1 import { AsyncResource
} from
'node:async_hooks'
2 import { randomUUID
} from
'node:crypto'
3 import { EventEmitterAsyncResource
} from
'node:events'
4 import { performance
} from
'node:perf_hooks'
5 import type { TransferListItem
} from
'node:worker_threads'
7 import { defaultBucketSize
} from
'../priority-queue.js'
10 PromiseResponseWrapper
,
12 TaskFunctionProperties
,
13 } from
'../utility-types.js'
16 buildTaskFunctionProperties
,
31 } from
'../worker/task-functions.js'
32 import { KillBehaviors
} from
'../worker/worker-options.js'
40 type TasksQueueOptions
,
44 WorkerChoiceStrategies
,
45 type WorkerChoiceStrategy
,
46 type WorkerChoiceStrategyOptions
,
47 } from
'./selection-strategies/selection-strategies-types.js'
48 import { WorkerChoiceStrategiesContext
} from
'./selection-strategies/worker-choice-strategies-context.js'
52 checkValidTasksQueueOptions
,
53 checkValidWorkerChoiceStrategy
,
54 getDefaultTasksQueueOptions
,
56 updateRunTimeWorkerUsage
,
57 updateTaskStatisticsWorkerUsage
,
58 updateWaitTimeWorkerUsage
,
61 import { version
} from
'./version.js'
66 WorkerNodeEventDetail
,
69 import { WorkerNode
} from
'./worker-node.js'
72 * Base class that implements some shared logic for all poolifier pools.
73 * @typeParam Worker - Type of worker which manages this pool.
74 * @typeParam Data - Type of data sent to the worker. This can only be structured-cloneable data.
75 * @typeParam Response - Type of execution response. This can only be structured-cloneable data.
77 export abstract class AbstractPool
<
78 Worker
extends IWorker
,
81 > implements IPool
<Worker
, Data
, Response
> {
83 public readonly workerNodes
: IWorkerNode
<Worker
, Data
>[] = []
86 public emitter
?: EventEmitterAsyncResource
89 * The task execution response promise map:
90 * - `key`: The message id of each submitted task.
91 * - `value`: An object that contains task's worker node key, execution response promise resolve and reject callbacks, async resource.
93 * When we receive a message from the worker, we get a map entry with the promise resolve/reject bound to the message id.
95 protected promiseResponseMap
: Map
<
96 `${string}-${string}-${string}-${string}-${string}`,
97 PromiseResponseWrapper
<Response
>
99 `${string}-${string}-${string}-${string}-${string}`,
100 PromiseResponseWrapper
<Response
>
104 * Worker choice strategies context referencing worker choice algorithms implementation.
106 protected workerChoiceStrategiesContext
?: WorkerChoiceStrategiesContext
<
113 * The task functions added at runtime map:
114 * - `key`: The task function name.
115 * - `value`: The task function object.
117 private readonly taskFunctions
: Map
<
119 TaskFunctionObject
<Data
, Response
>
123 * Whether the pool is started or not.
125 private started
: boolean
127 * Whether the pool is starting or not.
129 private starting
: boolean
131 * Whether the pool is destroying or not.
133 private destroying
: boolean
135 * Whether the minimum number of workers is starting or not.
137 private startingMinimumNumberOfWorkers
: boolean
139 * Whether the pool ready event has been emitted or not.
141 private readyEventEmitted
: boolean
143 * The start timestamp of the pool.
145 private startTimestamp
?: number
148 * Constructs a new poolifier pool.
149 * @param minimumNumberOfWorkers - Minimum number of workers that this pool manages.
150 * @param filePath - Path to the worker file.
151 * @param opts - Options for the pool.
152 * @param maximumNumberOfWorkers - Maximum number of workers that this pool manages.
155 protected readonly minimumNumberOfWorkers
: number,
156 protected readonly filePath
: string,
157 protected readonly opts
: PoolOptions
<Worker
>,
158 protected readonly maximumNumberOfWorkers
?: number
160 if (!this.isMain()) {
162 'Cannot start a pool from a worker with the same type as the pool'
166 checkFilePath(this.filePath
)
167 this.checkMinimumNumberOfWorkers(this.minimumNumberOfWorkers
)
168 this.checkPoolOptions(this.opts
)
170 this.chooseWorkerNode
= this.chooseWorkerNode
.bind(this)
171 this.executeTask
= this.executeTask
.bind(this)
172 this.enqueueTask
= this.enqueueTask
.bind(this)
174 if (this.opts
.enableEvents
=== true) {
175 this.initEventEmitter()
177 this.workerChoiceStrategiesContext
= new WorkerChoiceStrategiesContext
<
183 // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
184 [this.opts
.workerChoiceStrategy
!],
185 this.opts
.workerChoiceStrategyOptions
190 this.taskFunctions
= new Map
<string, TaskFunctionObject
<Data
, Response
>>()
193 this.starting
= false
194 this.destroying
= false
195 this.readyEventEmitted
= false
196 this.startingMinimumNumberOfWorkers
= false
197 if (this.opts
.startWorkers
=== true) {
202 private checkPoolType (): void {
203 if (this.type === PoolTypes
.fixed
&& this.maximumNumberOfWorkers
!= null) {
205 'Cannot instantiate a fixed pool with a maximum number of workers specified at initialization'
210 private checkMinimumNumberOfWorkers (
211 minimumNumberOfWorkers
: number | undefined
213 if (minimumNumberOfWorkers
== null) {
215 'Cannot instantiate a pool without specifying the number of workers'
217 } else if (!Number.isSafeInteger(minimumNumberOfWorkers
)) {
219 'Cannot instantiate a pool with a non safe integer number of workers'
221 } else if (minimumNumberOfWorkers
< 0) {
222 throw new RangeError(
223 'Cannot instantiate a pool with a negative number of workers'
225 } else if (this.type === PoolTypes
.fixed
&& minimumNumberOfWorkers
=== 0) {
226 throw new RangeError('Cannot instantiate a fixed pool with zero worker')
230 private checkPoolOptions (opts
: PoolOptions
<Worker
>): void {
231 if (isPlainObject(opts
)) {
232 this.opts
.startWorkers
= opts
.startWorkers
?? true
233 checkValidWorkerChoiceStrategy(opts
.workerChoiceStrategy
)
234 this.opts
.workerChoiceStrategy
=
235 opts
.workerChoiceStrategy
?? WorkerChoiceStrategies
.ROUND_ROBIN
236 this.checkValidWorkerChoiceStrategyOptions(
237 opts
.workerChoiceStrategyOptions
239 if (opts
.workerChoiceStrategyOptions
!= null) {
240 this.opts
.workerChoiceStrategyOptions
= opts
.workerChoiceStrategyOptions
242 this.opts
.restartWorkerOnError
= opts
.restartWorkerOnError
?? true
243 this.opts
.enableEvents
= opts
.enableEvents
?? true
244 this.opts
.enableTasksQueue
= opts
.enableTasksQueue
?? false
245 if (this.opts
.enableTasksQueue
) {
246 checkValidTasksQueueOptions(opts
.tasksQueueOptions
)
247 this.opts
.tasksQueueOptions
= this.buildTasksQueueOptions(
248 opts
.tasksQueueOptions
252 throw new TypeError('Invalid pool options: must be a plain object')
256 private checkValidWorkerChoiceStrategyOptions (
257 workerChoiceStrategyOptions
: WorkerChoiceStrategyOptions
| undefined
260 workerChoiceStrategyOptions
!= null &&
261 !isPlainObject(workerChoiceStrategyOptions
)
264 'Invalid worker choice strategy options: must be a plain object'
268 workerChoiceStrategyOptions
?.weights
!= null &&
269 Object.keys(workerChoiceStrategyOptions
.weights
).length
!==
270 (this.maximumNumberOfWorkers
?? this.minimumNumberOfWorkers
)
273 'Invalid worker choice strategy options: must have a weight for each worker node'
277 workerChoiceStrategyOptions
?.measurement
!= null &&
278 !Object.values(Measurements
).includes(
279 workerChoiceStrategyOptions
.measurement
283 `Invalid worker choice strategy options: invalid measurement '${workerChoiceStrategyOptions.measurement}'`
288 private initEventEmitter (): void {
289 this.emitter
