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 (minimumNumberOfWorkers
: number): void {
193 if (minimumNumberOfWorkers
== null) {
195 'Cannot instantiate a pool without specifying the number of workers'
197 } else if (!Number.isSafeInteger(minimumNumberOfWorkers
)) {
199 'Cannot instantiate a pool with a non safe integer number of workers'
201 } else if (minimumNumberOfWorkers
< 0) {
202 throw new RangeError(
203 'Cannot instantiate a pool with a negative number of workers'
205 } else if (this.type === PoolTypes
.fixed
&& minimumNumberOfWorkers
=== 0) {
206 throw new RangeError('Cannot instantiate a fixed pool with zero worker')
210 private checkPoolOptions (opts
: PoolOptions
<Worker
>): void {
211 if (isPlainObject(opts
)) {
212 this.opts
.startWorkers
= opts
.startWorkers
?? true
213 // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
214 checkValidWorkerChoiceStrategy(opts
.workerChoiceStrategy
!)
215 this.opts
.workerChoiceStrategy
=
216 opts
.workerChoiceStrategy
?? WorkerChoiceStrategies
.ROUND_ROBIN
217 this.checkValidWorkerChoiceStrategyOptions(
218 // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
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 // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
229 checkValidTasksQueueOptions(opts
.tasksQueueOptions
!)
230 this.opts
.tasksQueueOptions
= this.buildTasksQueueOptions(
231 // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
232 opts
.tasksQueueOptions
!
236 throw new TypeError('Invalid pool options: must be a plain object')
240 private checkValidWorkerChoiceStrategyOptions (
241 workerChoiceStrategyOptions
: WorkerChoiceStrategyOptions
244 workerChoiceStrategyOptions
!= null &&
245 !isPlainObject(workerChoiceStrategyOptions
)
248 'Invalid worker choice strategy options: must be a plain object'
252 workerChoiceStrategyOptions
?.weights
!= null &&
253 Object.keys(workerChoiceStrategyOptions
.weights
).length
!==
254 (this.maximumNumberOfWorkers
?? this.minimumNumberOfWorkers
)
257 'Invalid worker choice strategy options: must have a weight for each worker node'
261 workerChoiceStrategyOptions
?.measurement
!= null &&
262 !Object.values(Measurements
).includes(
263 workerChoiceStrategyOptions
.measurement
267 `Invalid worker choice strategy options: invalid measurement '${workerChoiceStrategyOptions.measurement}'`
272 private initializeEventEmitter (): void {
273 this.emitter
= new EventEmitterAsyncResource({
274 name
: `poolifier:${this.type}-${this.worker}-pool`
279 public get
info (): PoolInfo
{
284 started
: this.started
,
286 // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
287 strategy
: this.opts
.workerChoiceStrategy
!,
288 minSize
: this.minimumNumberOfWorkers
,
289 maxSize
: this.maximumNumberOfWorkers
?? this.minimumNumberOfWorkers
,
290 ...(this.workerChoiceStrategyContext
?.getTaskStatisticsRequirements()
291 .runTime
.aggregate
&&
292 this.workerChoiceStrategyContext
?.getTaskStatisticsRequirements()
293 .waitTime
.aggregate
&& { 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
&& {
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
&& {
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
542 this.checkValidWorkerChoiceStrategyOptions(workerChoiceStrategyOptions
)
543 if (workerChoiceStrategyOptions
!= null) {
544 this.opts
.workerChoiceStrategyOptions
= workerChoiceStrategyOptions
546 this.workerChoiceStrategyContext
.setOptions(
548 this.opts
.workerChoiceStrategyOptions
553 public enableTasksQueue (
555 tasksQueueOptions
?: TasksQueueOptions
557 if (this.opts
.enableTasksQueue
=== true && !enable
) {
558 this.unsetTaskStealing()
559 this.unsetTasksStealingOnBackPressure()
560 this.flushTasksQueues()
562 this.opts
.enableTasksQueue
= enable
563 // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
564 this.setTasksQueueOptions(tasksQueueOptions
!)
568 public setTasksQueueOptions (tasksQueueOptions
: TasksQueueOptions
): void {
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
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(
613 this.handleIdleWorkerNodeEvent
618 private unsetTaskStealing (): void {
619 for (const [workerNodeKey
] of this.workerNodes
.entries()) {
620 this.workerNodes
[workerNodeKey
].off(
622 this.handleIdleWorkerNodeEvent
627 private setTasksStealingOnBackPressure (): void {
628 for (const [workerNodeKey
] of this.workerNodes
.entries()) {
629 this.workerNodes
[workerNodeKey
].on(
631 this.handleBackPressureEvent
636 private unsetTasksStealingOnBackPressure (): void {
637 for (const [workerNodeKey
] of this.workerNodes
.entries()) {
638 this.workerNodes
[workerNodeKey
].off(
640 this.handleBackPressureEvent
646 * Whether the pool is full or not.
