feat: introduce worker node queue back pressure detection
[poolifier.git] / src / pools / abstract-pool.ts
index aec731a5c189903b46230ceceeb831768fa62425..eb2c2f7818a687ac8f8016eb27489895cadfaaee 100644 (file)
@@ -1,6 +1,7 @@
 import { randomUUID } from 'node:crypto'
 import { performance } from 'node:perf_hooks'
 import { existsSync } from 'node:fs'
+import { type TransferListItem } from 'node:worker_threads'
 import type {
   MessageValue,
   PromiseResponseWrapper,
@@ -105,7 +106,9 @@ export abstract class AbstractPool<
     protected readonly opts: PoolOptions<Worker>
   ) {
     if (!this.isMain()) {
-      throw new Error('Cannot start a pool from a worker!')
+      throw new Error(
+        'Cannot start a pool from a worker with the same type as the pool'
+      )
     }
     this.checkNumberOfWorkers(this.numberOfWorkers)
     this.checkFilePath(this.filePath)
@@ -359,14 +362,14 @@ export abstract class AbstractPool<
           minimum: round(
             Math.min(
               ...this.workerNodes.map(
-                workerNode => workerNode.usage.runTime?.minimum ?? Infinity
+                (workerNode) => workerNode.usage.runTime?.minimum ?? Infinity
               )
             )
           ),
           maximum: round(
             Math.max(
               ...this.workerNodes.map(
-                workerNode => workerNode.usage.runTime?.maximum ?? -Infinity
+                (workerNode) => workerNode.usage.runTime?.maximum ?? -Infinity
               )
             )
           ),
@@ -387,7 +390,7 @@ export abstract class AbstractPool<
             median: round(
               median(
                 this.workerNodes.map(
-                  workerNode => workerNode.usage.runTime?.median ?? 0
+                  (workerNode) => workerNode.usage.runTime?.median ?? 0
                 )
               )
             )
@@ -400,14 +403,14 @@ export abstract class AbstractPool<
           minimum: round(
             Math.min(
               ...this.workerNodes.map(
-                workerNode => workerNode.usage.waitTime?.minimum ?? Infinity
+                (workerNode) => workerNode.usage.waitTime?.minimum ?? Infinity
               )
             )
           ),
           maximum: round(
             Math.max(
               ...this.workerNodes.map(
-                workerNode => workerNode.usage.waitTime?.maximum ?? -Infinity
+                (workerNode) => workerNode.usage.waitTime?.maximum ?? -Infinity
               )
             )
           ),
@@ -428,7 +431,7 @@ export abstract class AbstractPool<
             median: round(
               median(
                 this.workerNodes.map(
-                  workerNode => workerNode.usage.waitTime?.median ?? 0
+                  (workerNode) => workerNode.usage.waitTime?.median ?? 0
                 )
               )
             )
@@ -503,7 +506,9 @@ export abstract class AbstractPool<
    * @throws {@link https://nodejs.org/api/errors.html#class-error} If the worker id is invalid.
    */
   private checkMessageWorkerId (message: MessageValue<Response>): void {
-    if (
+    if (message.workerId == null) {
+      throw new Error('Worker message received without worker id')
+    } else if (
       message.workerId != null &&
       this.getWorkerNodeKeyByWorkerId(message.workerId) === -1
     ) {
@@ -521,7 +526,7 @@ export abstract class AbstractPool<
    */
   private getWorkerNodeKeyByWorker (worker: Worker): number {
     return this.workerNodes.findIndex(
-      workerNode => workerNode.worker === worker
+      (workerNode) => workerNode.worker === worker
     )
   }
 
@@ -533,7 +538,7 @@ export abstract class AbstractPool<
    */
   private getWorkerNodeKeyByWorkerId (workerId: number): number {
     return this.workerNodes.findIndex(
-      workerNode => workerNode.info.id === workerId
+      (workerNode) => workerNode.info.id === workerId
     )
   }
 
@@ -552,7 +557,7 @@ export abstract class AbstractPool<
     }
     for (const [workerNodeKey, workerNode] of this.workerNodes.entries()) {
       workerNode.resetUsage()
-      this.sendWorkerStatisticsMessageToWorker(workerNodeKey)
+      this.sendStatisticsMessageToWorker(workerNodeKey)
     }
   }
 