= new EventEmitterAsyncResource({
290 name
: `poolifier:${this.type}-${this.worker}-pool`,
295 public get
info (): PoolInfo
{
300 started
: this.started
,
302 // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
303 defaultStrategy
: this.opts
.workerChoiceStrategy
!,
304 strategyRetries
: this.workerChoiceStrategiesContext
?.retriesCount
?? 0,
305 minSize
: this.minimumNumberOfWorkers
,
306 maxSize
: this.maximumNumberOfWorkers
?? this.minimumNumberOfWorkers
,
307 ...(this.workerChoiceStrategiesContext
?.getTaskStatisticsRequirements()
308 .runTime
.aggregate
=== true &&
309 this.workerChoiceStrategiesContext
.getTaskStatisticsRequirements()
310 .waitTime
.aggregate
&& {
311 utilization
: round(this.utilization
),
313 workerNodes
: this.workerNodes
.length
,
314 idleWorkerNodes
: this.workerNodes
.reduce(
315 (accumulator
, workerNode
) =>
316 workerNode
.usage
.tasks
.executing
=== 0
321 ...(this.opts
.enableTasksQueue
=== true && {
322 stealingWorkerNodes
: this.workerNodes
.reduce(
323 (accumulator
, workerNode
) =>
324 workerNode
.info
.stealing
? accumulator
+ 1 : accumulator
,
328 busyWorkerNodes
: this.workerNodes
.reduce(
329 (accumulator
, _
, workerNodeKey
) =>
330 this.isWorkerNodeBusy(workerNodeKey
) ? accumulator
+ 1 : accumulator
,
333 executedTasks
: this.workerNodes
.reduce(
334 (accumulator
, workerNode
) =>
335 accumulator
+ workerNode
.usage
.tasks
.executed
,
338 executingTasks
: this.workerNodes
.reduce(
339 (accumulator
, workerNode
) =>
340 accumulator
+ workerNode
.usage
.tasks
.executing
,
343 ...(this.opts
.enableTasksQueue
=== true && {
344 queuedTasks
: this.workerNodes
.reduce(
345 (accumulator
, workerNode
) =>
346 accumulator
+ workerNode
.usage
.tasks
.queued
,
350 ...(this.opts
.enableTasksQueue
=== true && {
351 maxQueuedTasks
: this.workerNodes
.reduce(
352 (accumulator
, workerNode
) =>
353 accumulator
+ (workerNode
.usage
.tasks
.maxQueued
?? 0),
357 ...(this.opts
.enableTasksQueue
=== true && {
358 backPressure
: this.hasBackPressure(),
360 ...(this.opts
.enableTasksQueue
=== true && {
361 stolenTasks
: this.workerNodes
.reduce(
362 (accumulator
, workerNode
) =>
363 accumulator
+ workerNode
.usage
.tasks
.stolen
,
367 failedTasks
: this.workerNodes
.reduce(
368 (accumulator
, workerNode
) =>
369 accumulator
+ workerNode
.usage
.tasks
.failed
,
372 ...(this.workerChoiceStrategiesContext
?.getTaskStatisticsRequirements()
373 .runTime
.aggregate
=== true && {
377 ...this.workerNodes
.map(
379 workerNode
.usage
.runTime
.minimum
?? Number.POSITIVE_INFINITY
385 ...this.workerNodes
.map(
387 workerNode
.usage
.runTime
.maximum
?? Number.NEGATIVE_INFINITY
391 ...(this.workerChoiceStrategiesContext
.getTaskStatisticsRequirements()
392 .runTime
.average
&& {
395 this.workerNodes
.reduce
<number[]>(
396 (accumulator
, workerNode
) =>
398 workerNode
.usage
.runTime
.history
.toArray()
405 ...(this.workerChoiceStrategiesContext
.getTaskStatisticsRequirements()
409 this.workerNodes
.reduce
<number[]>(
410 (accumulator
, workerNode
) =>
412 workerNode
.usage
.runTime
.history
.toArray()
421 ...(this.workerChoiceStrategiesContext
?.getTaskStatisticsRequirements()
422 .waitTime
.aggregate
=== true && {
426 ...this.workerNodes
.map(
428 workerNode
.usage
.waitTime
.minimum
?? Number.POSITIVE_INFINITY
434 ...this.workerNodes
.map(
436 workerNode
.usage
.waitTime
.maximum
?? Number.NEGATIVE_INFINITY
440 ...(this.workerChoiceStrategiesContext
.getTaskStatisticsRequirements()
441 .waitTime
.average
&& {
444 this.workerNodes
.reduce
<number[]>(
445 (accumulator
, workerNode
) =>
447 workerNode
.usage
.waitTime
.history
.toArray()
454 ...(this.workerChoiceStrategiesContext
.getTaskStatisticsRequirements()
455 .waitTime
.median
&& {
458 this.workerNodes
.reduce
<number[]>(
459 (accumulator
, workerNode
) =>
461 workerNode
.usage
.waitTime
.history
.toArray()
470 ...(this.workerChoiceStrategiesContext
?.getTaskStatisticsRequirements()
471 .elu
.aggregate
=== true && {
476 ...this.workerNodes
.map(
478 workerNode
.usage
.elu
.idle
.minimum
??
479 Number.POSITIVE_INFINITY
485 ...this.workerNodes
.map(
487 workerNode
.usage
.elu
.idle
.maximum
??
488 Number.NEGATIVE_INFINITY
492 ...(this.workerChoiceStrategiesContext
.getTaskStatisticsRequirements()
496 this.workerNodes
.reduce
<number[]>(
497 (accumulator
, workerNode
) =>
499 workerNode
.usage
.elu
.idle
.history
.toArray()
506 ...(this.workerChoiceStrategiesContext
.getTaskStatisticsRequirements()
510 this.workerNodes
.reduce
<number[]>(
511 (accumulator
, workerNode
) =>
513 workerNode
.usage
.elu
.idle
.history
.toArray()
524 ...this.workerNodes
.map(
526 workerNode
.usage
.elu
.active
.minimum
??
527 Number.POSITIVE_INFINITY
533 ...this.workerNodes
.map(
535 workerNode
.usage
.elu
.active
.maximum
??
536 Number.NEGATIVE_INFINITY
540 ...(this.workerChoiceStrategiesContext
.getTaskStatisticsRequirements()
544 this.workerNodes
.reduce
<number[]>(
545 (accumulator
, workerNode
) =>
547 workerNode
.usage
.elu
.active
.history
.toArray()
554 ...(this.workerChoiceStrategiesContext
.getTaskStatisticsRequirements()
558 this.workerNodes
.reduce
<number[]>(
559 (accumulator
, workerNode
) =>
561 workerNode
.usage
.elu
.active
.history
.toArray()
572 this.workerNodes
.map(
573 workerNode
=> workerNode
.usage
.elu
.utilization
?? 0
579 this.workerNodes
.map(
580 workerNode
=> workerNode
.usage
.elu
.utilization
?? 0
591 * The pool readiness boolean status.
592 * @returns The pool readiness status.
594 private get
ready (): boolean {
599 this.workerNodes
.reduce(
600 (accumulator
, workerNode
) =>
601 !workerNode
.info
.dynamic
&& workerNode
.info
.ready
605 ) >= this.minimumNumberOfWorkers
610 * The pool emptiness boolean status.
611 * @returns The pool emptiness status.
613 protected get
empty (): boolean {
614 return this.minimumNumberOfWorkers
=== 0 && this.workerNodes
.length
=== 0
618 * The approximate pool utilization.
619 * @returns The pool utilization.
621 private get
utilization (): number {
622 if (this.startTimestamp
== null) {
625 const poolTimeCapacity
=
626 (performance
.now() - this.startTimestamp
) *
627 (this.maximumNumberOfWorkers
?? this.minimumNumberOfWorkers
)
628 const totalTasksRunTime
= this.workerNodes
.reduce(
629 (accumulator
, workerNode
) =>
630 accumulator
+ (workerNode
.usage
.runTime
.aggregate
?? 0),
633 const totalTasksWaitTime
= this.workerNodes
.reduce(
634 (accumulator
, workerNode
) =>
635 accumulator
+ (workerNode
.usage
.waitTime
.aggregate
?? 0),
638 return (totalTasksRunTime
+ totalTasksWaitTime
) / poolTimeCapacity
644 * If it is `'dynamic'`, it provides the `max` property.
646 protected abstract get
type (): PoolType
651 protected abstract get
worker (): WorkerType
654 * Checks if the worker id sent in the received message from a worker is valid.
655 * @param message - The received message.
656 * @throws {@link https://nodejs.org/api/errors.html#class-error} If the worker id is invalid.
658 private checkMessageWorkerId (message
: MessageValue
<Data
| Response
>): void {
659 if (message
.workerId
== null) {
660 throw new Error('Worker message received without worker id')
661 } else if (this.getWorkerNodeKeyByWorkerId(message
.workerId
) === -1) {
663 `Worker message received from unknown worker '${message.workerId.toString()}'`
669 * Gets the worker node key given its worker id.
670 * @param workerId - The worker id.
671 * @returns The worker node key if the worker id is found in the pool worker nodes, `-1` otherwise.