648 * The pool filling boolean status.
650 protected get
full (): boolean {
652 this.workerNodes
.length
>=
653 (this.maximumNumberOfWorkers
?? this.minimumNumberOfWorkers
)
658 * Whether the pool is busy or not.
660 * The pool busyness boolean status.
662 protected abstract get
busy (): boolean
665 * Whether worker nodes are executing concurrently their tasks quota or not.
667 * @returns Worker nodes busyness boolean status.
669 protected internalBusy (): boolean {
670 if (this.opts
.enableTasksQueue
=== true) {
672 this.workerNodes
.findIndex(
674 workerNode
.info
.ready
&&
675 workerNode
.usage
.tasks
.executing
<
676 // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
677 this.opts
.tasksQueueOptions
!.concurrency
!
682 this.workerNodes
.findIndex(
684 workerNode
.info
.ready
&& workerNode
.usage
.tasks
.executing
=== 0
689 private isWorkerNodeBusy (workerNodeKey
: number): boolean {
690 if (this.opts
.enableTasksQueue
=== true) {
692 this.workerNodes
[workerNodeKey
].usage
.tasks
.executing
>=
693 // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
694 this.opts
.tasksQueueOptions
!.concurrency
!
697 return this.workerNodes
[workerNodeKey
].usage
.tasks
.executing
> 0
700 private async sendTaskFunctionOperationToWorker (
701 workerNodeKey
: number,
702 message
: MessageValue
<Data
>
703 ): Promise
<boolean> {
704 return await new Promise
<boolean>((resolve
, reject
) => {
705 const taskFunctionOperationListener
= (
706 message
: MessageValue
<Response
>
708 this.checkMessageWorkerId(message
)
709 // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
710 const workerId
= this.getWorkerInfo(workerNodeKey
).id
!
712 message
.taskFunctionOperationStatus
!= null &&
713 message
.workerId
=== workerId
715 if (message
.taskFunctionOperationStatus
) {
717 } else if (!message
.taskFunctionOperationStatus
) {
720 `Task function operation '${
721 message.taskFunctionOperation as string
722 // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
723 }' failed on worker ${message.workerId} with error: '${
724 // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
725 message.workerError!.message
730 this.deregisterWorkerMessageListener(
731 this.getWorkerNodeKeyByWorkerId(message
.workerId
),
732 taskFunctionOperationListener
736 this.registerWorkerMessageListener(
738 taskFunctionOperationListener
740 this.sendToWorker(workerNodeKey
, message
)
744 private async sendTaskFunctionOperationToWorkers (
745 message
: MessageValue
<Data
>
746 ): Promise
<boolean> {
747 return await new Promise
<boolean>((resolve
, reject
) => {
748 const responsesReceived
= new Array<MessageValue
<Response
>>()
749 const taskFunctionOperationsListener
= (
750 message
: MessageValue
<Response
>
752 this.checkMessageWorkerId(message
)
753 if (message
.taskFunctionOperationStatus
!= null) {
754 responsesReceived
.push(message
)
755 if (responsesReceived
.length
=== this.workerNodes
.length
) {
757 responsesReceived
.every(
758 message
=> message
.taskFunctionOperationStatus
=== true
763 responsesReceived
.some(
764 message
=> message
.taskFunctionOperationStatus
=== false
767 const errorResponse
= responsesReceived
.find(
768 response
=> response
.taskFunctionOperationStatus
=== false
772 `Task function operation '${
773 message.taskFunctionOperation as string
774 // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
775 }' failed on worker ${errorResponse!
776 .workerId!} with error: '${
777 // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
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 if (this.workerNodes
?.[workerNodeKey
] == null) {
1009 const killMessageListener
= (message
: MessageValue
<Response
>): void => {
1010 this.checkMessageWorkerId(message
)
1011 if (message
.kill
=== 'success') {
1013 } else if (message
.kill
=== 'failure') {
1016 // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
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 if (this.workerNodes
[workerNodeKey
]?.usage
!= null) {
1077 const workerUsage
= this.workerNodes
[workerNodeKey
].usage
1078 ++workerUsage
.tasks
.executing
1079 updateWaitTimeWorkerUsage(
1080 this.workerChoiceStrategyContext
,
1086 this.shallUpdateTaskFunctionWorkerUsage(workerNodeKey
) &&
1087 // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
1088 this.workerNodes
[workerNodeKey
].getTaskFunctionWorkerUsage(task
.name
!) !=
1091 // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
1092 const taskFunctionWorkerUsage
= this.workerNodes
[
1094 // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
1095 ].getTaskFunctionWorkerUsage(task
.name
!)!
