X-Git-Url: https://git.piment-noir.org/?a=blobdiff_plain;f=src%2Fpools%2Fabstract-pool.ts;h=33585218249e599cd1998fdc19158e7ab4b22168;hb=adee605399485348ae224e7e4c022f024373b0ef;hp=a41996ff918d527d2ef81ac29f431cdd601b91c7;hpb=1a880eca683648d5228e2424db74553f58ecee7d;p=poolifier.git

diff --git a/src/pools/abstract-pool.ts b/src/pools/abstract-pool.ts
index a41996ff..33585218 100644
--- a/src/pools/abstract-pool.ts
+++ b/src/pools/abstract-pool.ts
@@ -14,11 +14,14 @@ import {
   average,
   isKillBehavior,
   isPlainObject,
+  max,
   median,
+  min,
   round,
   updateMeasurementStatistics
 } from '../utils'
 import { KillBehaviors } from '../worker/worker-options'
+import type { TaskFunction } from '../worker/task-functions'
 import {
   type IPool,
   PoolEmitter,
@@ -66,8 +69,7 @@ export abstract class AbstractPool<
   public readonly emitter?: PoolEmitter
 
   /**
-   * The task execution response promise map.
-   *
+   * The task execution response promise map:
    * - `key`: The message id of each submitted task.
    * - `value`: An object that contains the worker, the execution response promise resolve and reject callbacks.
    *
@@ -91,13 +93,20 @@ export abstract class AbstractPool<
   protected readonly max?: number
 
   /**
-   * Whether the pool is starting or not.
+   * The task functions added at runtime map:
+   * - `key`: The task function name.
+   * - `value`: The task function itself.
    */
-  private readonly starting: boolean
+  private readonly taskFunctions: Map<string, TaskFunction<Data, Response>>
+
   /**
    * Whether the pool is started or not.
    */
   private started: boolean
+  /**
+   * Whether the pool is starting or not.
+   */
+  private starting: boolean
   /**
    * The start timestamp of the pool.
    */
@@ -143,10 +152,13 @@ export abstract class AbstractPool<
 
     this.setupHook()
 
-    this.starting = true
-    this.startPool()
+    this.taskFunctions = new Map<string, TaskFunction<Data, Response>>()
+
+    this.started = false
     this.starting = false
-    this.started = true
+    if (this.opts.startWorkers === true) {
+      this.start()
+    }
 
     this.startTimestamp = performance.now()
   }
@@ -210,16 +222,19 @@ export abstract class AbstractPool<
 