673 private getWorkerNodeKeyByWorkerId (workerId
: number | undefined): number {
674 return this.workerNodes
.findIndex(
675 workerNode
=> workerNode
.info
.id
=== workerId
680 public setWorkerChoiceStrategy (
681 workerChoiceStrategy
: WorkerChoiceStrategy
,
682 workerChoiceStrategyOptions
?: WorkerChoiceStrategyOptions
684 let requireSync
= false
685 checkValidWorkerChoiceStrategy(workerChoiceStrategy
)
686 if (workerChoiceStrategyOptions
!= null) {
687 requireSync
= !this.setWorkerChoiceStrategyOptions(
688 workerChoiceStrategyOptions
691 if (workerChoiceStrategy
!== this.opts
.workerChoiceStrategy
) {
692 this.opts
.workerChoiceStrategy
= workerChoiceStrategy
693 this.workerChoiceStrategiesContext
?.setDefaultWorkerChoiceStrategy(
694 this.opts
.workerChoiceStrategy
,
695 this.opts
.workerChoiceStrategyOptions
700 this.workerChoiceStrategiesContext
?.syncWorkerChoiceStrategies(
701 this.getWorkerChoiceStrategies(),
702 this.opts
.workerChoiceStrategyOptions
704 for (const workerNodeKey
of this.workerNodes
.keys()) {
705 this.sendStatisticsMessageToWorker(workerNodeKey
)
711 public setWorkerChoiceStrategyOptions (
712 workerChoiceStrategyOptions
: WorkerChoiceStrategyOptions
| undefined
714 this.checkValidWorkerChoiceStrategyOptions(workerChoiceStrategyOptions
)
715 if (workerChoiceStrategyOptions
!= null) {
716 this.opts
.workerChoiceStrategyOptions
= workerChoiceStrategyOptions
717 this.workerChoiceStrategiesContext
?.setOptions(
718 this.opts
.workerChoiceStrategyOptions
720 this.workerChoiceStrategiesContext
?.syncWorkerChoiceStrategies(
721 this.getWorkerChoiceStrategies(),
722 this.opts
.workerChoiceStrategyOptions
724 for (const workerNodeKey
of this.workerNodes
.keys()) {
725 this.sendStatisticsMessageToWorker(workerNodeKey
)
733 public enableTasksQueue (
735 tasksQueueOptions
?: TasksQueueOptions
737 if (this.opts
.enableTasksQueue
=== true && !enable
) {
738 this.unsetTaskStealing()
739 this.unsetTasksStealingOnBackPressure()
740 this.flushTasksQueues()
742 this.opts
.enableTasksQueue
= enable
743 this.setTasksQueueOptions(tasksQueueOptions
)
747 public setTasksQueueOptions (
748 tasksQueueOptions
: TasksQueueOptions
| undefined
750 if (this.opts
.enableTasksQueue
=== true) {
751 checkValidTasksQueueOptions(tasksQueueOptions
)
752 this.opts
.tasksQueueOptions
=
753 this.buildTasksQueueOptions(tasksQueueOptions
)
754 // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
755 this.setTasksQueueSize(this.opts
.tasksQueueOptions
.size
!)
756 if (this.opts
.tasksQueueOptions
.taskStealing
=== true) {
757 this.unsetTaskStealing()
758 this.setTaskStealing()
760 this.unsetTaskStealing()
762 if (this.opts
.tasksQueueOptions
.tasksStealingOnBackPressure
=== true) {
763 this.unsetTasksStealingOnBackPressure()
764 this.setTasksStealingOnBackPressure()
766 this.unsetTasksStealingOnBackPressure()
768 } else if (this.opts
.tasksQueueOptions
!= null) {
769 delete this.opts
.tasksQueueOptions
773 private buildTasksQueueOptions (
774 tasksQueueOptions
: TasksQueueOptions
| undefined
775 ): TasksQueueOptions
{
777 ...getDefaultTasksQueueOptions(
778 this.maximumNumberOfWorkers
?? this.minimumNumberOfWorkers
780 ...tasksQueueOptions
,
784 private setTasksQueueSize (size
: number): void {
785 for (const workerNode
of this.workerNodes
) {
786 workerNode
.tasksQueueBackPressureSize
= size
790 private setTaskStealing (): void {
791 for (const workerNodeKey
of this.workerNodes
.keys()) {
792 this.workerNodes
[workerNodeKey
].on('idle', this.handleWorkerNodeIdleEvent
)
796 private unsetTaskStealing (): void {
797 for (const workerNodeKey
of this.workerNodes
.keys()) {
798 this.workerNodes
[workerNodeKey
].off(
800 this.handleWorkerNodeIdleEvent
805 private setTasksStealingOnBackPressure (): void {
806 for (const workerNodeKey
of this.workerNodes
.keys()) {
807 this.workerNodes
[workerNodeKey
].on(
809 this.handleWorkerNodeBackPressureEvent
814 private unsetTasksStealingOnBackPressure (): void {
815 for (const workerNodeKey
of this.workerNodes
.keys()) {
816 this.workerNodes
[workerNodeKey
].off(
818 this.handleWorkerNodeBackPressureEvent
824 * Whether the pool is full or not.
825 * @returns The pool filling boolean status.
827 protected get
full (): boolean {
829 this.workerNodes
.length
>=
830 (this.maximumNumberOfWorkers
?? this.minimumNumberOfWorkers
)
835 * Whether the pool is busy or not.
837 * The pool busyness boolean status.
839 protected abstract get
busy (): boolean
842 * Whether worker nodes are executing concurrently their tasks quota or not.
843 * @returns Worker nodes busyness boolean status.
845 protected internalBusy (): boolean {
846 if (this.opts
.enableTasksQueue
=== true) {
848 this.workerNodes
.findIndex(
850 workerNode
.info
.ready
&&
851 workerNode
.usage
.tasks
.executing
<
852 // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
853 this.opts
.tasksQueueOptions
!.concurrency
!
858 this.workerNodes
.findIndex(
860 workerNode
.info
.ready
&& workerNode
.usage
.tasks
.executing
=== 0
865 private isWorkerNodeBusy (workerNodeKey
: number): boolean {
866 if (this.opts
.enableTasksQueue
=== true) {
868 this.workerNodes
[workerNodeKey
].usage
.tasks
.executing
>=
869 // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
870 this.opts
.tasksQueueOptions
!.concurrency
!
873 return this.workerNodes
[workerNodeKey
].usage
.tasks
.executing
> 0
876 private async sendTaskFunctionOperationToWorker (
877 workerNodeKey
: number,
878 message
: MessageValue
<Data
>
879 ): Promise
<boolean> {
880 return await new Promise
<boolean>((resolve
, reject
) => {
881 const taskFunctionOperationListener
= (
882 message
: MessageValue
<Response
>
884 this.checkMessageWorkerId(message
)
885 const workerId
= this.getWorkerInfo(workerNodeKey
)?.id
887 message
.taskFunctionOperationStatus
!= null &&
888 message
.workerId
=== workerId
890 if (message
.taskFunctionOperationStatus
) {
895 // eslint-disable-next-line @typescript-eslint/restrict-template-expressions
896 `Task function operation '${message.taskFunctionOperation?.toString()}' failed on worker ${message.workerId?.toString()} with error: '${
897 // eslint-disable-next-line @typescript-eslint/restrict-template-expressions
898 message.workerError?.message
903 this.deregisterWorkerMessageListener(
904 this.getWorkerNodeKeyByWorkerId(message
.workerId
),
905 taskFunctionOperationListener
909 this.registerWorkerMessageListener(
911 taskFunctionOperationListener
913 this.sendToWorker(workerNodeKey
, message
)
917 private async sendTaskFunctionOperationToWorkers (
918 message
: MessageValue
<Data
>
919 ): Promise
<boolean> {
920 return await new Promise
<boolean>((resolve
, reject
) => {
921 const responsesReceived
= new Array<MessageValue
<Response
>>()
922 const taskFunctionOperationsListener
= (
923 message
: MessageValue
<Response
>
925 this.checkMessageWorkerId(message
)
926 if (message
.taskFunctionOperationStatus
!= null) {
927 responsesReceived
.push(message
)
928 if (responsesReceived
.length
=== this.workerNodes
.length
) {
930 responsesReceived
.every(
931 message
=> message
.taskFunctionOperationStatus
=== true
936 responsesReceived
.some(
937 message
=> message
.taskFunctionOperationStatus
=== false
940 const errorResponse
= responsesReceived
.find(
941 response
=> response
.taskFunctionOperationStatus
=== false
945 `Task function operation '${
946 message.taskFunctionOperation as string
947 // eslint-disable-next-line @typescript-eslint/restrict-template-expressions
948 }' failed on worker ${errorResponse?.workerId?.toString()} with error: '${
949 // eslint-disable-next-line @typescript-eslint/restrict-template-expressions
950 errorResponse?.workerError?.message
955 this.deregisterWorkerMessageListener(
956 this.getWorkerNodeKeyByWorkerId(message
.workerId
),
957 taskFunctionOperationsListener
962 for (const workerNodeKey
of this.workerNodes
.keys()) {
963 this.registerWorkerMessageListener(
965 taskFunctionOperationsListener
967 this.sendToWorker(workerNodeKey
, message
)
973 public hasTaskFunction (name
: string): boolean {
974 return this.listTaskFunctionsProperties().some(
975 taskFunctionProperties
=> taskFunctionProperties
.name
=== name
980 public async addTaskFunction (
982 fn
: TaskFunction
<Data
, Response
> | TaskFunctionObject
<Data
, Response
>
983 ): Promise
<boolean> {
984 if (typeof name
!== 'string') {
985 throw new TypeError('name argument must be a string')
987 if (typeof name
=== 'string' && name
.trim().length
=== 0) {
988 throw new TypeError('name argument must not be an empty string')
990 if (typeof fn
=== 'function') {
991 fn
= { taskFunction
: fn
} satisfies TaskFunctionObject
<Data
, Response
>
993 if (typeof fn
.taskFunction
!== 'function') {
994 throw new TypeError('taskFunction property must be a function')
996 checkValidPriority(fn
.priority
)
997 checkValidWorkerChoiceStrategy(fn
.strategy
)
998 const opResult
= await this.sendTaskFunctionOperationToWorkers({
999 taskFunctionOperation
: 'add',
1000 taskFunctionProperties
: buildTaskFunctionProperties(name
, fn
),
1001 taskFunction
: fn
.taskFunction
.toString(),
1003 this.taskFunctions
.set(name
, fn
)
1004 this.workerChoiceStrategiesContext
?.syncWorkerChoiceStrategies(
1005 this.getWorkerChoiceStrategies()
1007 for (const workerNodeKey
of this.workerNodes
.keys()) {
1008 this.sendStatisticsMessageToWorker(workerNodeKey
)
1014 public async removeTaskFunction (name
: string): Promise
<boolean> {
1015 if (!this.taskFunctions
.has(name
)) {
1017 'Cannot remove a task function not handled on the pool side'
1020 const opResult
= await this.sendTaskFunctionOperationToWorkers({
1021 taskFunctionOperation
: 'remove',
1022 taskFunctionProperties
: buildTaskFunctionProperties(
1024 this.taskFunctions
.get(name
)
1027 for (const workerNode
of this.workerNodes
) {
1028 workerNode
.deleteTaskFunctionWorkerUsage(name
)
1030 this.taskFunctions
.delete(name
)
1031 this.workerChoiceStrategiesContext
?.syncWorkerChoiceStrategies(
1032 this.getWorkerChoiceStrategies()
1034 for (const workerNodeKey
of this.workerNodes
.keys()) {
1035 this.sendStatisticsMessageToWorker(workerNodeKey
)
1041 public listTaskFunctionsProperties (): TaskFunctionProperties
[] {
1042 for (const workerNode
of this.workerNodes
) {
1044 Array.isArray(workerNode
.info
.taskFunctionsProperties
) &&
1045 workerNode
.info
.taskFunctionsProperties
.length
> 0
1047 return workerNode
.info
.taskFunctionsProperties
1054 * Gets task function worker choice strategy, if any.