1096 ++taskFunctionWorkerUsage
.tasks
.executing
1097 updateWaitTimeWorkerUsage(
1098 this.workerChoiceStrategyContext
,
1099 taskFunctionWorkerUsage
,
1106 * Hook executed after the worker task execution.
1107 * Can be overridden.
1109 * @param workerNodeKey - The worker node key.
1110 * @param message - The received message.
1112 protected afterTaskExecutionHook (
1113 workerNodeKey
: number,
1114 message
: MessageValue
<Response
>
1116 let needWorkerChoiceStrategyUpdate
= false
1117 if (this.workerNodes
[workerNodeKey
]?.usage
!= null) {
1118 const workerUsage
= this.workerNodes
[workerNodeKey
].usage
1119 updateTaskStatisticsWorkerUsage(workerUsage
, message
)
1120 updateRunTimeWorkerUsage(
1121 this.workerChoiceStrategyContext
,
1125 updateEluWorkerUsage(
1126 this.workerChoiceStrategyContext
,
1130 needWorkerChoiceStrategyUpdate
= true
1133 this.shallUpdateTaskFunctionWorkerUsage(workerNodeKey
) &&
1134 this.workerNodes
[workerNodeKey
].getTaskFunctionWorkerUsage(
1135 // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
1136 message
.taskPerformance
!.name
1139 // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
1140 const taskFunctionWorkerUsage
= this.workerNodes
[
1142 // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
1143 ].getTaskFunctionWorkerUsage(message
.taskPerformance
!.name
)!
1144 updateTaskStatisticsWorkerUsage(taskFunctionWorkerUsage
, message
)
1145 updateRunTimeWorkerUsage(
1146 this.workerChoiceStrategyContext
,
1147 taskFunctionWorkerUsage
,
1150 updateEluWorkerUsage(
1151 this.workerChoiceStrategyContext
,
1152 taskFunctionWorkerUsage
,
1155 needWorkerChoiceStrategyUpdate
= true
1157 if (needWorkerChoiceStrategyUpdate
) {
1158 this.workerChoiceStrategyContext
.update(workerNodeKey
)
1163 * Whether the worker node shall update its task function worker usage or not.
1165 * @param workerNodeKey - The worker node key.
1166 * @returns `true` if the worker node shall update its task function worker usage, `false` otherwise.
1168 private shallUpdateTaskFunctionWorkerUsage (workerNodeKey
: number): boolean {
1169 const workerInfo
= this.getWorkerInfo(workerNodeKey
)
1171 workerInfo
!= null &&
1172 Array.isArray(workerInfo
.taskFunctionNames
) &&
1173 workerInfo
.taskFunctionNames
.length
> 2
1178 * Chooses a worker node for the next task.
1180 * The default worker choice strategy uses a round robin algorithm to distribute the tasks.
1182 * @returns The chosen worker node key
1184 private chooseWorkerNode (): number {
1185 if (this.shallCreateDynamicWorker()) {
1186 const workerNodeKey
= this.createAndSetupDynamicWorkerNode()
1188 this.workerChoiceStrategyContext
.getStrategyPolicy().dynamicWorkerUsage
1190 return workerNodeKey
1193 return this.workerChoiceStrategyContext
.execute()
1197 * Conditions for dynamic worker creation.
1199 * @returns Whether to create a dynamic worker or not.
1201 protected abstract shallCreateDynamicWorker (): boolean
1204 * Sends a message to worker given its worker node key.
1206 * @param workerNodeKey - The worker node key.
1207 * @param message - The message.
1208 * @param transferList - The optional array of transferable objects.
1210 protected abstract sendToWorker (
1211 workerNodeKey
: number,
1212 message
: MessageValue
<Data
>,
1213 transferList
?: TransferListItem
[]
1217 * Creates a new, completely set up worker node.
1219 * @returns New, completely set up worker node key.