   private checkPoolOptions (opts: PoolOptions<Worker>): void {
     if (isPlainObject(opts)) {
+      this.opts.startWorkers = opts.startWorkers ?? true
+      this.checkValidWorkerChoiceStrategy(
+        opts.workerChoiceStrategy as WorkerChoiceStrategy
+      )
       this.opts.workerChoiceStrategy =
         opts.workerChoiceStrategy ?? WorkerChoiceStrategies.ROUND_ROBIN
-      this.checkValidWorkerChoiceStrategy(this.opts.workerChoiceStrategy)
+      this.checkValidWorkerChoiceStrategyOptions(
+        opts.workerChoiceStrategyOptions as WorkerChoiceStrategyOptions
+      )
       this.opts.workerChoiceStrategyOptions = {
         ...DEFAULT_WORKER_CHOICE_STRATEGY_OPTIONS,
         ...opts.workerChoiceStrategyOptions
       }
-      this.checkValidWorkerChoiceStrategyOptions(
-        this.opts.workerChoiceStrategyOptions
-      )
       this.opts.restartWorkerOnError = opts.restartWorkerOnError ?? true
       this.opts.enableEvents = opts.enableEvents ?? true
       this.opts.enableTasksQueue = opts.enableTasksQueue ?? false
@@ -239,7 +254,10 @@ export abstract class AbstractPool<
   private checkValidWorkerChoiceStrategy (
     workerChoiceStrategy: WorkerChoiceStrategy
   ): void {
-    if (!Object.values(WorkerChoiceStrategies).includes(workerChoiceStrategy)) {
+    if (
+      workerChoiceStrategy != null &&
+      !Object.values(WorkerChoiceStrategies).includes(workerChoiceStrategy)
+    ) {
       throw new Error(
         `Invalid worker choice strategy '${workerChoiceStrategy}'`
       )
@@ -249,13 +267,16 @@ export abstract class AbstractPool<
   private checkValidWorkerChoiceStrategyOptions (
     workerChoiceStrategyOptions: WorkerChoiceStrategyOptions
   ): void {
-    if (!isPlainObject(workerChoiceStrategyOptions)) {
+    if (
+      workerChoiceStrategyOptions != null &&
+      !isPlainObject(workerChoiceStrategyOptions)
+    ) {
       throw new TypeError(
         'Invalid worker choice strategy options: must be a plain object'
       )
     }
     if (
-      workerChoiceStrategyOptions.retries != null &&
+      workerChoiceStrategyOptions?.retries != null &&
       !Number.isSafeInteger(workerChoiceStrategyOptions.retries)
     ) {
       throw new TypeError(
@@ -263,7 +284,7 @@ export abstract class AbstractPool<
       )
     }
     if (
-      workerChoiceStrategyOptions.retries != null &&
+      workerChoiceStrategyOptions?.retries != null &&
       workerChoiceStrategyOptions.retries < 0
     ) {
       throw new RangeError(
@@ -271,7 +292,7 @@ export abstract class AbstractPool<
       )
     }
     if (
-      workerChoiceStrategyOptions.weights != null &&
+      workerChoiceStrategyOptions?.weights != null &&
       Object.keys(workerChoiceStrategyOptions.weights).length !== this.maxSize
     ) {
       throw new Error(
@@ -279,7 +300,7 @@ export abstract class AbstractPool<
       )
     }
     if (
-      workerChoiceStrategyOptions.measurement != null &&
+      workerChoiceStrategyOptions?.measurement != null &&
       !Object.values(Measurements).includes(
         workerChoiceStrategyOptions.measurement
       )
@@ -312,11 +333,6 @@ export abstract class AbstractPool<
         `Invalid worker node tasks concurrency: ${tasksQueueOptions.concurrency} is a negative integer or zero`
       )
     }
-    if (tasksQueueOptions?.queueMaxSize != null) {
-      throw new Error(
-        'Invalid tasks queue options: queueMaxSize is deprecated, please use size instead'
-      )
-    }
     if (
       tasksQueueOptions?.size != null &&
       !Number.isSafeInteger(tasksQueueOptions.size)
@@ -332,24 +348,13 @@ export abstract class AbstractPool<
     }
   }
 
-  private startPool (): void {
-    while (
-      this.workerNodes.reduce(
-        (accumulator, workerNode) =>
-          !workerNode.info.dynamic ? accumulator + 1 : accumulator,
-        0
-      ) < this.numberOfWorkers
-    ) {
-      this.createAndSetupWorkerNode()
-    }
-  }
-
   /** @inheritDoc */
   public get info (): PoolInfo {
     return {
       version,
       type: this.type,
       worker: this.worker,
+      started: this.started,
       ready: this.ready,
       strategy: this.opts.workerChoiceStrategy as WorkerChoiceStrategy,
       minSize: this.minSize,
@@ -414,16 +419,16 @@ export abstract class AbstractPool<
         .runTime.aggregate && {
         runTime: {
           minimum: round(
-            Math.min(
+            min(
               ...this.workerNodes.map(
-                (workerNode) => workerNode.usage.runTime?.minimum ?? Infinity
+                workerNode => workerNode.usage.runTime?.minimum ?? Infinity
               )
             )
           ),
           maximum: round(
-            Math.max(
+            max(
               ...this.workerNodes.map(
-                (workerNode) => workerNode.usage.runTime?.maximum ?? -Infinity
+                workerNode => workerNode.usage.runTime?.maximum ?? -Infinity
               )
             )
           ),
@@ -457,16 +462,16 @@ export abstract class AbstractPool<
         .waitTime.aggregate && {
         waitTime: {
           minimum: round(
-            Math.min(
+            min(
               ...this.workerNodes.map(
-                (workerNode) => workerNode.usage.waitTime?.minimum ?? Infinity
+                workerNode => workerNode.usage.waitTime?.minimum ?? Infinity
               )
             )
           ),
           maximum: round(
-            Math.max(
+            max(
               ...this.workerNodes.map(
-                (workerNode) => workerNode.usage.waitTime?.maximum ?? -Infinity
+                workerNode => workerNode.usage.waitTime?.maximum ?? -Infinity
               )
             )
           ),
@@ -588,7 +593,7 @@ export abstract class AbstractPool<
    */
   private getWorkerNodeKeyByWorker (worker: Worker): number {
     return this.workerNodes.findIndex(
-      (workerNode) => workerNode.worker === worker
+      workerNode => workerNode.worker === worker
     )
   }
 