1055 * @param name - The task function name.
1056 * @returns The task function worker choice strategy if the task function worker choice strategy is defined, `undefined` otherwise.
1058 private readonly getTaskFunctionWorkerChoiceStrategy
= (
1060 ): WorkerChoiceStrategy
| undefined => {
1061 name
= name
?? DEFAULT_TASK_NAME
1062 const taskFunctionsProperties
= this.listTaskFunctionsProperties()
1063 if (name
=== DEFAULT_TASK_NAME
) {
1064 name
= taskFunctionsProperties
[1]?.name
1066 return taskFunctionsProperties
.find(
1067 (taskFunctionProperties
: TaskFunctionProperties
) =>
1068 taskFunctionProperties
.name
=== name
1073 * Gets worker node task function worker choice strategy, if any.
1074 * @param workerNodeKey - The worker node key.
1075 * @param name - The task function name.
1076 * @returns The worker node task function worker choice strategy if the worker node task function worker choice strategy is defined, `undefined` otherwise.
1078 private readonly getWorkerNodeTaskFunctionWorkerChoiceStrategy
= (
1079 workerNodeKey
: number,
1081 ): WorkerChoiceStrategy
| undefined => {
1082 const workerInfo
= this.getWorkerInfo(workerNodeKey
)
1083 if (workerInfo
== null) {
1086 name
= name
?? DEFAULT_TASK_NAME
1087 if (name
=== DEFAULT_TASK_NAME
) {
1088 name
= workerInfo
.taskFunctionsProperties
?.[1]?.name
1090 return workerInfo
.taskFunctionsProperties
?.find(
1091 (taskFunctionProperties
: TaskFunctionProperties
) =>
1092 taskFunctionProperties
.name
=== name
1097 * Gets worker node task function priority, if any.
1098 * @param workerNodeKey - The worker node key.
1099 * @param name - The task function name.
1100 * @returns The worker node task function priority if the worker node task function priority is defined, `undefined` otherwise.
1102 private readonly getWorkerNodeTaskFunctionPriority
= (
1103 workerNodeKey
: number,
1105 ): number | undefined => {
1106 const workerInfo
= this.getWorkerInfo(workerNodeKey
)
1107 if (workerInfo
== null) {
1110 name
= name
?? DEFAULT_TASK_NAME
1111 if (name
=== DEFAULT_TASK_NAME
) {
1112 name
= workerInfo
.taskFunctionsProperties
?.[1]?.name
1114 return workerInfo
.taskFunctionsProperties
?.find(
1115 (taskFunctionProperties
: TaskFunctionProperties
) =>
1116 taskFunctionProperties
.name
=== name
1121 * Gets the worker choice strategies registered in this pool.
1122 * @returns The worker choice strategies.
1124 private readonly getWorkerChoiceStrategies
=
1125 (): Set
<WorkerChoiceStrategy
> => {
1127 // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
1128 this.opts
.workerChoiceStrategy
!,
1129 ...(this.listTaskFunctionsProperties()
1131 (taskFunctionProperties
: TaskFunctionProperties
) =>
1132 taskFunctionProperties
.strategy
1135 (strategy
: WorkerChoiceStrategy
| undefined) => strategy
!= null
1136 ) as WorkerChoiceStrategy
[]),
1141 public async setDefaultTaskFunction (name
: string): Promise
<boolean> {
1142 return await this.sendTaskFunctionOperationToWorkers({
1143 taskFunctionOperation
: 'default',
1144 taskFunctionProperties
: buildTaskFunctionProperties(
1146 this.taskFunctions
.get(name
)
1151 private shallExecuteTask (workerNodeKey
: number): boolean {
1153 this.tasksQueueSize(workerNodeKey
) === 0 &&
1154 this.workerNodes
[workerNodeKey
].usage
.tasks
.executing
<
1155 // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
1156 this.opts
.tasksQueueOptions
!.concurrency
!
1161 public async execute (
1164 transferList
?: readonly TransferListItem
[]
1165 ): Promise
<Response
> {
1166 return await new Promise
<Response
>((resolve
, reject
) => {
1167 if (!this.started
) {
1168 reject(new Error('Cannot execute a task on not started pool'))
1171 if (this.destroying
) {
1172 reject(new Error('Cannot execute a task on destroying pool'))
1175 if (name
!= null && typeof name
!== 'string') {
1176 reject(new TypeError('name argument must be a string'))
1181 typeof name
=== 'string' &&
1182 name
.trim().length
=== 0
1184 reject(new TypeError('name argument must not be an empty string'))
1187 if (transferList
!= null && !Array.isArray(transferList
)) {
1188 reject(new TypeError('transferList argument must be an array'))
1191 const timestamp
= performance
.now()
1192 const workerNodeKey
= this.chooseWorkerNode(name
)
1193 const task
: Task
<Data
> = {
1194 name
: name
?? DEFAULT_TASK_NAME
,
1195 data
: data
?? ({} as Data
),
1196 priority
: this.getWorkerNodeTaskFunctionPriority(workerNodeKey
, name
),
1197 strategy
: this.getWorkerNodeTaskFunctionWorkerChoiceStrategy(
1203 taskId
: randomUUID(),
1205 // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
1206 this.promiseResponseMap
.set(task
.taskId
!, {
1210 ...(this.emitter
!= null && {
1211 asyncResource
: new AsyncResource('poolifier:task', {
1212 triggerAsyncId
: this.emitter
.asyncId
,
1213 requireManualDestroy
: true,
1218 this.opts
.enableTasksQueue
=== false ||
1219 (this.opts
.enableTasksQueue
=== true &&
1220 this.shallExecuteTask(workerNodeKey
))
1222 this.executeTask(workerNodeKey
, task
)
1224 this.enqueueTask(workerNodeKey
, task
)
1232 data
: Iterable
<Data
>,
1234 transferList
?: readonly TransferListItem
[]
1235 ): Promise
<Response
[]> {
1236 // eslint-disable-next-line @typescript-eslint/no-unnecessary-condition
1238 throw new TypeError('data argument must be a defined iterable')
1240 if (typeof data
[Symbol
.iterator
] !== 'function') {
1241 throw new TypeError('data argument must be an iterable')
1243 if (!Array.isArray(data
)) {
1247 (data
as Data
[]).map(data
=> this.execute(data
, name
, transferList
))
1252 * Starts the minimum number of workers.
