null &&
1562 previousStolenTask
!= null &&
1563 workerNodeTasksUsage
.sequentiallyStolen
> 0 &&
1564 (workerNodeTasksUsage
.executing
> 0 ||
1565 this.tasksQueueSize(workerNodeKey
) > 0)
1567 workerInfo
.stealing
= false
1568 // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
1569 for (const taskName
of this.workerNodes
[workerNodeKey
].info
1570 .taskFunctionNames
!) {
1571 this.resetTaskSequentiallyStolenStatisticsTaskFunctionWorkerUsage(
1576 this.resetTaskSequentiallyStolenStatisticsWorkerUsage(workerNodeKey
)
1579 if (workerInfo
== null) {
1581 `Worker node with key '${workerNodeKey}' not found in pool`
1584 workerInfo
.stealing
= true
1585 const stolenTask
= this.workerNodeStealTask(workerNodeKey
)
1587 this.shallUpdateTaskFunctionWorkerUsage(workerNodeKey
) &&
1590 // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
1591 const taskFunctionTasksWorkerUsage
= this.workerNodes
[
1593 // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
1594 ].getTaskFunctionWorkerUsage(stolenTask
.name
!)!.tasks
1596 taskFunctionTasksWorkerUsage
.sequentiallyStolen
=== 0 ||
1597 (previousStolenTask
!= null &&
1598 previousStolenTask
.name
=== stolenTask
.name
&&
1599 taskFunctionTasksWorkerUsage
.sequentiallyStolen
> 0)
1601 this.updateTaskSequentiallyStolenStatisticsTaskFunctionWorkerUsage(
1603 // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
1607 this.resetTaskSequentiallyStolenStatisticsTaskFunctionWorkerUsage(
1609 // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
1614 sleep(exponentialDelay(workerNodeTasksUsage
.sequentiallyStolen
))
1616 this.handleWorkerNodeIdleEvent(eventDetail
, stolenTask
)
1620 this.emitter
?.emit(PoolEvents
.error
, error
)
1624 private readonly workerNodeStealTask
= (
1625 workerNodeKey
: number
1626 ): Task
<Data
> | undefined => {
1627 const workerNodes
= this.workerNodes
1630 (workerNodeA
, workerNodeB
) =>
1631 workerNodeB
.usage
.tasks
.queued
- workerNodeA
.usage
.tasks
.queued
1633 const sourceWorkerNode
= workerNodes
.find(
1634 (sourceWorkerNode
, sourceWorkerNodeKey
) =>
1635 sourceWorkerNode
.info
.ready
&&
1636 !sourceWorkerNode
.info
.stealing
&&
1637 sourceWorkerNodeKey
!== workerNodeKey
&&
1638 sourceWorkerNode
.usage
.tasks
.queued
> 0
1640 if (sourceWorkerNode
!= null) {
1641 // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
1642 const task
= sourceWorkerNode
.popTask()!
1643 this.handleTask(workerNodeKey
, task
)
1644 this.updateTaskSequentiallyStolenStatisticsWorkerUsage(workerNodeKey
)
1645 // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
1646 this.updateTaskStolenStatisticsWorkerUsage(workerNodeKey
, task
.name
!)
1651 private readonly handleWorkerNodeBackPressureEvent
= (
1652 eventDetail
: WorkerNodeEventDetail
1655 this.cannotStealTask() ||
1656 (this.info
.stealingWorkerNodes
?? 0) >
1657 Math.floor(this.workerNodes
.length
/ 2)
1661 const { workerId
} = eventDetail
1662 const sizeOffset
= 1
1663 // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
1664 if (this.opts
.tasksQueueOptions
!.size
! <= sizeOffset
) {
1667 const sourceWorkerNode
=
1668 this.workerNodes
[this.getWorkerNodeKeyByWorkerId(workerId
)]
1669 const workerNodes
= this.workerNodes
1672 (workerNodeA
, workerNodeB
) =>
1673 workerNodeA
.usage
.tasks
.queued
- workerNodeB
.usage
.tasks
.queued
1675 for (const [workerNodeKey
, workerNode
] of workerNodes
.entries()) {
1677 sourceWorkerNode
.usage
.tasks
.queued
> 0 &&
1678 workerNode
.info
.ready
&&
1679 !workerNode
.info
.stealing
&&
1680 workerNode
.info
.id
!== workerId
&&
1681 workerNode
.usage
.tasks
.queued
<
1682 // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
1683 this.opts
.tasksQueueOptions
!.size
! - sizeOffset
1685 const workerInfo
= this.getWorkerInfo(workerNodeKey
)
1686 if (workerInfo
== null) {
1688 `Worker node with key '${workerNodeKey}' not found in pool`
1691 workerInfo
.stealing
= true
1692 // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
1693 const task
= sourceWorkerNode
.popTask()!