@@ -598,9 +603,9 @@ export abstract class AbstractPool<
    * @param workerId - The worker id.
    * @returns The worker node key if the worker id is found in the pool worker nodes, `-1` otherwise.
    */
-  private getWorkerNodeKeyByWorkerId (workerId: number): number {
+  private getWorkerNodeKeyByWorkerId (workerId: number | undefined): number {
     return this.workerNodes.findIndex(
-      (workerNode) => workerNode.info.id === workerId
+      workerNode => workerNode.info.id === workerId
     )
   }
 
@@ -643,6 +648,8 @@ export abstract class AbstractPool<
     tasksQueueOptions?: TasksQueueOptions
   ): void {
     if (this.opts.enableTasksQueue === true && !enable) {
+      this.unsetTaskStealing()
+      this.unsetTasksStealingOnBackPressure()
       this.flushTasksQueues()
     }
     this.opts.enableTasksQueue = enable
@@ -655,30 +662,68 @@ export abstract class AbstractPool<
       this.checkValidTasksQueueOptions(tasksQueueOptions)
       this.opts.tasksQueueOptions =
         this.buildTasksQueueOptions(tasksQueueOptions)
-      this.setTasksQueueMaxSize(this.opts.tasksQueueOptions.size as number)
+      this.setTasksQueueSize(this.opts.tasksQueueOptions.size as number)
+      if (this.opts.tasksQueueOptions.taskStealing === true) {
+        this.setTaskStealing()
+      } else {
+        this.unsetTaskStealing()
+      }
+      if (this.opts.tasksQueueOptions.tasksStealingOnBackPressure === true) {
+        this.setTasksStealingOnBackPressure()
+      } else {
+        this.unsetTasksStealingOnBackPressure()
+      }
     } else if (this.opts.tasksQueueOptions != null) {
       delete this.opts.tasksQueueOptions
     }
   }
 
-  private setTasksQueueMaxSize (size: number): void {
-    for (const workerNode of this.workerNodes) {
-      workerNode.tasksQueueBackPressureSize = size
-    }
-  }
-
   private buildTasksQueueOptions (
     tasksQueueOptions: TasksQueueOptions
   ): TasksQueueOptions {
     return {
       ...{
         size: Math.pow(this.maxSize, 2),
-        concurrency: 1
+        concurrency: 1,
+        taskStealing: true,
+        tasksStealingOnBackPressure: true
       },
       ...tasksQueueOptions
     }
   }
 