1253 * @param initWorkerNodeUsage - Whether to initialize the worker node usage or not. @defaultValue false
1255 private startMinimumNumberOfWorkers (initWorkerNodeUsage
= false): void {
1256 this.startingMinimumNumberOfWorkers
= true
1258 this.workerNodes
.reduce(
1259 (accumulator
, workerNode
) =>
1260 !workerNode
.info
.dynamic
? accumulator
+ 1 : accumulator
,
1262 ) < this.minimumNumberOfWorkers
1264 const workerNodeKey
= this.createAndSetupWorkerNode()
1265 initWorkerNodeUsage
&&
1266 this.initWorkerNodeUsage(this.workerNodes
[workerNodeKey
])
1268 this.startingMinimumNumberOfWorkers
= false
1272 public start (): void {
1274 throw new Error('Cannot start an already started pool')
1276 if (this.starting
) {
1277 throw new Error('Cannot start an already starting pool')
1279 if (this.destroying
) {
1280 throw new Error('Cannot start a destroying pool')
1282 this.starting
= true
1283 this.startMinimumNumberOfWorkers()
1284 this.startTimestamp
= performance
.now()
1285 this.starting
= false
1290 public async destroy (): Promise
<void> {
1291 if (!this.started
) {
1292 throw new Error('Cannot destroy an already destroyed pool')
1294 if (this.starting
) {
1295 throw new Error('Cannot destroy an starting pool')
1297 if (this.destroying
) {
1298 throw new Error('Cannot destroy an already destroying pool')
1300 this.destroying
= true
1302 this.workerNodes
.map(async (_
, workerNodeKey
) => {
1303 await this.destroyWorkerNode(workerNodeKey
)
1306 this.emitter
?.emit(PoolEvents
.destroy
, this.info
)
1307 this.emitter
?.emitDestroy()
1308 this.readyEventEmitted
= false
1309 delete this.startTimestamp
1310 this.destroying
= false
1311 this.started
= false
1314 private async sendKillMessageToWorker (workerNodeKey
: number): Promise
<void> {
1315 await new Promise
<void>((resolve
, reject
) => {
1316 // eslint-disable-next-line @typescript-eslint/no-unnecessary-condition
1317 if (this.workerNodes
[workerNodeKey
] == null) {
1321 const killMessageListener
= (message
: MessageValue
<Response
>): void => {
1322 this.checkMessageWorkerId(message
)
1323 if (message
.kill
=== 'success') {
1325 } else if (message
.kill
=== 'failure') {
1328 // eslint-disable-next-line @typescript-eslint/restrict-template-expressions
1329 `Kill message handling failed on worker ${message.workerId?.toString()}`
1334 // FIXME: should be registered only once
1335 this.registerWorkerMessageListener(workerNodeKey
, killMessageListener
)
1336 this.sendToWorker(workerNodeKey
, { kill
: true })
1341 * Terminates the worker node given its worker node key.
1342 * @param workerNodeKey - The worker node key.
1344 protected async destroyWorkerNode (workerNodeKey
: number): Promise
<void> {
1345 this.flagWorkerNodeAsNotReady(workerNodeKey
)
1346 const flushedTasks
= this.flushTasksQueue(workerNodeKey
)
1347 const workerNode
= this.workerNodes
[workerNodeKey
]
1348 await waitWorkerNodeEvents(
1352 this.opts
.tasksQueueOptions
?.tasksFinishedTimeout
??
1353 getDefaultTasksQueueOptions(
1354 this.maximumNumberOfWorkers
?? this.minimumNumberOfWorkers
1355 ).tasksFinishedTimeout
1357 await this.sendKillMessageToWorker(workerNodeKey
)
1358 await workerNode
.terminate()
1362 * Setup hook to execute code before worker nodes are created in the abstract constructor.
1363 * Can be overridden.
1365 protected setupHook (): void {
1366 /* Intentionally empty */
1370 * Returns whether the worker is the main worker or not.
1371 * @returns `true` if the worker is the main worker, `false` otherwise.
1373 protected abstract isMain (): boolean
1376 * Hook executed before the worker task execution.
1377 * Can be overridden.
1378 * @param workerNodeKey - The worker node key.
1379 * @param task - The task to execute.
1381 protected beforeTaskExecutionHook (
1382 workerNodeKey
: number,
1385 // eslint-disable-next-line @typescript-eslint/no-unnecessary-condition
1386 if (this.workerNodes
[workerNodeKey
]?.usage
!= null) {
1387 const workerUsage
= this.workerNodes
[workerNodeKey
].usage
1388 ++workerUsage
.tasks
.executing
1389 updateWaitTimeWorkerUsage(
1390 this.workerChoiceStrategiesContext
,
1396 this.shallUpdateTaskFunctionWorkerUsage(workerNodeKey
) &&
1397 // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
1398 this.workerNodes
[workerNodeKey
].getTaskFunctionWorkerUsage(task
.name
!) !=
1401 // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
1402 const taskFunctionWorkerUsage
= this.workerNodes
[
1404 // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
1405 ].getTaskFunctionWorkerUsage(task
.name
!)!
1406 ++taskFunctionWorkerUsage
.tasks
.executing
1407 updateWaitTimeWorkerUsage(
1408 this.workerChoiceStrategiesContext
,
1409 taskFunctionWorkerUsage
,
1416 * Hook executed after the worker task execution.
1417 * Can be overridden.
1418 * @param workerNodeKey - The worker node key.
1419 * @param message - The received message.
1421 protected afterTaskExecutionHook (
1422 workerNodeKey
: number,
1423 message
: MessageValue
<Response
>
1425 let needWorkerChoiceStrategiesUpdate
= false
1426 // eslint-disable-next-line @typescript-eslint/no-unnecessary-condition
1427 if (this.workerNodes
[workerNodeKey
]?.usage
!= null) {
1428 const workerUsage
= this.workerNodes
[workerNodeKey
].usage
1429 updateTaskStatisticsWorkerUsage(workerUsage
, message
)
1430 updateRunTimeWorkerUsage(
1431 this.workerChoiceStrategiesContext
,
1435 updateEluWorkerUsage(
1436 this.workerChoiceStrategiesContext
,
1440 needWorkerChoiceStrategiesUpdate
= true
1443 this.shallUpdateTaskFunctionWorkerUsage(workerNodeKey
) &&
1444 this.workerNodes
[workerNodeKey
].getTaskFunctionWorkerUsage(
1445 // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
1446 message
.taskPerformance
!.name
1449 // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
1450 const taskFunctionWorkerUsage
= this.workerNodes
[
1452 // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
1453 ].getTaskFunctionWorkerUsage(message
.taskPerformance
!.name
)!
1454 updateTaskStatisticsWorkerUsage(taskFunctionWorkerUsage
, message
)
1455 updateRunTimeWorkerUsage(
1456 this.workerChoiceStrategiesContext
,
1457 taskFunctionWorkerUsage
,
1460 updateEluWorkerUsage(
1461 this.workerChoiceStrategiesContext
,
1462 taskFunctionWorkerUsage
,
1465 needWorkerChoiceStrategiesUpdate
= true
1467 if (needWorkerChoiceStrategiesUpdate
) {
1468 this.workerChoiceStrategiesContext
?.update(workerNodeKey
)
1473 * Whether the worker node shall update its task function worker usage or not.
1474 * @param workerNodeKey - The worker node key.
1475 * @returns `true` if the worker node shall update its task function worker usage, `false` otherwise.
1477 private shallUpdateTaskFunctionWorkerUsage (workerNodeKey
: number): boolean {
1478 const workerInfo
= this.getWorkerInfo(workerNodeKey
)
1480 workerInfo
!= null &&
1481 Array.isArray(workerInfo
.taskFunctionsProperties
) &&
1482 workerInfo
.taskFunctionsProperties
.length
> 2
1487 * Chooses a worker node for the next task.
1488 * @param name - The task function name.
1489 * @returns The chosen worker node key.
1491 private chooseWorkerNode (name
?: string): number {
1492 if (this.shallCreateDynamicWorker()) {
1493 const workerNodeKey
= this.createAndSetupDynamicWorkerNode()
1495 this.workerChoiceStrategiesContext
?.getPolicy().dynamicWorkerUsage
===
1498 return workerNodeKey
1501 // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
1502 return this.workerChoiceStrategiesContext
!.execute(
1503 this.getTaskFunctionWorkerChoiceStrategy(name
)
1508 * Conditions for dynamic worker creation.
1509 * @returns Whether to create a dynamic worker or not.
1511 protected abstract shallCreateDynamicWorker (): boolean
1514 * Sends a message to worker given its worker node key.
1515 * @param workerNodeKey - The worker node key.
1516 * @param message - The message.
1517 * @param transferList - The optional array of transferable objects.
1519 protected abstract sendToWorker (
1520 workerNodeKey
: number,
1521 message
: MessageValue
<Data
>,
1522 transferList
?: readonly TransferListItem
[]
1526 * Initializes the worker node usage with sensible default values gathered during runtime.
1527 * @param workerNode - The worker node.