1694 this.handleTask(workerNodeKey
, task
)
1695 // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
1696 this.updateTaskStolenStatisticsWorkerUsage(workerNodeKey
, task
.name
!)
1697 workerInfo
.stealing
= false
1703 * This method is the message listener registered on each worker.
1705 protected readonly workerMessageListener
= (
1706 message
: MessageValue
<Response
>
1708 this.checkMessageWorkerId(message
)
1709 const { workerId
, ready
, taskId
, taskFunctionNames
} = message
1710 if (ready
!= null && taskFunctionNames
!= null) {
1711 // Worker ready response received from worker
1712 this.handleWorkerReadyResponse(message
)
1713 } else if (taskId
!= null) {
1714 // Task execution response received from worker
1715 this.handleTaskExecutionResponse(message
)
1716 } else if (taskFunctionNames
!= null) {
1717 // Task function names message received from worker
1718 const workerInfo
= this.getWorkerInfo(
1719 this.getWorkerNodeKeyByWorkerId(workerId
)
1721 if (workerInfo
!= null) {
1722 workerInfo
.taskFunctionNames
= taskFunctionNames
1727 private checkAndEmitReadyEvent (): void {
1728 if (!this.readyEventEmitted
&& this.ready
) {
1729 this.emitter
?.emit(PoolEvents
.ready
, this.info
)
1730 this.readyEventEmitted
= true
1734 private handleWorkerReadyResponse (message
: MessageValue
<Response
>): void {
1735 const { workerId
, ready
, taskFunctionNames
} = message
1736 if (ready
== null || !ready
) {
1737 throw new Error(`Worker ${workerId} failed to initialize`)
1740 this.workerNodes
[this.getWorkerNodeKeyByWorkerId(workerId
)]
1741 workerNode
.info
.ready
= ready
1742 workerNode
.info
.taskFunctionNames
= taskFunctionNames
1743 this.checkAndEmitReadyEvent()
1746 private handleTaskExecutionResponse (message
: MessageValue
<Response
>): void {
1747 const { workerId
, taskId
, workerError
, data
} = message
1748 // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
1749 const promiseResponse
= this.promiseResponseMap
.get(taskId
!)
1750 if (promiseResponse
!= null) {
1751 const { resolve
, reject
, workerNodeKey
, asyncResource
} = promiseResponse
1752 const workerNode
= this.workerNodes
[workerNodeKey
]
1753 if (workerError
!= null) {
1754 this.emitter
?.emit(PoolEvents
.taskError
, workerError
)
1755 asyncResource
!= null
1756 ? asyncResource
.runInAsyncScope(
1761 : reject(workerError
.message
)
1763 asyncResource
!= null
1764 ? asyncResource
.runInAsyncScope(resolve
, this.emitter
, data
)
1765 : resolve(data
as Response
)
1767 asyncResource
?.emitDestroy()
1768 this.afterTaskExecutionHook(workerNodeKey
, message
)
1769 // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
1770 this.promiseResponseMap
.delete(taskId
!)
1771 // eslint-disable-next-line @typescript-eslint/no-unnecessary-condition
1772 workerNode
?.emit('taskFinished', taskId
)
1773 if (this.opts
.enableTasksQueue
=== true && !this.destroying
) {
1774 const workerNodeTasksUsage
= workerNode
.usage
.tasks
1776 this.tasksQueueSize(workerNodeKey
) > 0 &&
1777 workerNodeTasksUsage
.executing
<
1778 // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
1779 this.opts
.tasksQueueOptions
!.concurrency
!
1781 // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
1782 this.executeTask(workerNodeKey
, this.dequeueTask(workerNodeKey
)!)
1785 workerNodeTasksUsage
.executing
=== 0 &&
1786 this.tasksQueueSize(workerNodeKey
) === 0 &&
1787 workerNodeTasksUsage
.sequentiallyStolen
=== 0
1789 workerNode
.emit('idle', {
1798 private checkAndEmitTaskExecutionEvents (): void {
1800 this.emitter
?.emit(PoolEvents
.busy
, this.info
)
1804 private checkAndEmitTaskQueuingEvents (): void {
1805 if (this.hasBackPressure()) {
1806 this.emitter
?.emit(PoolEvents
.backPressure
, this.info
)
1811 * Emits dynamic worker creation events.