+  private setTasksQueueSize (size: number): void {
+    for (const workerNode of this.workerNodes) {
+      workerNode.tasksQueueBackPressureSize = size
+    }
+  }
+
+  private setTaskStealing (): void {
+    for (const [workerNodeKey] of this.workerNodes.entries()) {
+      this.workerNodes[workerNodeKey].onEmptyQueue =
+        this.taskStealingOnEmptyQueue.bind(this)
+    }
+  }
+
+  private unsetTaskStealing (): void {
+    for (const [workerNodeKey] of this.workerNodes.entries()) {
+      delete this.workerNodes[workerNodeKey].onEmptyQueue
+    }
+  }
+
+  private setTasksStealingOnBackPressure (): void {
+    for (const [workerNodeKey] of this.workerNodes.entries()) {
+      this.workerNodes[workerNodeKey].onBackPressure =
+        this.tasksStealingOnBackPressure.bind(this)
+    }
+  }
+
+  private unsetTasksStealingOnBackPressure (): void {
+    for (const [workerNodeKey] of this.workerNodes.entries()) {
+      delete this.workerNodes[workerNodeKey].onBackPressure
+    }
+  }
+
   /**
    * Whether the pool is full or not.
    *
@@ -704,35 +749,166 @@ export abstract class AbstractPool<
     if (this.opts.enableTasksQueue === true) {
       return (
         this.workerNodes.findIndex(
-          (workerNode) =>
+          workerNode =>
             workerNode.info.ready &&
             workerNode.usage.tasks.executing <
               (this.opts.tasksQueueOptions?.concurrency as number)
         ) === -1
       )
-    } else {
-      return (
-        this.workerNodes.findIndex(
-          (workerNode) =>
-            workerNode.info.ready && workerNode.usage.tasks.executing === 0
-        ) === -1
+    }
+    return (
+      this.workerNodes.findIndex(
+        workerNode =>
+          workerNode.info.ready && workerNode.usage.tasks.executing === 0
+      ) === -1
+    )
+  }
+
+  private async sendTaskFunctionOperationToWorker (
+    workerNodeKey: number,
+    message: MessageValue<Data>
+  ): Promise<boolean> {
+    return await new Promise<boolean>((resolve, reject) => {
+      const workerId = this.getWorkerInfo(workerNodeKey).id as number
+      this.registerWorkerMessageListener(workerNodeKey, message => {
+        if (
+          message.workerId === workerId &&
+          message.taskFunctionOperationStatus === true
+        ) {
+          resolve(true)
+        } else if (
+          message.workerId === workerId &&
+          message.taskFunctionOperationStatus === false
+        ) {
+          reject(
+            new Error(
+              `Task function operation ${
+                message.taskFunctionOperation as string
+              } failed on worker ${message.workerId}`
+            )
+          )
+        }
+      })
+      this.sendToWorker(workerNodeKey, message)
+    })
+  }
+
+  private async sendTaskFunctionOperationToWorkers (
+    message: MessageValue<Data>
+  ): Promise<boolean> {
+    return await new Promise<boolean>((resolve, reject) => {
+      const responsesReceived = new Array<MessageValue<Data | Response>>()
+      for (const [workerNodeKey] of this.workerNodes.entries()) {
+        this.registerWorkerMessageListener(workerNodeKey, message => {
+          if (message.taskFunctionOperationStatus != null) {
+            responsesReceived.push(message)
+            if (
+              responsesReceived.length === this.workerNodes.length &&
+              responsesReceived.every(
+                message => message.taskFunctionOperationStatus === true
+              )
+            ) {
+              resolve(true)
+            } else if (
+              responsesReceived.length === this.workerNodes.length &&
+              responsesReceived.some(
+                message => message.taskFunctionOperationStatus === false
+              )
+            ) {
+              reject(
+                new Error(
+                  `Task function operation ${
+                    message.taskFunctionOperation as string
+                  } failed on worker ${message.workerId as number}`
+                )
+              )
+            }
+          }
+        })
+        this.sendToWorker(workerNodeKey, message)
+      }
+    })
+  }
+
+  /** @inheritDoc */
+  public hasTaskFunction (name: string): boolean {
+    for (const workerNode of this.workerNodes) {
+      if (
+        Array.isArray(workerNode.info.taskFunctionNames) &&
+        workerNode.info.taskFunctionNames.includes(name)
+      ) {
+        return true
+      }
+    }
+    return false
+  }
+
+  /** @inheritDoc */
+  public async addTaskFunction (
+    name: string,
+    fn: TaskFunction<Data, Response>
+  ): Promise<boolean> {
+    if (typeof name !== 'string') {
+      throw new TypeError('name argument must be a string')
+    }
+    if (typeof name === 'string' && name.trim().length === 0) {
+      throw new TypeError('name argument must not be an empty string')
+    }
+    if (typeof fn !== 'function') {
+      throw new TypeError('fn argument must be a function')
+    }
+    const opResult = await this.sendTaskFunctionOperationToWorkers({
+      taskFunctionOperation: 'add',
+      taskFunctionName: name,
+      taskFunction: fn.toString()
+    })
+    this.taskFunctions.set(name, fn)
+    return opResult
+  }
+
+  /** @inheritDoc */
+  public async removeTaskFunction (name: string): Promise<boolean> {
+    if (!this.taskFunctions.has(name)) {
+      throw new Error(
+        'Cannot remove a task function not handled on the pool side'
       )
     }
+    const opResult = await this.sendTaskFunctionOperationToWorkers({
+      taskFunctionOperation: 'remove',
+      taskFunctionName: name
+    })
+    this.deleteTaskFunctionWorkerUsages(name)
+    this.taskFunctions.delete(name)
+    return opResult
   }
 
   /** @inheritDoc */
-  public listTaskFunctions (): string[] {
+  public listTaskFunctionNames (): string[] {
     for (const workerNode of this.workerNodes) {
       if (
-        Array.isArray(workerNode.info.taskFunctions) &&
-        workerNode.info.taskFunctions.length > 0
+        Array.isArray(workerNode.info.taskFunctionNames) &&
+        workerNode.info.taskFunctionNames.length > 0
       ) {
-        return workerNode.info.taskFunctions
+        return workerNode.info.taskFunctionNames
       }
     }
     return []
   }
 