1221 protected createAndSetupWorkerNode (): number {
1222 const workerNode
= this.createWorkerNode()
1223 workerNode
.registerWorkerEventHandler(
1225 this.opts
.onlineHandler
?? EMPTY_FUNCTION
1227 workerNode
.registerWorkerEventHandler(
1229 this.opts
.messageHandler
?? EMPTY_FUNCTION
1231 workerNode
.registerWorkerEventHandler(
1233 this.opts
.errorHandler
?? EMPTY_FUNCTION
1235 workerNode
.registerWorkerEventHandler('error', (error
: Error) => {
1236 workerNode
.info
.ready
= false
1237 this.emitter
?.emit(PoolEvents
.error
, error
)
1241 this.opts
.restartWorkerOnError
=== true
1243 if (workerNode
.info
.dynamic
) {
1244 this.createAndSetupDynamicWorkerNode()
1246 this.createAndSetupWorkerNode()
1252 this.opts
.enableTasksQueue
=== true
1254 this.redistributeQueuedTasks(this.workerNodes
.indexOf(workerNode
))
1256 workerNode
?.terminate().catch(error
=> {
1257 this.emitter
?.emit(PoolEvents
.error
, error
)
1260 workerNode
.registerWorkerEventHandler(
1262 this.opts
.exitHandler
?? EMPTY_FUNCTION
1264 workerNode
.registerOnceWorkerEventHandler('exit', () => {
1265 this.removeWorkerNode(workerNode
)
1267 const workerNodeKey
= this.addWorkerNode(workerNode
)
1268 this.afterWorkerNodeSetup(workerNodeKey
)
1269 return workerNodeKey
1273 * Creates a new, completely set up dynamic worker node.
1275 * @returns New, completely set up dynamic worker node key.
1277 protected createAndSetupDynamicWorkerNode (): number {
1278 const workerNodeKey
= this.createAndSetupWorkerNode()
1279 this.registerWorkerMessageListener(workerNodeKey
, message
=> {
1280 this.checkMessageWorkerId(message
)
1281 const localWorkerNodeKey
= this.getWorkerNodeKeyByWorkerId(
1284 const workerUsage
= this.workerNodes
[localWorkerNodeKey
].usage
1285 // Kill message received from worker
1287 isKillBehavior(KillBehaviors
.HARD
, message
.kill
) ||
1288 (isKillBehavior(KillBehaviors
.SOFT
, message
.kill
) &&
1289 ((this.opts
.enableTasksQueue
=== false &&
1290 workerUsage
.tasks
.executing
=== 0) ||
1291 (this.opts
.enableTasksQueue
=== true &&
1292 workerUsage
.tasks
.executing
=== 0 &&
1293 this.tasksQueueSize(localWorkerNodeKey
) === 0)))
1295 // Flag the worker node as not ready immediately
1296 this.flagWorkerNodeAsNotReady(localWorkerNodeKey
)
1297 this.destroyWorkerNode(localWorkerNodeKey
).catch(error
=> {
1298 this.emitter
?.emit(PoolEvents
.error
, error
)
1302 const workerInfo
= this.getWorkerInfo(workerNodeKey
)
1303 this.sendToWorker(workerNodeKey
, {
1306 if (this.taskFunctions
.size
> 0) {
1307 for (const [taskFunctionName
, taskFunction
] of this.taskFunctions
) {
1308 this.sendTaskFunctionOperationToWorker(workerNodeKey
, {
1309 taskFunctionOperation
: 'add',
1311 taskFunction
: taskFunction
.toString()
1313 this.emitter
?.emit(PoolEvents
.error
, error
)
1317 workerInfo
.dynamic
= true
1319 this.workerChoiceStrategyContext
.getStrategyPolicy().dynamicWorkerReady
||
1320 this.workerChoiceStrategyContext
.getStrategyPolicy().dynamicWorkerUsage
1322 workerInfo
.ready
= true
1324 this.checkAndEmitDynamicWorkerCreationEvents()
1325 return workerNodeKey
1329 * Registers a listener callback on the worker given its worker node key.
1331 * @param workerNodeKey - The worker node key.
1332 * @param listener - The message listener callback.
1334 protected abstract registerWorkerMessageListener
<
1335 Message
extends Data
| Response
1337 workerNodeKey
: number,
1338 listener
: (message
: MessageValue
<Message
>) => void
1342 * Registers once a listener callback on the worker given its worker node key.
1344 * @param workerNodeKey - The worker node key.
1345 * @param listener - The message listener callback.
1347 protected abstract registerOnceWorkerMessageListener
<
1348 Message
extends Data
| Response
1350 workerNodeKey
: number,
1351 listener
: (message
: MessageValue
<Message
>) => void
1355 * Deregisters a listener callback on the worker given its worker node key.
1357 * @param workerNodeKey - The worker node key.
1358 * @param listener - The message listener callback.
1360 protected abstract deregisterWorkerMessageListener
<
1361 Message
extends Data
| Response
1363 workerNodeKey
: number,
1364 listener
: (message
: MessageValue
<Message
>) => void
1368 * Method hooked up after a worker node has been newly created.
1369 * Can be overridden.
1371 * @param workerNodeKey - The newly created worker node key.
1373 protected afterWorkerNodeSetup (workerNodeKey
: number): void {
1374 // Listen to worker messages.
1375 this.registerWorkerMessageListener(
1377 this.workerMessageListener
1379 // Send the startup message to worker.