1529 private initWorkerNodeUsage (workerNode
: IWorkerNode
<Worker
, Data
>): void {
1531 this.workerChoiceStrategiesContext
?.getTaskStatisticsRequirements()
1532 .runTime
.aggregate
=== true
1534 workerNode
.usage
.runTime
.aggregate
= min(
1535 ...this.workerNodes
.map(
1537 workerNode
.usage
.runTime
.aggregate
?? Number.POSITIVE_INFINITY
1542 this.workerChoiceStrategiesContext
?.getTaskStatisticsRequirements()
1543 .waitTime
.aggregate
=== true
1545 workerNode
.usage
.waitTime
.aggregate
= min(
1546 ...this.workerNodes
.map(
1548 workerNode
.usage
.waitTime
.aggregate
?? Number.POSITIVE_INFINITY
1553 this.workerChoiceStrategiesContext
?.getTaskStatisticsRequirements().elu
1556 workerNode
.usage
.elu
.active
.aggregate
= min(
1557 ...this.workerNodes
.map(
1559 workerNode
.usage
.elu
.active
.aggregate
?? Number.POSITIVE_INFINITY
1566 * Creates a new, completely set up worker node.
1567 * @returns New, completely set up worker node key.
1569 protected createAndSetupWorkerNode (): number {
1570 const workerNode
= this.createWorkerNode()
1571 workerNode
.registerWorkerEventHandler(
1573 this.opts
.onlineHandler
?? EMPTY_FUNCTION
1575 workerNode
.registerWorkerEventHandler(
1577 this.opts
.messageHandler
?? EMPTY_FUNCTION
1579 workerNode
.registerWorkerEventHandler(
1581 this.opts
.errorHandler
?? EMPTY_FUNCTION
1583 workerNode
.registerOnceWorkerEventHandler('error', (error
: Error) => {
1584 workerNode
.info
.ready
= false
1585 this.emitter
?.emit(PoolEvents
.error
, error
)
1589 this.opts
.restartWorkerOnError
=== true
1591 if (workerNode
.info
.dynamic
) {
1592 this.createAndSetupDynamicWorkerNode()
1593 } else if (!this.startingMinimumNumberOfWorkers
) {
1594 this.startMinimumNumberOfWorkers(true)
1600 this.opts
.enableTasksQueue
=== true
1602 this.redistributeQueuedTasks(this.workerNodes
.indexOf(workerNode
))
1604 // eslint-disable-next-line @typescript-eslint/no-unnecessary-condition
1605 workerNode
?.terminate().catch((error
: unknown
) => {
1606 this.emitter
?.emit(PoolEvents
.error
, error
)
1609 workerNode
.registerWorkerEventHandler(
1611 this.opts
.exitHandler
?? EMPTY_FUNCTION
1613 workerNode
.registerOnceWorkerEventHandler('exit', () => {
1614 this.removeWorkerNode(workerNode
)
1617 !this.startingMinimumNumberOfWorkers
&&
1620 this.startMinimumNumberOfWorkers(true)
1623 const workerNodeKey
= this.addWorkerNode(workerNode
)
1624 this.afterWorkerNodeSetup(workerNodeKey
)
1625 return workerNodeKey
1629 * Creates a new, completely set up dynamic worker node.
1630 * @returns New, completely set up dynamic worker node key.
1632 protected createAndSetupDynamicWorkerNode (): number {
1633 const workerNodeKey
= this.createAndSetupWorkerNode()
1634 this.registerWorkerMessageListener(workerNodeKey
, message
=> {
1635 this.checkMessageWorkerId(message
)
1636 const localWorkerNodeKey
= this.getWorkerNodeKeyByWorkerId(
1639 const workerInfo
= this.getWorkerInfo(localWorkerNodeKey
)
1640 const workerUsage
= this.workerNodes
[localWorkerNodeKey
]?.usage
1641 // Kill message received from worker
1643 isKillBehavior(KillBehaviors
.HARD
, message
.kill
) ||
1644 (isKillBehavior(KillBehaviors
.SOFT
, message
.kill
) &&
1645 ((this.opts
.enableTasksQueue
=== false &&
1646 workerUsage
.tasks
.executing
=== 0) ||
1647 (this.opts
.enableTasksQueue
=== true &&
1648 workerInfo
!= null &&
1649 !workerInfo
.stealing
&&
1650 workerUsage
.tasks
.executing
=== 0 &&
1651 this.tasksQueueSize(localWorkerNodeKey
) === 0)))
1653 // Flag the worker node as not ready immediately
1654 this.flagWorkerNodeAsNotReady(localWorkerNodeKey
)
1655 this.destroyWorkerNode(localWorkerNodeKey
).catch((error
: unknown
) => {
1656 this.emitter
?.emit(PoolEvents
.error
, error
)
1660 this.sendToWorker(workerNodeKey
, {
1663 if (this.taskFunctions
.size
> 0) {
1664 for (const [taskFunctionName
, taskFunctionObject
] of this.taskFunctions
) {
1665 this.sendTaskFunctionOperationToWorker(workerNodeKey
, {
1666 taskFunctionOperation
: 'add',
1667 taskFunctionProperties
: buildTaskFunctionProperties(
1671 taskFunction
: taskFunctionObject
.taskFunction
.toString(),
1672 }).catch((error
: unknown
) => {
1673 this.emitter
?.emit(PoolEvents
.error
, error
)
1677 const workerNode
= this.workerNodes
[workerNodeKey
]
1678 workerNode
.info
.dynamic
= true
1680 this.workerChoiceStrategiesContext
?.getPolicy().dynamicWorkerReady
===
1682 this.workerChoiceStrategiesContext
?.getPolicy().dynamicWorkerUsage
===
1685 workerNode
.info
.ready
= true
1687 this.initWorkerNodeUsage(workerNode
)
1688 this.checkAndEmitDynamicWorkerCreationEvents()
1689 return workerNodeKey
1693 * Registers a listener callback on the worker given its worker node key.
1694 * @param workerNodeKey - The worker node key.
1695 * @param listener - The message listener callback.
1697 protected abstract registerWorkerMessageListener
<
1698 Message
extends Data
| Response
1700 workerNodeKey
: number,
1701 listener
: (message
: MessageValue
<Message
>) => void
1705 * Registers once a listener callback on the worker given its worker node key.
1706 * @param workerNodeKey - The worker node key.
1707 * @param listener - The message listener callback.
1709 protected abstract registerOnceWorkerMessageListener
<
1710 Message
extends Data
| Response
1712 workerNodeKey
: number,
1713 listener
: (message
: MessageValue
<Message
>) => void
1717 * Deregisters a listener callback on the worker given its worker node key.
1718 * @param workerNodeKey - The worker node key.
1719 * @param listener - The message listener callback.
1721 protected abstract deregisterWorkerMessageListener
<
1722 Message
extends Data
| Response
1724 workerNodeKey
: number,
1725 listener
: (message
: MessageValue
<Message
>) => void
1729 * Method hooked up after a worker node has been newly created.
1730 * Can be overridden.
1731 * @param workerNodeKey - The newly created worker node key.
1733 protected afterWorkerNodeSetup (workerNodeKey
: number): void {
1734 // Listen to worker messages.
1735 this.registerWorkerMessageListener(
1737 this.workerMessageListener
1739 // Send the startup message to worker.
1740 this.sendStartupMessageToWorker(workerNodeKey
)
1741 // Send the statistics message to worker.
1742 this.sendStatisticsMessageToWorker(workerNodeKey
)
1743 if (this.opts
.enableTasksQueue
=== true) {
1744 if (this.opts
.tasksQueueOptions
?.taskStealing
=== true) {
1745 this.workerNodes
[workerNodeKey
].on(
1747 this.handleWorkerNodeIdleEvent
1750 if (this.opts
.tasksQueueOptions
?.tasksStealingOnBackPressure
=== true) {
1751 this.workerNodes
[workerNodeKey
].on(
1753 this.handleWorkerNodeBackPressureEvent
1760 * Sends the startup message to worker given its worker node key.
1761 * @param workerNodeKey - The worker node key.
1763 protected abstract sendStartupMessageToWorker (workerNodeKey
: number): void
1766 * Sends the statistics message to worker given its worker node key.
1767 * @param workerNodeKey - The worker node key.
1769 private sendStatisticsMessageToWorker (workerNodeKey
: number): void {
1770 this.sendToWorker(workerNodeKey
, {
1773 this.workerChoiceStrategiesContext
?.getTaskStatisticsRequirements()
1774 .runTime
.aggregate
?? false,
1776 this.workerChoiceStrategiesContext
?.getTaskStatisticsRequirements()
1777 .elu
.aggregate
?? false,
1782 private cannotStealTask (): boolean {
1783 return this.workerNodes
.length
<= 1 || this.info
.queuedTasks
=== 0
1786 private handleTask (workerNodeKey
: number, task
: Task
<Data
>): void {
1787 if (this.shallExecuteTask(workerNodeKey
)) {
1788 this.executeTask(workerNodeKey
, task
)
1790 this.enqueueTask(workerNodeKey
, task
)
1794 private redistributeQueuedTasks (sourceWorkerNodeKey
: number): void {
1795 if (sourceWorkerNodeKey
=== -1 || this.cannotStealTask()) {
1798 while (this.tasksQueueSize(sourceWorkerNodeKey
) > 0) {
1799 const destinationWorkerNodeKey
= this.workerNodes
.reduce(
1800 (minWorkerNodeKey
, workerNode
, workerNodeKey
, workerNodes
) => {
1801 return sourceWorkerNodeKey
!== workerNodeKey
&&
1802 workerNode
.info
.ready
&&
1803 workerNode
.usage
.tasks
.queued
<
1804 workerNodes
[minWorkerNodeKey
].usage
.tasks
.queued
1811 destinationWorkerNodeKey
,
1812 // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
1813 this.dequeueTask(sourceWorkerNodeKey
)!