+  /** @inheritDoc */
+  public async setDefaultTaskFunction (name: string): Promise<boolean> {
+    return await this.sendTaskFunctionOperationToWorkers({
+      taskFunctionOperation: 'default',
+      taskFunctionName: name
+    })
+  }
+
+  private deleteTaskFunctionWorkerUsages (name: string): void {
+    for (const workerNode of this.workerNodes) {
+      workerNode.deleteTaskFunctionWorkerUsage(name)
+    }
+  }
+
   private shallExecuteTask (workerNodeKey: number): boolean {
     return (
       this.tasksQueueSize(workerNodeKey) === 0 &&
@@ -749,7 +925,7 @@ export abstract class AbstractPool<
   ): Promise<Response> {
     return await new Promise<Response>((resolve, reject) => {
       if (!this.started) {
-        reject(new Error('Cannot execute a task on destroyed pool'))
+        reject(new Error('Cannot execute a task on not started pool'))
         return
       }
       if (name != null && typeof name !== 'string') {
@@ -770,14 +946,12 @@ export abstract class AbstractPool<
       }
       const timestamp = performance.now()
       const workerNodeKey = this.chooseWorkerNode()
-      const workerInfo = this.getWorkerInfo(workerNodeKey) as WorkerInfo
       const task: Task<Data> = {
         name: name ?? DEFAULT_TASK_NAME,
         // eslint-disable-next-line @typescript-eslint/consistent-type-assertions
         data: data ?? ({} as Data),
         transferList,
         timestamp,
-        workerId: workerInfo.id as number,
         taskId: randomUUID()
       }
       this.promiseResponseMap.set(task.taskId as string, {
@@ -797,6 +971,22 @@ export abstract class AbstractPool<
     })
   }
 
+  /** @inheritdoc */
+  public start (): void {
+    this.starting = true
+    while (
+      this.workerNodes.reduce(
+        (accumulator, workerNode) =>
+          !workerNode.info.dynamic ? accumulator + 1 : accumulator,
+        0
+      ) < this.numberOfWorkers
+    ) {
+      this.createAndSetupWorkerNode()
+    }
+    this.starting = false
+    this.started = true
+  }
+
   /** @inheritDoc */
   public async destroy (): Promise<void> {
     await Promise.all(
@@ -809,18 +999,23 @@ export abstract class AbstractPool<
   }
 
   protected async sendKillMessageToWorker (
-    workerNodeKey: number,
-    workerId: number
+    workerNodeKey: number
   ): Promise<void> {
     await new Promise<void>((resolve, reject) => {
-      this.registerWorkerMessageListener(workerNodeKey, (message) => {
+      this.registerWorkerMessageListener(workerNodeKey, message => {
         if (message.kill === 'success') {
           resolve()
         } else if (message.kill === 'failure') {
-          reject(new Error(`Worker ${workerId} kill message handling failed`))
+          reject(
+            new Error(
+              `Worker ${
+                message.workerId as number
+              } kill message handling failed`
+            )
+          )
         }
       })
-      this.sendToWorker(workerNodeKey, { kill: true, workerId })
+      this.sendToWorker(workerNodeKey, { kill: true })
     })
   }
 
@@ -838,7 +1033,7 @@ export abstract class AbstractPool<
    * @virtual
    */
   protected setupHook (): void {
-    /** Intentionally empty */
+    /* Intentionally empty */
   }
 
   /**
@@ -920,8 +1115,8 @@ export abstract class AbstractPool<
     const workerInfo = this.getWorkerInfo(workerNodeKey)
     return (
       workerInfo != null &&
-      Array.isArray(workerInfo.taskFunctions) &&
-      workerInfo.taskFunctions.length > 2
+      Array.isArray(workerInfo.taskFunctionNames) &&
+      workerInfo.taskFunctionNames.length > 2
     )
   }
 
