fix: ensure the task concurrency is respected at queued task
[poolifier.git] / src / pools / abstract-pool.ts
index 00bfaf8eea87f991221664e7cea3059cca4f5457..0d3d21832a715191e6efad9723c6a47454ae2215 100644 (file)
@@ -10,6 +10,7 @@ import {
   DEFAULT_TASK_NAME,
   DEFAULT_WORKER_CHOICE_STRATEGY_OPTIONS,
   EMPTY_FUNCTION,
+  isAsyncFunction,
   isKillBehavior,
   isPlainObject,
   median,
@@ -114,6 +115,7 @@ export abstract class AbstractPool<
     this.chooseWorkerNode = this.chooseWorkerNode.bind(this)
     this.executeTask = this.executeTask.bind(this)
     this.enqueueTask = this.enqueueTask.bind(this)
+    this.dequeueTask = this.dequeueTask.bind(this)
     this.checkAndEmitEvents = this.checkAndEmitEvents.bind(this)
 
     if (this.opts.enableEvents === true) {
@@ -171,7 +173,15 @@ export abstract class AbstractPool<
 
   protected checkDynamicPoolSize (min: number, max: number): void {
     if (this.type === PoolTypes.dynamic) {
-      if (min > max) {
+      if (max == null) {
+        throw new Error(
+          'Cannot instantiate a dynamic pool without specifying the maximum pool size'
+        )
+      } else if (!Number.isSafeInteger(max)) {
+        throw new TypeError(
+          'Cannot instantiate a dynamic pool with a non safe integer maximum pool size'
+        )
+      } else if (min > max) {
         throw new RangeError(
           'Cannot instantiate a dynamic pool with a maximum pool size inferior to the minimum pool size'
         )
@@ -284,7 +294,7 @@ export abstract class AbstractPool<
         0
       ) < this.numberOfWorkers
     ) {
-      this.createAndSetupWorker()
+      this.createAndSetupWorkerNode()
     }
   }
 
@@ -425,6 +435,9 @@ export abstract class AbstractPool<
     }
   }
 
+  /**
+   * The pool readiness boolean status.
+   */
   private get ready (): boolean {
     return (
       this.workerNodes.reduce(
@@ -438,7 +451,7 @@ export abstract class AbstractPool<
   }
 
   /**
-   * Gets the approximate pool utilization.
+   * The approximate pool utilization.
    *
    * @returns The pool utilization.
    */
@@ -459,38 +472,27 @@ export abstract class AbstractPool<
   }
 
   /**
-   * Pool type.
+   * The pool type.
    *
    * If it is `'dynamic'`, it provides the `max` property.
    */
   protected abstract get type (): PoolType
 
   /**
-   * Gets the worker type.
+   * The worker type.
    */
   protected abstract get worker (): WorkerType
 
   /**
-   * Pool minimum size.
+   * The pool minimum size.
    */
   protected abstract get minSize (): number
 
   /**
-   * Pool maximum size.
+   * The pool maximum size.
    */
   protected abstract get maxSize (): number
 
-  /**
-   * Get the worker given its id.
-   *
-   * @param workerId - The worker id.
-   * @returns The worker if found in the pool worker nodes, `undefined` otherwise.
-   */
-  private getWorkerById (workerId: number): Worker | undefined {
-    return this.workerNodes.find(workerNode => workerNode.info.id === workerId)
-      ?.worker
-  }
-
   /**
    * Checks if the worker id sent in the received message from a worker is valid.
    *
@@ -500,7 +502,7 @@ export abstract class AbstractPool<
   private checkMessageWorkerId (message: MessageValue<Response>): void {
     if (
       message.workerId != null &&
-      this.getWorkerById(message.workerId) == null
+      this.getWorkerNodeKeyByWorkerId(message.workerId) == null
     ) {
       throw new Error(
         `Worker message received from unknown worker '${message.workerId}'`
@@ -514,12 +516,26 @@ export abstract class AbstractPool<
    * @param worker - The worker.
    * @returns The worker node key if found in the pool worker nodes, `-1` otherwise.
    */
-  protected getWorkerNodeKey (worker: Worker): number {
+  private getWorkerNodeKey (worker: Worker): number {
     return this.workerNodes.findIndex(
       workerNode => workerNode.worker === worker
     )
   }
 