1380 this.sendStartupMessageToWorker(workerNodeKey
)
1381 // Send the statistics message to worker.
1382 this.sendStatisticsMessageToWorker(workerNodeKey
)
1383 if (this.opts
.enableTasksQueue
=== true) {
1384 if (this.opts
.tasksQueueOptions
?.taskStealing
=== true) {
1385 this.workerNodes
[workerNodeKey
].on(
1387 this.handleIdleWorkerNodeEvent
1390 if (this.opts
.tasksQueueOptions
?.tasksStealingOnBackPressure
=== true) {
1391 this.workerNodes
[workerNodeKey
].on(
1393 this.handleBackPressureEvent
1400 * Sends the startup message to worker given its worker node key.
1402 * @param workerNodeKey - The worker node key.
1404 protected abstract sendStartupMessageToWorker (workerNodeKey
: number): void
1407 * Sends the statistics message to worker given its worker node key.
1409 * @param workerNodeKey - The worker node key.
1411 private sendStatisticsMessageToWorker (workerNodeKey
: number): void {
1412 this.sendToWorker(workerNodeKey
, {
1415 this.workerChoiceStrategyContext
.getTaskStatisticsRequirements()
1417 elu
: this.workerChoiceStrategyContext
.getTaskStatisticsRequirements()
1423 private cannotStealTask (): boolean {
1424 return this.workerNodes
.length
<= 1 || this.info
.queuedTasks
=== 0
1427 private handleTask (workerNodeKey
: number, task
: Task
<Data
>): void {
1428 if (this.shallExecuteTask(workerNodeKey
)) {
1429 this.executeTask(workerNodeKey
, task
)
1431 this.enqueueTask(workerNodeKey
, task
)
1435 private redistributeQueuedTasks (workerNodeKey
: number): void {
1436 if (workerNodeKey
=== -1 || this.cannotStealTask()) {
1439 while (this.tasksQueueSize(workerNodeKey
) > 0) {
1440 const destinationWorkerNodeKey
= this.workerNodes
.reduce(
1441 (minWorkerNodeKey
, workerNode
, workerNodeKey
, workerNodes
) => {
1442 return workerNode
.info
.ready
&&
1443 workerNode
.usage
.tasks
.queued
<
1444 workerNodes
[minWorkerNodeKey
].usage
.tasks
.queued
1451 destinationWorkerNodeKey
,
1452 // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
1453 this.dequeueTask(workerNodeKey
)!
1458 private updateTaskStolenStatisticsWorkerUsage (
1459 workerNodeKey
: number,
1462 const workerNode
= this.workerNodes
[workerNodeKey
]
1463 if (workerNode
?.usage
!= null) {
1464 ++workerNode
.usage
.tasks
.stolen
1467 this.shallUpdateTaskFunctionWorkerUsage(workerNodeKey
) &&
1468 workerNode
.getTaskFunctionWorkerUsage(taskName
) != null
1470 const taskFunctionWorkerUsage
=
1471 // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
1472 workerNode
.getTaskFunctionWorkerUsage(taskName
)!
1473 ++taskFunctionWorkerUsage
.tasks
.stolen
1477 private updateTaskSequentiallyStolenStatisticsWorkerUsage (
1478 workerNodeKey
: number
1480 const workerNode
= this.workerNodes
[workerNodeKey
]
1481 if (workerNode
?.usage
!= null) {
1482 ++workerNode
.usage
.tasks
.sequentiallyStolen
1486 private updateTaskSequentiallyStolenStatisticsTaskFunctionWorkerUsage (
1487 workerNodeKey
: number,
1490 const workerNode
= this.workerNodes
[workerNodeKey
]
1492 this.shallUpdateTaskFunctionWorkerUsage(workerNodeKey
) &&
1493 workerNode
.getTaskFunctionWorkerUsage(taskName
) != null
1495 const taskFunctionWorkerUsage
=
1496 // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
1497 workerNode
.getTaskFunctionWorkerUsage(taskName
)!
1498 ++taskFunctionWorkerUsage
.tasks
.sequentiallyStolen
1502 private resetTaskSequentiallyStolenStatisticsWorkerUsage (
1503 workerNodeKey
: number
1505 const workerNode
= this.workerNodes
[workerNodeKey
]
1506 if (workerNode
?.usage
!= null) {
1507 workerNode
.usage
.tasks
.sequentiallyStolen
= 0
1511 private resetTaskSequentiallyStolenStatisticsTaskFunctionWorkerUsage (
1512 workerNodeKey
: number,
1515 const workerNode
= this.workerNodes
[workerNodeKey
]
1517 this.shallUpdateTaskFunctionWorkerUsage(workerNodeKey
) &&
1518 workerNode
.getTaskFunctionWorkerUsage(taskName
) != null
1520 const taskFunctionWorkerUsage
=
1521 // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
1522 workerNode
.getTaskFunctionWorkerUsage(taskName
)!