1813 protected abstract checkAndEmitDynamicWorkerCreationEvents (): void
1816 * Gets the worker information given its worker node key.
1818 * @param workerNodeKey - The worker node key.
1819 * @returns The worker information.
1821 protected getWorkerInfo (workerNodeKey
: number): WorkerInfo
| undefined {
1822 return this.workerNodes
[workerNodeKey
]?.info
1826 * Creates a worker node.
1828 * @returns The created worker node.
1830 private createWorkerNode (): IWorkerNode
<Worker
, Data
> {
1831 const workerNode
= new WorkerNode
<Worker
, Data
>(
1836 workerOptions
: this.opts
.workerOptions
,
1837 tasksQueueBackPressureSize
:
1838 this.opts
.tasksQueueOptions
?.size
??
1839 getDefaultTasksQueueOptions(
1840 this.maximumNumberOfWorkers
?? this.minimumNumberOfWorkers
1844 // Flag the worker node as ready at pool startup.
1845 if (this.starting
) {
1846 workerNode
.info
.ready
= true
1852 * Adds the given worker node in the pool worker nodes.
1854 * @param workerNode - The worker node.
1855 * @returns The added worker node key.
1856 * @throws {@link https://nodejs.org/api/errors.html#class-error} If the added worker node is not found.
1858 private addWorkerNode (workerNode
: IWorkerNode
<Worker
, Data
>): number {
1859 this.workerNodes
.push(workerNode
)
1860 const workerNodeKey
= this.workerNodes
.indexOf(workerNode
)
1861 if (workerNodeKey
=== -1) {
1862 throw new Error('Worker added not found in worker nodes')
1864 return workerNodeKey
1867 private checkAndEmitEmptyEvent (): void {
1869 this.emitter
?.emit(PoolEvents
.empty
, this.info
)
1870 this.readyEventEmitted
= false
1875 * Removes the worker node from the pool worker nodes.
1877 * @param workerNode - The worker node.
1879 private removeWorkerNode (workerNode
: IWorkerNode
<Worker
, Data
>): void {
1880 const workerNodeKey
= this.workerNodes
.indexOf(workerNode
)
1881 if (workerNodeKey
!== -1) {
1882 this.workerNodes
.splice(workerNodeKey
, 1)
1883 this.workerChoiceStrategyContext
?.remove(workerNodeKey
)
1885 this.checkAndEmitEmptyEvent()
1888 protected flagWorkerNodeAsNotReady (workerNodeKey
: number): void {
1889 const workerInfo
= this.getWorkerInfo(workerNodeKey
)
1890 if (workerInfo
!= null) {
1891 workerInfo
.ready
= false
1895 private hasBackPressure (): boolean {
1897 this.opts
.enableTasksQueue
=== true &&
1898 this.workerNodes
.findIndex(
1899 workerNode
=> !workerNode
.hasBackPressure()
1905 * Executes the given task on the worker given its worker node key.
1907 * @param workerNodeKey - The worker node key.
1908 * @param task - The task to execute.
1910 private executeTask (workerNodeKey
: number, task
: Task
<Data
>): void {
1911 this.beforeTaskExecutionHook(workerNodeKey
, task
)
1912 this.sendToWorker(workerNodeKey
, task
, task
.transferList
)
1913 this.checkAndEmitTaskExecutionEvents()
1916 private enqueueTask (workerNodeKey
: number, task
: Task
<Data
>): number {
1917 const tasksQueueSize
= this.workerNodes
[workerNodeKey
].enqueueTask(task
)
1918 this.checkAndEmitTaskQueuingEvents()
1919 return tasksQueueSize
1922 private dequeueTask (workerNodeKey
: number): Task
<Data
> | undefined {
1923 return this.workerNodes
[workerNodeKey
].dequeueTask()
1926 private tasksQueueSize (workerNodeKey
: number): number {
1927 return this.workerNodes
[workerNodeKey
].tasksQueueSize()
1930 protected flushTasksQueue (workerNodeKey
: number): number {
1931 let flushedTasks
= 0
1932 while (this.tasksQueueSize(workerNodeKey
) > 0) {
1933 // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
1934 this.executeTask(workerNodeKey
, this.dequeueTask(workerNodeKey
)!)
1937 this.workerNodes
[workerNodeKey
].clearTasksQueue()
1941 private flushTasksQueues (): void {
1942 for (const [workerNodeKey
] of this.workerNodes
.entries()) {
1943 this.flushTasksQueue(workerNodeKey
)