@@ -936,7 +1131,7 @@ export abstract class AbstractPool<
     ) {
       --workerTaskStatistics.executing
     }
-    if (message.taskError == null) {
+    if (message.workerError == null) {
       ++workerTaskStatistics.executed
     } else {
       ++workerTaskStatistics.failed
@@ -947,7 +1142,7 @@ export abstract class AbstractPool<
     workerUsage: WorkerUsage,
     message: MessageValue<Response>
   ): void {
-    if (message.taskError != null) {
+    if (message.workerError != null) {
       return
     }
     updateMeasurementStatistics(
@@ -974,7 +1169,7 @@ export abstract class AbstractPool<
     workerUsage: WorkerUsage,
     message: MessageValue<Response>
   ): void {
-    if (message.taskError != null) {
+    if (message.workerError != null) {
       return
     }
     const eluTaskStatisticsRequirements: MeasurementStatisticsRequirements =
@@ -1062,16 +1257,16 @@ export abstract class AbstractPool<
     worker.on('online', this.opts.onlineHandler ?? EMPTY_FUNCTION)
     worker.on('message', this.opts.messageHandler ?? EMPTY_FUNCTION)
     worker.on('error', this.opts.errorHandler ?? EMPTY_FUNCTION)
-    worker.on('error', (error) => {
+    worker.on('error', error => {
       const workerNodeKey = this.getWorkerNodeKeyByWorker(worker)
-      const workerInfo = this.getWorkerInfo(workerNodeKey) as WorkerInfo
+      const workerInfo = this.getWorkerInfo(workerNodeKey)
       workerInfo.ready = false
       this.workerNodes[workerNodeKey].closeChannel()
       this.emitter?.emit(PoolEvents.error, error)
       if (
-        this.opts.restartWorkerOnError === true &&
+        this.started &&
         !this.starting &&
-        this.started
+        this.opts.restartWorkerOnError === true
       ) {
         if (workerInfo.dynamic) {
           this.createAndSetupDynamicWorkerNode()
@@ -1079,7 +1274,7 @@ export abstract class AbstractPool<
           this.createAndSetupWorkerNode()
         }
       }
-      if (this.opts.enableTasksQueue === true) {
+      if (this.started && this.opts.enableTasksQueue === true) {
         this.redistributeQueuedTasks(workerNodeKey)
       }
     })
@@ -1102,7 +1297,7 @@ export abstract class AbstractPool<
    */
   protected createAndSetupDynamicWorkerNode (): number {
     const workerNodeKey = this.createAndSetupWorkerNode()
-    this.registerWorkerMessageListener(workerNodeKey, (message) => {
+    this.registerWorkerMessageListener(workerNodeKey, message => {
       const localWorkerNodeKey = this.getWorkerNodeKeyByWorkerId(
         message.workerId
       )
@@ -1117,16 +1312,26 @@ export abstract class AbstractPool<
               workerUsage.tasks.executing === 0 &&
               this.tasksQueueSize(localWorkerNodeKey) === 0)))
       ) {
-        this.destroyWorkerNode(localWorkerNodeKey).catch((error) => {
+        this.destroyWorkerNode(localWorkerNodeKey).catch(error => {
           this.emitter?.emit(PoolEvents.error, error)
         })
       }
     })
-    const workerInfo = this.getWorkerInfo(workerNodeKey) as WorkerInfo
+    const workerInfo = this.getWorkerInfo(workerNodeKey)
     this.sendToWorker(workerNodeKey, {
-      checkActive: true,
-      workerId: workerInfo.id as number
+      checkActive: true
     })
+    if (this.taskFunctions.size > 0) {
+      for (const [taskFunctionName, taskFunction] of this.taskFunctions) {
+        this.sendTaskFunctionOperationToWorker(workerNodeKey, {
+          taskFunctionOperation: 'add',
+          taskFunctionName,
+          taskFunction: taskFunction.toString()
+        }).catch(error => {
+          this.emitter?.emit(PoolEvents.error, error)
+        })
+      }
+    }
     workerInfo.dynamic = true
     if (
       this.workerChoiceStrategyContext.getStrategyPolicy().dynamicWorkerReady ||
@@ -1165,10 +1370,14 @@ export abstract class AbstractPool<
     // Send the statistics message to worker.
     this.sendStatisticsMessageToWorker(workerNodeKey)
     if (this.opts.enableTasksQueue === true) {
-      this.workerNodes[workerNodeKey].onEmptyQueue =
-        this.taskStealingOnEmptyQueue.bind(this)
-      this.workerNodes[workerNodeKey].onBackPressure =
-        this.tasksStealingOnBackPressure.bind(this)
+      if (this.opts.tasksQueueOptions?.taskStealing === true) {
+        this.workerNodes[workerNodeKey].onEmptyQueue =
+          this.taskStealingOnEmptyQueue.bind(this)
+      }
+      if (this.opts.tasksQueueOptions?.tasksStealingOnBackPressure === true) {
+        this.workerNodes[workerNodeKey].onBackPressure =
+          this.tasksStealingOnBackPressure.bind(this)
+      }
     }
   }
 
@@ -1192,38 +1401,27 @@ export abstract class AbstractPool<
             .runTime.aggregate,
         elu: this.workerChoiceStrategyContext.getTaskStatisticsRequirements()
           .elu.aggregate
-      },
-      workerId: (this.getWorkerInfo(workerNodeKey) as WorkerInfo).id as number
+      }
     })
   }
 