@@ -615,30 +620,82 @@ export abstract class AbstractPool<
   protected abstract get busy (): boolean
 
   /**
-   * Whether worker nodes are executing at least one task.
+   * Whether worker nodes are executing concurrently their tasks quota or not.
    *
    * @returns Worker nodes busyness boolean status.
    */
   protected internalBusy (): boolean {
-    return (
-      this.workerNodes.findIndex(
-        workerNode =>
-          workerNode.info.ready && workerNode.usage.tasks.executing === 0
-      ) === -1
-    )
+    if (this.opts.enableTasksQueue === true) {
+      return (
+        this.workerNodes.findIndex(
+          (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
+      )
+    }
+  }
+
+  /** @inheritDoc */
+  public listTaskFunctions (): string[] {
+    for (const workerNode of this.workerNodes) {
+      if (
+        Array.isArray(workerNode.info.taskFunctions) &&
+        workerNode.info.taskFunctions.length > 0
+      ) {
+        return workerNode.info.taskFunctions
+      }
+    }
+    return []
   }
 
   /** @inheritDoc */
-  public async execute (data?: Data, name?: string): Promise<Response> {
+  public async execute (
+    data?: Data,
+    name?: string,
+    transferList?: TransferListItem[]
+  ): Promise<Response> {
     return await new Promise<Response>((resolve, reject) => {
+      if (name != null && typeof name !== 'string') {
+        reject(new TypeError('name argument must be a string'))
+      }
+      if (
+        name != null &&
+        typeof name === 'string' &&
+        name.trim().length === 0
+      ) {
+        reject(new TypeError('name argument must not be an empty string'))
+      }
+      if (transferList != null && !Array.isArray(transferList)) {
+        reject(new TypeError('transferList argument must be an array'))
+      }
       const timestamp = performance.now()
       const workerNodeKey = this.chooseWorkerNode()
+      const workerInfo = this.getWorkerInfo(workerNodeKey)
+      if (
+        name != null &&
+        Array.isArray(workerInfo.taskFunctions) &&
+        !workerInfo.taskFunctions.includes(name)
+      ) {
+        reject(
+          new Error(`Task function '${name}' is not registered in the pool`)
+        )
+      }
       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: this.getWorkerInfo(workerNodeKey).id as number,
+        workerId: workerInfo.id as number,
         taskId: randomUUID()
       }
       this.promiseResponseMap.set(task.taskId as string, {
@@ -667,6 +724,23 @@ export abstract class AbstractPool<
         await this.destroyWorkerNode(workerNodeKey)
       })
     )
+    this.emitter?.emit(PoolEvents.destroy)
+  }
+
+  protected async sendKillMessageToWorker (
+    workerNodeKey: number,
+    workerId: number
+  ): Promise<void> {
+    await new Promise<void>((resolve, reject) => {
+      this.registerWorkerMessageListener(workerNodeKey, (message) => {
+        if (message.kill === 'success') {
+          resolve()
+        } else if (message.kill === 'failure') {
+          reject(new Error(`Worker ${workerId} kill message handling failed`))
+        }
+      })
+      this.sendToWorker(workerNodeKey, { kill: true, workerId })
+    })
   }
 
   /**
@@ -705,11 +779,13 @@ export abstract class AbstractPool<
     const workerUsage = this.workerNodes[workerNodeKey].usage
     ++workerUsage.tasks.executing
     this.updateWaitTimeWorkerUsage(workerUsage, task)
-    const taskWorkerUsage = this.workerNodes[workerNodeKey].getTaskWorkerUsage(
-      task.name as string
-    ) as WorkerUsage
-    ++taskWorkerUsage.tasks.executing
-    this.updateWaitTimeWorkerUsage(taskWorkerUsage, task)
+    if (this.canUpdateTaskWorkerUsage(workerNodeKey)) {
+      const taskWorkerUsage = this.workerNodes[
+        workerNodeKey
+      ].getTaskWorkerUsage(task.name as string) as WorkerUsage
+      ++taskWorkerUsage.tasks.executing
+      this.updateWaitTimeWorkerUsage(taskWorkerUsage, task)
+    }
   }
 