1818 private updateTaskStolenStatisticsWorkerUsage (
1819 workerNodeKey
: number,
1822 const workerNode
= this.workerNodes
[workerNodeKey
]
1823 // eslint-disable-next-line @typescript-eslint/no-unnecessary-condition
1824 if (workerNode
?.usage
!= null) {
1825 ++workerNode
.usage
.tasks
.stolen
1828 this.shallUpdateTaskFunctionWorkerUsage(workerNodeKey
) &&
1829 workerNode
.getTaskFunctionWorkerUsage(taskName
) != null
1831 // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
1832 ++workerNode
.getTaskFunctionWorkerUsage(taskName
)!.tasks
.stolen
1836 private updateTaskSequentiallyStolenStatisticsWorkerUsage (
1837 workerNodeKey
: number,
1839 previousTaskName
?: string
1841 const workerNode
= this.workerNodes
[workerNodeKey
]
1842 // eslint-disable-next-line @typescript-eslint/no-unnecessary-condition
1843 if (workerNode
?.usage
!= null) {
1844 ++workerNode
.usage
.tasks
.sequentiallyStolen
1847 this.shallUpdateTaskFunctionWorkerUsage(workerNodeKey
) &&
1848 workerNode
.getTaskFunctionWorkerUsage(taskName
) != null
1850 const taskFunctionWorkerUsage
=
1851 // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
1852 workerNode
.getTaskFunctionWorkerUsage(taskName
)!
1854 taskFunctionWorkerUsage
.tasks
.sequentiallyStolen
=== 0 ||
1855 (previousTaskName
!= null &&
1856 previousTaskName
=== taskName
&&
1857 taskFunctionWorkerUsage
.tasks
.sequentiallyStolen
> 0)
1859 ++taskFunctionWorkerUsage
.tasks
.sequentiallyStolen
1860 } else if (taskFunctionWorkerUsage
.tasks
.sequentiallyStolen
> 0) {
1861 taskFunctionWorkerUsage
.tasks
.sequentiallyStolen
= 0
1866 private resetTaskSequentiallyStolenStatisticsWorkerUsage (
1867 workerNodeKey
: number,
1870 const workerNode
= this.workerNodes
[workerNodeKey
]
1871 // eslint-disable-next-line @typescript-eslint/no-unnecessary-condition
1872 if (workerNode
?.usage
!= null) {
1873 workerNode
.usage
.tasks
.sequentiallyStolen
= 0
1876 this.shallUpdateTaskFunctionWorkerUsage(workerNodeKey
) &&
1877 workerNode
.getTaskFunctionWorkerUsage(taskName
) != null
1879 // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
1880 workerNode
.getTaskFunctionWorkerUsage(
1882 )!.tasks
.sequentiallyStolen
= 0
1886 private readonly handleWorkerNodeIdleEvent
= (
1887 eventDetail
: WorkerNodeEventDetail
,
1888 previousStolenTask
?: Task
<Data
>
1890 const { workerNodeKey
} = eventDetail
1891 if (workerNodeKey
== null) {
1893 "WorkerNode event detail 'workerNodeKey' property must be defined"
1896 const workerInfo
= this.getWorkerInfo(workerNodeKey
)
1897 if (workerInfo
== null) {
1899 `Worker node with key '${workerNodeKey.toString()}' not found in pool`
1903 this.cannotStealTask() ||
1904 (this.info
.stealingWorkerNodes
?? 0) >
1905 Math.floor(this.workerNodes
.length
/ 2)
1907 if (previousStolenTask
!= null) {
1908 workerInfo
.stealing
= false
1909 this.resetTaskSequentiallyStolenStatisticsWorkerUsage(
1911 // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
1912 previousStolenTask
.name
!
1917 const workerNodeTasksUsage
= this.workerNodes
[workerNodeKey
].usage
.tasks
1919 previousStolenTask
!= null &&
1920 (workerNodeTasksUsage
.executing
> 0 ||
1921 this.tasksQueueSize(workerNodeKey
) > 0)
1923 workerInfo
.stealing
= false
1924 this.resetTaskSequentiallyStolenStatisticsWorkerUsage(
1926 // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
1927 previousStolenTask
.name
!
1931 workerInfo
.stealing
= true
1932 const stolenTask
= this.workerNodeStealTask(workerNodeKey
)
1933 if (stolenTask
!= null) {
1934 this.updateTaskSequentiallyStolenStatisticsWorkerUsage(
1936 // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
1938 previousStolenTask
?.name
1941 sleep(exponentialDelay(workerNodeTasksUsage
.sequentiallyStolen
))
1943 this.handleWorkerNodeIdleEvent(eventDetail
, stolenTask
)
1946 .catch((error
: unknown
) => {
1947 this.emitter
?.emit(PoolEvents
.error
, error
)
1951 private readonly workerNodeStealTask
= (
1952 workerNodeKey
: number
1953 ): Task
<Data
> | undefined => {
1954 const workerNodes
= this.workerNodes
1957 (workerNodeA
, workerNodeB
) =>
1958 workerNodeB
.usage
.tasks
.queued
- workerNodeA
.usage
.tasks
.queued
1960 const sourceWorkerNode
= workerNodes
.find(
1961 (sourceWorkerNode
, sourceWorkerNodeKey
) =>
1962 sourceWorkerNode
.info
.ready
&&
1963 !sourceWorkerNode
.info
.stealing
&&
1964 sourceWorkerNodeKey
!== workerNodeKey
&&
1965 sourceWorkerNode
.usage
.tasks
.queued
> 0
1967 if (sourceWorkerNode
!= null) {
1968 // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
1969 const task
= sourceWorkerNode
.dequeueLastPrioritizedTask()!
1970 this.handleTask(workerNodeKey
, task
)
1971 // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
1972 this.updateTaskStolenStatisticsWorkerUsage(workerNodeKey
, task
.name
!)
1977 private readonly handleWorkerNodeBackPressureEvent
= (
1978 eventDetail
: WorkerNodeEventDetail
1981 this.cannotStealTask() ||
1982 this.hasBackPressure() ||
1983 (this.info
.stealingWorkerNodes
?? 0) >
1984 Math.floor(this.workerNodes
.length
/ 2)
1988 const sizeOffset
= 1
1989 // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
1990 if (this.opts
.tasksQueueOptions
!.size
! <= sizeOffset
) {
1993 const { workerId
} = eventDetail
1994 const sourceWorkerNode
=
1995 this.workerNodes
[this.getWorkerNodeKeyByWorkerId(workerId
)]
1996 const workerNodes
= this.workerNodes
1999 (workerNodeA
, workerNodeB
) =>
2000 workerNodeA
.usage
.tasks
.queued
- workerNodeB
.usage
.tasks
.queued
2002 for (const [workerNodeKey
, workerNode
] of workerNodes
.entries()) {
2004 sourceWorkerNode
.usage
.tasks
.queued
> 0 &&
2005 workerNode
.info
.ready
&&
2006 !workerNode
.info
.stealing
&&
2007 workerNode
.info
.id
!== workerId
&&
2008 workerNode
.usage
.tasks
.queued
<
2009 // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
2010 this.opts
.tasksQueueOptions
!.size
! - sizeOffset
2012 const workerInfo
= this.getWorkerInfo(workerNodeKey
)
2013 if (workerInfo
== null) {
2015 `Worker node with key '${workerNodeKey.toString()}' not found in pool`
2018 workerInfo
.stealing
= true
2019 // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
2020 const task
= sourceWorkerNode
.dequeueLastPrioritizedTask()!
2021 this.handleTask(workerNodeKey
, task
)
2022 // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
2023 this.updateTaskStolenStatisticsWorkerUsage(workerNodeKey
, task
.name
!)
2024 workerInfo
.stealing
= false
2029 private setTasksQueuePriority (workerNodeKey
: number): void {
2030 this.workerNodes
[workerNodeKey
].setTasksQueuePriority(
2031 this.getTasksQueuePriority()
2036 * This method is the message listener registered on each worker.
2037 * @param message - The message received from the worker.