   private redistributeQueuedTasks (workerNodeKey: number): void {
     while (this.tasksQueueSize(workerNodeKey) > 0) {
-      let destinationWorkerNodeKey!: number
-      let minQueuedTasks = Infinity
-      for (const [workerNodeId, workerNode] of this.workerNodes.entries()) {
-        if (workerNode.info.ready && workerNodeId !== workerNodeKey) {
-          if (workerNode.usage.tasks.queued === 0) {
-            destinationWorkerNodeKey = workerNodeId
-            break
-          }
-          if (workerNode.usage.tasks.queued < minQueuedTasks) {
-            minQueuedTasks = workerNode.usage.tasks.queued
-            destinationWorkerNodeKey = workerNodeId
-          }
-        }
-      }
-      if (destinationWorkerNodeKey != null) {
-        const destinationWorkerNode = this.workerNodes[destinationWorkerNodeKey]
-        const task = {
-          ...(this.dequeueTask(workerNodeKey) as Task<Data>),
-          workerId: destinationWorkerNode.info.id as number
-        }
-        if (this.shallExecuteTask(destinationWorkerNodeKey)) {
-          this.executeTask(destinationWorkerNodeKey, task)
-        } else {
-          this.enqueueTask(destinationWorkerNodeKey, task)
-        }
+      const destinationWorkerNodeKey = this.workerNodes.reduce(
+        (minWorkerNodeKey, workerNode, workerNodeKey, workerNodes) => {
+          return workerNode.info.ready &&
+            workerNode.usage.tasks.queued <
+              workerNodes[minWorkerNodeKey].usage.tasks.queued
+            ? workerNodeKey
+            : minWorkerNodeKey
+        },
+        0
+      )
+      const task = this.dequeueTask(workerNodeKey) as Task<Data>
+      if (this.shallExecuteTask(destinationWorkerNodeKey)) {
+        this.executeTask(destinationWorkerNodeKey, task)
+      } else {
+        this.enqueueTask(destinationWorkerNodeKey, task)
       }
     }
   }
@@ -1249,42 +1447,35 @@ export abstract class AbstractPool<
 
   private taskStealingOnEmptyQueue (workerId: number): void {
     const destinationWorkerNodeKey = this.getWorkerNodeKeyByWorkerId(workerId)
-    const destinationWorkerNode = this.workerNodes[destinationWorkerNodeKey]
     const workerNodes = this.workerNodes
       .slice()
       .sort(
         (workerNodeA, workerNodeB) =>
           workerNodeB.usage.tasks.queued - workerNodeA.usage.tasks.queued
       )
-    for (const sourceWorkerNode of workerNodes) {
-      if (sourceWorkerNode.usage.tasks.queued === 0) {
-        break
-      }
-      if (
-        sourceWorkerNode.info.ready &&
-        sourceWorkerNode.info.id !== workerId &&
-        sourceWorkerNode.usage.tasks.queued > 0
-      ) {
-        const task = {
-          ...(sourceWorkerNode.popTask() as Task<Data>),
-          workerId: destinationWorkerNode.info.id as number
-        }
-        if (this.shallExecuteTask(destinationWorkerNodeKey)) {
-          this.executeTask(destinationWorkerNodeKey, task)
-        } else {
-          this.enqueueTask(destinationWorkerNodeKey, task)
-        }
-        this.updateTaskStolenStatisticsWorkerUsage(
-          destinationWorkerNodeKey,
-          task.name as string
-        )
-        break
+    const sourceWorkerNode = workerNodes.find(
+      workerNode =>
+        workerNode.info.ready &&
+        workerNode.info.id !== workerId &&
+        workerNode.usage.tasks.queued > 0
+    )
+    if (sourceWorkerNode != null) {
+      const task = sourceWorkerNode.popTask() as Task<Data>
+      if (this.shallExecuteTask(destinationWorkerNodeKey)) {
+        this.executeTask(destinationWorkerNodeKey, task)
+      } else {
+        this.enqueueTask(destinationWorkerNodeKey, task)
       }
+      this.updateTaskStolenStatisticsWorkerUsage(
+        destinationWorkerNodeKey,
+        task.name as string
+      )
     }
   }
 