   /**
@@ -727,12 +803,24 @@ export abstract class AbstractPool<
     this.updateTaskStatisticsWorkerUsage(workerUsage, message)
     this.updateRunTimeWorkerUsage(workerUsage, message)
     this.updateEluWorkerUsage(workerUsage, message)
-    const taskWorkerUsage = this.workerNodes[workerNodeKey].getTaskWorkerUsage(
-      message.taskPerformance?.name ?? DEFAULT_TASK_NAME
-    ) as WorkerUsage
-    this.updateTaskStatisticsWorkerUsage(taskWorkerUsage, message)
-    this.updateRunTimeWorkerUsage(taskWorkerUsage, message)
-    this.updateEluWorkerUsage(taskWorkerUsage, message)
+    if (this.canUpdateTaskWorkerUsage(workerNodeKey)) {
+      const taskWorkerUsage = this.workerNodes[
+        workerNodeKey
+      ].getTaskWorkerUsage(
+        message.taskPerformance?.name ?? DEFAULT_TASK_NAME
+      ) as WorkerUsage
+      this.updateTaskStatisticsWorkerUsage(taskWorkerUsage, message)
+      this.updateRunTimeWorkerUsage(taskWorkerUsage, message)
+      this.updateEluWorkerUsage(taskWorkerUsage, message)
+    }
+  }
+
+  private canUpdateTaskWorkerUsage (workerNodeKey: number): boolean {
+    const workerInfo = this.getWorkerInfo(workerNodeKey)
+    return (
+      Array.isArray(workerInfo.taskFunctions) &&
+      workerInfo.taskFunctions.length > 1
+    )
   }
 
   private updateTaskStatisticsWorkerUsage (
@@ -839,10 +927,12 @@ export abstract class AbstractPool<
    *
    * @param workerNodeKey - The worker node key.
    * @param message - The message.
+   * @param transferList - The optional array of transferable objects.
    */
   protected abstract sendToWorker (
     workerNodeKey: number,
-    message: MessageValue<Data>
+    message: MessageValue<Data>,
+    transferList?: TransferListItem[]
   ): void
 
   /**
@@ -860,9 +950,10 @@ export abstract class AbstractPool<
   protected createAndSetupWorkerNode (): number {
     const worker = this.createWorker()
 
+    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)
       workerInfo.ready = false
@@ -879,7 +970,6 @@ export abstract class AbstractPool<
         this.redistributeQueuedTasks(workerNodeKey)
       }
     })
-    worker.on('online', this.opts.onlineHandler ?? EMPTY_FUNCTION)
     worker.on('exit', this.opts.exitHandler ?? EMPTY_FUNCTION)
     worker.once('exit', () => {
       this.removeWorkerNode(worker)
@@ -899,7 +989,7 @@ 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
       )
@@ -907,14 +997,16 @@ export abstract class AbstractPool<
       // Kill message received from worker
       if (
         isKillBehavior(KillBehaviors.HARD, message.kill) ||
-        (message.kill != null &&
+        (isKillBehavior(KillBehaviors.SOFT, message.kill) &&
           ((this.opts.enableTasksQueue === false &&
             workerUsage.tasks.executing === 0) ||
             (this.opts.enableTasksQueue === true &&
               workerUsage.tasks.executing === 0 &&
               this.tasksQueueSize(localWorkerNodeKey) === 0)))
       ) {
-        this.destroyWorkerNode(localWorkerNodeKey).catch(EMPTY_FUNCTION)
+        this.destroyWorkerNode(localWorkerNodeKey).catch((error) => {
+          this.emitter?.emit(PoolEvents.error, error)
+        })
       }
     })
     const workerInfo = this.getWorkerInfo(workerNodeKey)
@@ -953,8 +1045,8 @@ export abstract class AbstractPool<
     this.registerWorkerMessageListener(workerNodeKey, this.workerListener())
     // Send the startup message to worker.
     this.sendStartupMessageToWorker(workerNodeKey)
-    // Send the worker statistics message to worker.
-    this.sendWorkerStatisticsMessageToWorker(workerNodeKey)
+    // Send the statistics message to worker.
+    this.sendStatisticsMessageToWorker(workerNodeKey)
   }
 
   /**
@@ -965,11 +1057,11 @@ export abstract class AbstractPool<
   protected abstract sendStartupMessageToWorker (workerNodeKey: number): void
 