1523 taskFunctionWorkerUsage
.tasks
.sequentiallyStolen
= 0
1527 private readonly handleIdleWorkerNodeEvent
= (
1528 eventDetail
: WorkerNodeEventDetail
,
1529 previousStolenTask
?: Task
<Data
>
1531 const { workerNodeKey
} = eventDetail
1532 if (workerNodeKey
== null) {
1534 'WorkerNode event detail workerNodeKey property must be defined'
1538 this.cannotStealTask() ||
1539 // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
1540 this.info
.stealingWorkerNodes
! > Math.floor(this.workerNodes
.length
/ 2)
1542 if (previousStolenTask
!= null) {
1543 this.getWorkerInfo(workerNodeKey
).stealing
= false
1547 const workerNodeTasksUsage
= this.workerNodes
[workerNodeKey
].usage
.tasks
1549 previousStolenTask
!= null &&
1550 workerNodeTasksUsage
.sequentiallyStolen
> 0 &&
1551 (workerNodeTasksUsage
.executing
> 0 ||
1552 this.tasksQueueSize(workerNodeKey
) > 0)
1554 this.getWorkerInfo(workerNodeKey
).stealing
= false
1555 // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
1556 for (const taskName
of this.workerNodes
[workerNodeKey
].info
1557 .taskFunctionNames
!) {
1558 this.resetTaskSequentiallyStolenStatisticsTaskFunctionWorkerUsage(
1563 this.resetTaskSequentiallyStolenStatisticsWorkerUsage(workerNodeKey
)
1566 this.getWorkerInfo(workerNodeKey
).stealing
= true
1567 const stolenTask
= this.workerNodeStealTask(workerNodeKey
)
1569 this.shallUpdateTaskFunctionWorkerUsage(workerNodeKey
) &&
1572 // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
1573 const taskFunctionTasksWorkerUsage
= this.workerNodes
[
1575 // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
1576 ].getTaskFunctionWorkerUsage(stolenTask
.name
!)!.tasks
1578 taskFunctionTasksWorkerUsage
.sequentiallyStolen
=== 0 ||
1579 (previousStolenTask
!= null &&
1580 previousStolenTask
.name
=== stolenTask
.name
&&
1581 taskFunctionTasksWorkerUsage
.sequentiallyStolen
> 0)
1583 this.updateTaskSequentiallyStolenStatisticsTaskFunctionWorkerUsage(
1585 // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
1589 this.resetTaskSequentiallyStolenStatisticsTaskFunctionWorkerUsage(
1591 // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
1596 sleep(exponentialDelay(workerNodeTasksUsage
.sequentiallyStolen
))
1598 this.handleIdleWorkerNodeEvent(eventDetail
, stolenTask
)
1601 .catch(EMPTY_FUNCTION
)
1604 private readonly workerNodeStealTask
= (
1605 workerNodeKey
: number
1606 ): Task
<Data
> | undefined => {
1607 const workerNodes
= this.workerNodes
1610 (workerNodeA
, workerNodeB
) =>
1611 workerNodeB
.usage
.tasks
.queued
- workerNodeA
.usage
.tasks
.queued
1613 const sourceWorkerNode
= workerNodes
.find(
1614 (sourceWorkerNode
, sourceWorkerNodeKey
) =>
1615 sourceWorkerNode
.info
.ready
&&
1616 !sourceWorkerNode
.info
.stealing
&&
1617 sourceWorkerNodeKey
!== workerNodeKey
&&
1618 sourceWorkerNode
.usage
.tasks
.queued
> 0
1620 if (sourceWorkerNode
!= null) {
1621 // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
1622 const task
= sourceWorkerNode
.popTask()!
1623 this.handleTask(workerNodeKey
, task
)
1624 this.updateTaskSequentiallyStolenStatisticsWorkerUsage(workerNodeKey
)
1625 // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
1626 this.updateTaskStolenStatisticsWorkerUsage(workerNodeKey
, task
.name
!)