2039 protected readonly workerMessageListener
= (
2040 message
: MessageValue
<Response
>
2042 this.checkMessageWorkerId(message
)
2043 const { workerId
, ready
, taskId
, taskFunctionsProperties
} = message
2044 if (ready
!= null && taskFunctionsProperties
!= null) {
2045 // Worker ready response received from worker
2046 this.handleWorkerReadyResponse(message
)
2047 } else if (taskFunctionsProperties
!= null) {
2048 // Task function properties message received from worker
2049 const workerNodeKey
= this.getWorkerNodeKeyByWorkerId(workerId
)
2050 const workerInfo
= this.getWorkerInfo(workerNodeKey
)
2051 if (workerInfo
!= null) {
2052 workerInfo
.taskFunctionsProperties
= taskFunctionsProperties
2053 this.sendStatisticsMessageToWorker(workerNodeKey
)
2054 this.setTasksQueuePriority(workerNodeKey
)
2056 } else if (taskId
!= null) {
2057 // Task execution response received from worker
2058 this.handleTaskExecutionResponse(message
)
2062 private checkAndEmitReadyEvent (): void {
2063 if (!this.readyEventEmitted
&& this.ready
) {
2064 this.emitter
?.emit(PoolEvents
.ready
, this.info
)
2065 this.readyEventEmitted
= true
2069 private handleWorkerReadyResponse (message
: MessageValue
<Response
>): void {
2070 const { workerId
, ready
, taskFunctionsProperties
} = message
2071 if (ready
== null || !ready
) {
2072 // eslint-disable-next-line @typescript-eslint/restrict-template-expressions
2073 throw new Error(`Worker ${workerId?.toString()} failed to initialize`)
2075 const workerNodeKey
= this.getWorkerNodeKeyByWorkerId(workerId
)
2076 const workerNode
= this.workerNodes
[workerNodeKey
]
2077 workerNode
.info
.ready
= ready
2078 workerNode
.info
.taskFunctionsProperties
= taskFunctionsProperties
2079 this.sendStatisticsMessageToWorker(workerNodeKey
)
2080 this.setTasksQueuePriority(workerNodeKey
)
2081 this.checkAndEmitReadyEvent()
2084 private handleTaskExecutionResponse (message
: MessageValue
<Response
>): void {
2085 const { workerId
, taskId
, workerError
, data
} = message
2086 // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
2087 const promiseResponse
= this.promiseResponseMap
.get(taskId
!)
2088 if (promiseResponse
!= null) {
2089 const { resolve
, reject
, workerNodeKey
, asyncResource
} = promiseResponse
2090 const workerNode
= this.workerNodes
[workerNodeKey
]
2091 if (workerError
!= null) {
2092 this.emitter
?.emit(PoolEvents
.taskError
, workerError
)
2093 asyncResource
!= null
2094 ? asyncResource
.runInAsyncScope(
2099 : reject(workerError
.message
)
2101 asyncResource
!= null
2102 ? asyncResource
.runInAsyncScope(resolve
, this.emitter
, data
)
2103 : resolve(data
as Response
)
2105 asyncResource
?.emitDestroy()
2106 this.afterTaskExecutionHook(workerNodeKey
, message
)
2107 // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
2108 this.promiseResponseMap
.delete(taskId
!)
2109 // eslint-disable-next-line @typescript-eslint/no-unnecessary-condition
2110 workerNode
?.emit('taskFinished', taskId
)
2112 this.opts
.enableTasksQueue
=== true &&
2114 // eslint-disable-next-line @typescript-eslint/no-unnecessary-condition
2117 const workerNodeTasksUsage
= workerNode
.usage
.tasks
2119 this.tasksQueueSize(workerNodeKey
) > 0 &&
2120 workerNodeTasksUsage
.executing
<
2121 // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
2122 this.opts
.tasksQueueOptions
!.concurrency
!
2124 // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
2125 this.executeTask(workerNodeKey
, this.dequeueTask(workerNodeKey
)!)
2128 workerNodeTasksUsage
.executing
=== 0 &&
2129 this.tasksQueueSize(workerNodeKey
) === 0 &&
2130 workerNodeTasksUsage
.sequentiallyStolen
=== 0
2132 workerNode
.emit('idle', {
2141 private checkAndEmitTaskExecutionEvents (): void {
2143 this.emitter
?.emit(PoolEvents
.busy
, this.info
)
2147 private checkAndEmitTaskQueuingEvents (): void {
2148 if (this.hasBackPressure()) {
2149 this.emitter
?.emit(PoolEvents
.backPressure
, this.info
)
2154 * Emits dynamic worker creation events.
2156 protected abstract checkAndEmitDynamicWorkerCreationEvents (): void
2159 * Gets the worker information given its worker node key.
2160 * @param workerNodeKey - The worker node key.
2161 * @returns The worker information.
2163 protected getWorkerInfo (workerNodeKey
: number): WorkerInfo
| undefined {
2164 return this.workerNodes
[workerNodeKey
]?.info
2167 private getTasksQueuePriority (): boolean {
2168 return this.listTaskFunctionsProperties().some(
2169 taskFunctionProperties
=> taskFunctionProperties
.priority
!= null
2174 * Creates a worker node.
2175 * @returns The created worker node.
2177 private createWorkerNode (): IWorkerNode
<Worker
, Data
> {
2178 const workerNode
= new WorkerNode
<Worker
, Data
>(
2183 workerOptions
: this.opts
.workerOptions
,
2184 tasksQueueBackPressureSize
:
2185 this.opts
.tasksQueueOptions
?.size
??
2186 getDefaultTasksQueueOptions(
2187 this.maximumNumberOfWorkers
?? this.minimumNumberOfWorkers
2189 tasksQueueBucketSize
: defaultBucketSize
,
2190 tasksQueuePriority
: this.getTasksQueuePriority(),
2193 // Flag the worker node as ready at pool startup.
2194 if (this.starting
) {
2195 workerNode
.info
.ready
= true
2201 * Adds the given worker node in the pool worker nodes.
2202 * @param workerNode - The worker node.
2203 * @returns The added worker node key.
2204 * @throws {@link https://nodejs.org/api/errors.html#class-error} If the added worker node is not found.
2206 private addWorkerNode (workerNode
: IWorkerNode
<Worker
, Data
>): number {
2207 this.workerNodes
.push(workerNode
)
2208 const workerNodeKey
= this.workerNodes
.indexOf(workerNode
)
2209 if (workerNodeKey
=== -1) {
2210 throw new Error('Worker added not found in worker nodes')
2212 return workerNodeKey
2215 private checkAndEmitEmptyEvent (): void {
2217 this.emitter
?.emit(PoolEvents
.empty
, this.info
)
2218 this.readyEventEmitted
= false
2223 * Removes the worker node from the pool worker nodes.
2224 * @param workerNode - The worker node.
2226 private removeWorkerNode (workerNode
: IWorkerNode
<Worker
, Data
>): void {
2227 const workerNodeKey
= this.workerNodes
.indexOf(workerNode
)
2228 if (workerNodeKey
!== -1) {
2229 this.workerNodes
.splice(workerNodeKey
, 1)
2230 this.workerChoiceStrategiesContext
?.remove(workerNodeKey
)
2232 this.checkAndEmitEmptyEvent()
2235 protected flagWorkerNodeAsNotReady (workerNodeKey
: number): void {
2236 const workerInfo
= this.getWorkerInfo(workerNodeKey
)
2237 if (workerInfo
!= null) {
2238 workerInfo
.ready
= false
2242 private hasBackPressure (): boolean {
2244 this.opts
.enableTasksQueue
=== true &&
2245 this.workerNodes
.findIndex(
2246 workerNode
=> !workerNode
.hasBackPressure()
2252 * Executes the given task on the worker given its worker node key.
2253 * @param workerNodeKey - The worker node key.
2254 * @param task - The task to execute.
2256 private executeTask (workerNodeKey
: number, task
: Task
<Data
>): void {
2257 this.beforeTaskExecutionHook(workerNodeKey
, task
)
2258 this.sendToWorker(workerNodeKey
, task
, task
.transferList
)
2259 this.checkAndEmitTaskExecutionEvents()
2262 private enqueueTask (workerNodeKey
: number, task
: Task
<Data
>): number {
2263 const tasksQueueSize
= this.workerNodes
[workerNodeKey
].enqueueTask(task
)
2264 this.checkAndEmitTaskQueuingEvents()
2265 return tasksQueueSize
2268 private dequeueTask (workerNodeKey
: number): Task
<Data
> | undefined {
2269 return this.workerNodes
[workerNodeKey
].dequeueTask()
2272 private tasksQueueSize (workerNodeKey
: number): number {
2273 return this.workerNodes
[workerNodeKey
].tasksQueueSize()
2276 protected flushTasksQueue (workerNodeKey
: number): number {
2277 let flushedTasks
= 0
2278 while (this.tasksQueueSize(workerNodeKey
) > 0) {
2279 // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
2280 this.executeTask(workerNodeKey
, this.dequeueTask(workerNodeKey
)!)
2283 this.workerNodes
[workerNodeKey
].clearTasksQueue()
2287 private flushTasksQueues (): void {
2288 for (const workerNodeKey
of this.workerNodes
.keys()) {
2289 this.flushTasksQueue(workerNodeKey
)