   /**
-   * Sends the worker statistics message to worker given its worker node key.
+   * Sends the statistics message to worker given its worker node key.
    *
    * @param workerNodeKey - The worker node key.
    */
-  private sendWorkerStatisticsMessageToWorker (workerNodeKey: number): void {
+  private sendStatisticsMessageToWorker (workerNodeKey: number): void {
     this.sendToWorker(workerNodeKey, {
       statistics: {
         runTime:
@@ -1032,41 +1124,50 @@ 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) {
+      if (message.ready != null && message.taskFunctions != 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)
+        ).taskFunctions = message.taskFunctions
       }
     }
   }
 
   private handleWorkerReadyResponse (message: MessageValue<Response>): void {
-    this.getWorkerInfo(
+    if (message.ready === false) {
+      throw new Error(`Worker ${message.workerId} failed to initialize`)
+    }
+    const workerInfo = this.getWorkerInfo(
       this.getWorkerNodeKeyByWorkerId(message.workerId)
-    ).ready = message.ready as boolean
+    )
+    workerInfo.ready = message.ready as boolean
+    workerInfo.taskFunctions = message.taskFunctions
     if (this.emitter != null && this.ready) {
       this.emitter.emit(PoolEvents.ready, this.info)
     }
   }
 
   private handleTaskExecutionResponse (message: MessageValue<Response>): void {
-    const promiseResponse = this.promiseResponseMap.get(
-      message.taskId as string
-    )
+    const { taskId, taskError, data } = message
+    const promiseResponse = this.promiseResponseMap.get(taskId as string)
     if (promiseResponse != null) {
-      if (message.taskError != null) {
-        this.emitter?.emit(PoolEvents.taskError, message.taskError)
-        promiseResponse.reject(message.taskError.message)
+      if (taskError != null) {
+        this.emitter?.emit(PoolEvents.taskError, taskError)
+        promiseResponse.reject(taskError.message)
       } else {
-        promiseResponse.resolve(message.data as Response)
+        promiseResponse.resolve(data as Response)
       }
       const workerNodeKey = promiseResponse.workerNodeKey
       this.afterTaskExecutionHook(workerNodeKey, message)
-      this.promiseResponseMap.delete(message.taskId as string)
+      this.promiseResponseMap.delete(taskId as string)
       if (
         this.opts.enableTasksQueue === true &&
         this.tasksQueueSize(workerNodeKey) > 0 &&
@@ -1111,7 +1212,11 @@ export abstract class AbstractPool<
    * @throws {@link https://nodejs.org/api/errors.html#class-error} If the added worker node is not found.
    */
   private addWorkerNode (worker: Worker): number {
-    const workerNode = new WorkerNode<Worker, Data>(worker, this.worker)
+    const workerNode = new WorkerNode<Worker, Data>(
+      worker,
+      this.worker,
+      this.maxSize
+    )
     // Flag the worker node as ready at pool startup.
     if (this.starting) {
       workerNode.info.ready = true
@@ -1119,7 +1224,7 @@ export abstract class AbstractPool<
     this.workerNodes.push(workerNode)
     const workerNodeKey = this.getWorkerNodeKeyByWorker(worker)
     if (workerNodeKey === -1) {
-      throw new Error('Worker node not found')
+      throw new Error('Worker node added not found')
     }
     return workerNodeKey
   }
@@ -1145,10 +1250,19 @@ export abstract class AbstractPool<
    */
   private executeTask (workerNodeKey: number, task: Task<Data>): void {
     this.beforeTaskExecutionHook(workerNodeKey, task)
-    this.sendToWorker(workerNodeKey, task)
+    this.sendToWorker(workerNodeKey, task, task.transferList)
   }
 
   private enqueueTask (workerNodeKey: number, task: Task<Data>): number {
+    if (
+      this.opts.enableTasksQueue === true &&
+      this.workerNodes[workerNodeKey].hasBackPressure()
+    ) {
+      this.emitter?.emit(PoolEvents.backPressure, {
+        workerId: this.getWorkerInfo(workerNodeKey).id,
+        ...this.info
+      })
+    }
     return this.workerNodes[workerNodeKey].enqueueTask(task)
   }