1631 private readonly handleBackPressureEvent
= (
1632 eventDetail
: WorkerNodeEventDetail
1635 this.cannotStealTask() ||
1636 // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
1637 this.info
.stealingWorkerNodes
! > Math.floor(this.workerNodes
.length
/ 2)
1641 const { workerId
} = eventDetail
1642 const sizeOffset
= 1
1643 // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
1644 if (this.opts
.tasksQueueOptions
!.size
! <= sizeOffset
) {
1647 const sourceWorkerNode
=
1648 this.workerNodes
[this.getWorkerNodeKeyByWorkerId(workerId
)]
1649 const workerNodes
= this.workerNodes
1652 (workerNodeA
, workerNodeB
) =>
1653 workerNodeA
.usage
.tasks
.queued
- workerNodeB
.usage
.tasks
.queued
1655 for (const [workerNodeKey
, workerNode
] of workerNodes
.entries()) {
1657 sourceWorkerNode
.usage
.tasks
.queued
> 0 &&
1658 workerNode
.info
.ready
&&
1659 !workerNode
.info
.stealing
&&
1660 workerNode
.info
.id
!== workerId
&&
1661 workerNode
.usage
.tasks
.queued
<
1662 // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
1663 this.opts
.tasksQueueOptions
!.size
! - sizeOffset
1665 this.getWorkerInfo(workerNodeKey
).stealing
= true
1666 // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
1667 const task
= sourceWorkerNode
.popTask()!
1668 this.handleTask(workerNodeKey
, task
)
1669 // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
1670 this.updateTaskStolenStatisticsWorkerUsage(workerNodeKey
, task
.name
!)
1671 this.getWorkerInfo(workerNodeKey
).stealing
= false
1677 * This method is the message listener registered on each worker.
1679 protected readonly workerMessageListener
= (
1680 message
: MessageValue
<Response
>
1682 this.checkMessageWorkerId(message
)
1683 const { workerId
, ready
, taskId
, taskFunctionNames
} = message
1684 if (ready
!= null && taskFunctionNames
!= null) {
1685 // Worker ready response received from worker
1686 this.handleWorkerReadyResponse(message
)
1687 } else if (taskId
!= null) {
1688 // Task execution response received from worker
1689 this.handleTaskExecutionResponse(message
)
1690 } else if (taskFunctionNames
!= null) {
1691 // Task function names message received from worker
1693 this.getWorkerNodeKeyByWorkerId(workerId
)
1694 ).taskFunctionNames
= taskFunctionNames
1698 private handleWorkerReadyResponse (message
: MessageValue
<Response
>): void {
1699 const { workerId
, ready
, taskFunctionNames
} = message
1700 if (ready
=== false) {
1701 // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
1702 throw new Error(`Worker ${workerId!} failed to initialize`)
1704 const workerInfo
= this.getWorkerInfo(
1705 this.getWorkerNodeKeyByWorkerId(workerId
)
1707 workerInfo
.ready
= ready
as boolean
1708 workerInfo
.taskFunctionNames
= taskFunctionNames
1709 if (!this.readyEventEmitted
&& this.ready
) {
1710 this.readyEventEmitted
= true
1711 this.emitter
?.emit(PoolEvents
.ready
, this.info
)
1715 private handleTaskExecutionResponse (message
: MessageValue
<Response
>): void {
1716 const { workerId
, taskId
, workerError
, data
} = message
1717 // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
1718 const promiseResponse
= this.promiseResponseMap
.get(taskId
!)
1719 if (promiseResponse
!= null) {
1720 const { resolve
, reject
, workerNodeKey
, asyncResource
} = promiseResponse
1721 const workerNode
= this.workerNodes
[workerNodeKey
]
1722 if (workerError
!= null) {
1723 this.emitter
?.emit(PoolEvents
.taskError
, workerError
)
1724 asyncResource
!= null
1725 ? asyncResource
.runInAsyncScope(
1730 : reject(workerError
.message
)
1732 asyncResource
!= null
1733 ? asyncResource
.runInAsyncScope(resolve
, this.emitter
, data
)
1734 : resolve(data
as Response
)
1736 asyncResource
?.emitDestroy()
1737 this.afterTaskExecutionHook(workerNodeKey
, message
)
1738 // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
1739 this.promiseResponseMap
.delete(taskId
!)
1740 workerNode
?.emit('taskFinished', taskId
)
1741 if (this.opts
.enableTasksQueue
=== true && !this.destroying
) {
1742 const workerNodeTasksUsage
= workerNode
.usage
.tasks
1744 this.tasksQueueSize(workerNodeKey
) > 0 &&
1745 workerNodeTasksUsage
.executing
<
1746 // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
1747 this.opts
.tasksQueueOptions
!.concurrency
!
1749 // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
1750 this.executeTask(workerNodeKey
, this.dequeueTask(workerNodeKey
)!)
1753 workerNodeTasksUsage
.executing
=== 0 &&
1754 this.tasksQueueSize(workerNodeKey
) === 0 &&
1755 workerNodeTasksUsage
.sequentiallyStolen
=== 0
1757 workerNode
.emit('idleWorkerNode', {
1758 // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
1759 workerId
: workerId
!,
1767 private checkAndEmitTaskExecutionEvents (): void {
1769 this.emitter
?.emit(PoolEvents
.busy
, this.info
)
1773 private checkAndEmitTaskQueuingEvents (): void {
1774 if (this.hasBackPressure()) {
1775 this.emitter
?.emit(PoolEvents
.backPressure
, this.info
)
1780 * Emits dynamic worker creation events.