   private tasksStealingOnBackPressure (workerId: number): void {
-    if ((this.opts.tasksQueueOptions?.size as number) <= 1) {
+    const sizeOffset = 1
+    if ((this.opts.tasksQueueOptions?.size as number) <= sizeOffset) {
       return
     }
     const sourceWorkerNode =
@@ -1301,12 +1492,9 @@ export abstract class AbstractPool<
         workerNode.info.ready &&
         workerNode.info.id !== workerId &&
         workerNode.usage.tasks.queued <
-          (this.opts.tasksQueueOptions?.size as number) - 1
+          (this.opts.tasksQueueOptions?.size as number) - sizeOffset
       ) {
-        const task = {
-          ...(sourceWorkerNode.popTask() as Task<Data>),
-          workerId: workerNode.info.id as number
-        }
+        const task = sourceWorkerNode.popTask() as Task<Data>
         if (this.shallExecuteTask(workerNodeKey)) {
           this.executeTask(workerNodeKey, task)
         } else {
@@ -1326,51 +1514,52 @@ export abstract class AbstractPool<
    * @returns The listener function to execute when a message is received from a worker.
    */
   protected workerListener (): (message: MessageValue<Response>) => void {
-    return (message) => {
+    return message => {
       this.checkMessageWorkerId(message)
-      if (message.ready != null && message.taskFunctions != null) {
+      if (message.ready != null && message.taskFunctionNames != null) {
         // Worker ready response received from worker
         this.handleWorkerReadyResponse(message)
       } else if (message.taskId != null) {
         // Task execution response received from worker
         this.handleTaskExecutionResponse(message)
-      } else if (message.taskFunctions != null) {
-        // Task functions message received from worker
-        (
-          this.getWorkerInfo(
-            this.getWorkerNodeKeyByWorkerId(message.workerId)
-          ) as WorkerInfo
-        ).taskFunctions = message.taskFunctions
+      } else if (message.taskFunctionNames != null) {
+        // Task function names message received from worker
+        this.getWorkerInfo(
+          this.getWorkerNodeKeyByWorkerId(message.workerId)
+        ).taskFunctionNames = message.taskFunctionNames
       }
     }
   }
 
   private handleWorkerReadyResponse (message: MessageValue<Response>): void {
     if (message.ready === false) {
-      throw new Error(`Worker ${message.workerId} failed to initialize`)
+      throw new Error(
+        `Worker ${message.workerId as number} failed to initialize`
+      )
     }
     const workerInfo = this.getWorkerInfo(
       this.getWorkerNodeKeyByWorkerId(message.workerId)
-    ) as WorkerInfo
+    )
     workerInfo.ready = message.ready as boolean
-    workerInfo.taskFunctions = message.taskFunctions
-    if (this.emitter != null && this.ready) {
-      this.emitter.emit(PoolEvents.ready, this.info)
+    workerInfo.taskFunctionNames = message.taskFunctionNames
+    if (this.ready) {
+      this.emitter?.emit(PoolEvents.ready, this.info)
     }
   }
 
   private handleTaskExecutionResponse (message: MessageValue<Response>): void {
-    const { taskId, taskError, data } = message
+    const { taskId, workerError, data } = message
     const promiseResponse = this.promiseResponseMap.get(taskId as string)
     if (promiseResponse != null) {
-      if (taskError != null) {
-        this.emitter?.emit(PoolEvents.taskError, taskError)
-        promiseResponse.reject(taskError.message)
+      if (workerError != null) {
+        this.emitter?.emit(PoolEvents.taskError, workerError)
+        promiseResponse.reject(workerError.message)
       } else {
         promiseResponse.resolve(data as Response)
       }
       const workerNodeKey = promiseResponse.workerNodeKey
       this.afterTaskExecutionHook(workerNodeKey, message)
+      this.workerChoiceStrategyContext.update(workerNodeKey)
       this.promiseResponseMap.delete(taskId as string)
       if (
         this.opts.enableTasksQueue === true &&
@@ -1383,7 +1572,6 @@ export abstract class AbstractPool<
           this.dequeueTask(workerNodeKey) as Task<Data>
         )
       }
-      this.workerChoiceStrategyContext.update(workerNodeKey)
     }
   }
 
@@ -1413,8 +1601,8 @@ export abstract class AbstractPool<
    * @param workerNodeKey - The worker node key.
    * @returns The worker information.
    */
-  protected getWorkerInfo (workerNodeKey: number): WorkerInfo | undefined {
-    return this.workerNodes[workerNodeKey]?.info
+  protected getWorkerInfo (workerNodeKey: number): WorkerInfo {
+    return this.workerNodes[workerNodeKey].info
   }
 
   /**
@@ -1436,7 +1624,7 @@ export abstract class AbstractPool<
     this.workerNodes.push(workerNode)
     const workerNodeKey = this.getWorkerNodeKeyByWorker(worker)
     if (workerNodeKey === -1) {
-      throw new Error('Worker node added not found')
+      throw new Error('Worker added not found in worker nodes')
     }
     return workerNodeKey
   }
@@ -1466,7 +1654,7 @@ export abstract class AbstractPool<
     return (
       this.opts.enableTasksQueue === true &&
       this.workerNodes.findIndex(
-        (workerNode) => !workerNode.hasBackPressure()
+        workerNode => !workerNode.hasBackPressure()
       ) === -1
     )
   }