1782 protected abstract checkAndEmitDynamicWorkerCreationEvents (): void
1785 * Gets the worker information given its worker node key.
1787 * @param workerNodeKey - The worker node key.
1788 * @returns The worker information.
1790 protected getWorkerInfo (workerNodeKey
: number): WorkerInfo
{
1791 return this.workerNodes
[workerNodeKey
]?.info
1795 * Creates a worker node.
1797 * @returns The created worker node.
1799 private createWorkerNode (): IWorkerNode
<Worker
, Data
> {
1800 const workerNode
= new WorkerNode
<Worker
, Data
>(
1805 workerOptions
: this.opts
.workerOptions
,
1806 tasksQueueBackPressureSize
:
1807 this.opts
.tasksQueueOptions
?.size
??
1808 getDefaultTasksQueueOptions(
1809 this.maximumNumberOfWorkers
?? this.minimumNumberOfWorkers
1813 // Flag the worker node as ready at pool startup.
1814 if (this.starting
) {
1815 workerNode
.info
.ready
= true
1821 * Adds the given worker node in the pool worker nodes.
1823 * @param workerNode - The worker node.
1824 * @returns The added worker node key.
1825 * @throws {@link https://nodejs.org/api/errors.html#class-error} If the added worker node is not found.
1827 private addWorkerNode (workerNode
: IWorkerNode
<Worker
, Data
>): number {
1828 this.workerNodes
.push(workerNode
)
1829 const workerNodeKey
= this.workerNodes
.indexOf(workerNode
)
1830 if (workerNodeKey
=== -1) {
1831 throw new Error('Worker added not found in worker nodes')
1833 return workerNodeKey
1837 * Removes the worker node from the pool worker nodes.
1839 * @param workerNode - The worker node.
1841 private removeWorkerNode (workerNode
: IWorkerNode
<Worker
, Data
>): void {
1842 const workerNodeKey
= this.workerNodes
.indexOf(workerNode
)
1843 if (workerNodeKey
!== -1) {
1844 this.workerNodes
.splice(workerNodeKey
, 1)
1845 this.workerChoiceStrategyContext
.remove(workerNodeKey
)
1849 protected flagWorkerNodeAsNotReady (workerNodeKey
: number): void {
1850 this.getWorkerInfo(workerNodeKey
).ready
= false
1854 public hasWorkerNodeBackPressure (workerNodeKey
: number): boolean {
1856 this.opts
.enableTasksQueue
=== true &&
1857 this.workerNodes
[workerNodeKey
].hasBackPressure()
1861 private hasBackPressure (): boolean {
1863 this.opts
.enableTasksQueue
=== true &&
1864 this.workerNodes
.findIndex(
1865 workerNode
=> !workerNode
.hasBackPressure()
1871 * Executes the given task on the worker given its worker node key.
1873 * @param workerNodeKey - The worker node key.
1874 * @param task - The task to execute.
1876 private executeTask (workerNodeKey
: number, task
: Task
<Data
>): void {
1877 this.beforeTaskExecutionHook(workerNodeKey
, task
)
1878 this.sendToWorker(workerNodeKey
, task
, task
.transferList
)
1879 this.checkAndEmitTaskExecutionEvents()
1882 private enqueueTask (workerNodeKey
: number, task
: Task
<Data
>): number {
1883 const tasksQueueSize
= this.workerNodes
[workerNodeKey
].enqueueTask(task
)
1884 this.checkAndEmitTaskQueuingEvents()
1885 return tasksQueueSize
1888 private dequeueTask (workerNodeKey
: number): Task
<Data
> | undefined {
1889 return this.workerNodes
[workerNodeKey
].dequeueTask()
1892 private tasksQueueSize (workerNodeKey
: number): number {
1893 return this.workerNodes
[workerNodeKey
].tasksQueueSize()
1896 protected flushTasksQueue (workerNodeKey
: number): number {
1897 let flushedTasks
= 0
1898 while (this.tasksQueueSize(workerNodeKey
) > 0) {
1899 // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
1900 this.executeTask(workerNodeKey
, this.dequeueTask(workerNodeKey
)!)
1903 this.workerNodes
[workerNodeKey
].clearTasksQueue()
1907 private flushTasksQueues (): void {
1908 for (const [workerNodeKey
] of this.workerNodes
.entries()) {
1909 this.flushTasksQueue(workerNodeKey
)