+  /**
+   * Gets the worker node key given its worker id.
+   *
+   * @param workerId - The worker id.
+   * @returns The worker node key if the worker id is found in the pool worker nodes, `undefined` otherwise.
+   */
+  private getWorkerNodeKeyByWorkerId (workerId: number): number | undefined {
+    for (const [workerNodeKey, workerNode] of this.workerNodes.entries()) {
+      if (workerNode.info.id === workerId) {
+        return workerNodeKey
+      }
+    }
+  }
+
   /** @inheritDoc */
   public setWorkerChoiceStrategy (
     workerChoiceStrategy: WorkerChoiceStrategy,
@@ -533,9 +549,9 @@ export abstract class AbstractPool<
     if (workerChoiceStrategyOptions != null) {
       this.setWorkerChoiceStrategyOptions(workerChoiceStrategyOptions)
     }
-    for (const workerNode of this.workerNodes) {
+    for (const [workerNodeKey, workerNode] of this.workerNodes.entries()) {
       workerNode.resetUsage()
-      this.setWorkerStatistics(workerNode.worker)
+      this.sendWorkerStatisticsMessageToWorker(workerNodeKey)
     }
   }
 
@@ -654,18 +670,20 @@ export abstract class AbstractPool<
             resolve()
           })
         })
-        await this.destroyWorker(workerNode.worker)
+        await this.destroyWorkerNode(workerNodeKey)
         await workerExitPromise
       })
     )
   }
 
   /**
-   * Terminates the given worker.
+   * Terminates the worker node given its worker node key.
    *
-   * @param worker - A worker within `workerNodes`.
+   * @param workerNodeKey - The worker node key.
    */
-  protected abstract destroyWorker (worker: Worker): void | Promise<void>
+  protected abstract destroyWorkerNode (
+    workerNodeKey: number
+  ): void | Promise<void>
 
   /**
    * Setup hook to execute code before worker nodes are created in the abstract constructor.
@@ -802,15 +820,15 @@ export abstract class AbstractPool<
    *
    * The default worker choice strategy uses a round robin algorithm to distribute the tasks.
    *
-   * @returns The worker node key
+   * @returns The chosen worker node key
    */
   private chooseWorkerNode (): number {
     if (this.shallCreateDynamicWorker()) {
-      const worker = this.createAndSetupDynamicWorker()
+      const workerNodeKey = this.createAndSetupDynamicWorkerNode()
       if (
         this.workerChoiceStrategyContext.getStrategyPolicy().useDynamicWorker
       ) {
-        return this.getWorkerNodeKey(worker)
+        return workerNodeKey
       }
     }
     return this.workerChoiceStrategyContext.execute()
@@ -826,13 +844,13 @@ export abstract class AbstractPool<
   }
 
   /**
-   * Sends a message to the given worker.
+   * Sends a message to worker given its worker node key.
    *
-   * @param worker - The worker which should receive the message.
+   * @param workerNodeKey - The worker node key.
    * @param message - The message.
    */
   protected abstract sendToWorker (
-    worker: Worker,
+    workerNodeKey: number,
     message: MessageValue<Data>
   ): void
 
@@ -844,11 +862,11 @@ export abstract class AbstractPool<
   protected abstract createWorker (): Worker
 
   /**
-   * Creates a new worker and sets it up completely in the pool worker nodes.
+   * Creates a new, completely set up worker node.
    *
-   * @returns New, completely set up worker.
+   * @returns New, completely set up worker node key.
    */
-  protected createAndSetupWorker (): Worker {
+  protected createAndSetupWorkerNode (): number {
     const worker = this.createWorker()
 
     worker.on('message', this.opts.messageHandler ?? EMPTY_FUNCTION)
@@ -861,9 +879,9 @@ export abstract class AbstractPool<
       this.emitter?.emit(PoolEvents.error, error)
       if (this.opts.restartWorkerOnError === true && !this.starting) {
         if (workerInfo.dynamic) {
-          this.createAndSetupDynamicWorker()
+          this.createAndSetupDynamicWorkerNode()
         } else {
-          this.createAndSetupWorker()
+          this.createAndSetupWorkerNode()
         }
       }
       if (this.opts.enableTasksQueue === true) {
@@ -876,83 +894,117 @@ export abstract class AbstractPool<
       this.removeWorkerNode(worker)
     })
 
-    this.addWorkerNode(worker)
+    const workerNodeKey = this.addWorkerNode(worker)
 
-    this.afterWorkerSetup(worker)
+    this.afterWorkerNodeSetup(workerNodeKey)
 
-    return worker
+    return workerNodeKey
   }
 
   /**
-   * Creates a new dynamic worker and sets it up completely in the pool worker nodes.
+   * Creates a new, completely set up dynamic worker node.
    *
-   * @returns New, completely set up dynamic worker.
+   * @returns New, completely set up dynamic worker node key.
    */
-  protected createAndSetupDynamicWorker (): Worker {
-    const worker = this.createAndSetupWorker()
-    this.registerWorkerMessageListener(worker, message => {
-      const workerNodeKey = this.getWorkerNodeKey(worker)
+  protected createAndSetupDynamicWorkerNode (): number {
+    const workerNodeKey = this.createAndSetupWorkerNode()
+    this.registerWorkerMessageListener(workerNodeKey, message => {
+      const localWorkerNodeKey = this.getWorkerNodeKeyByWorkerId(
+        message.workerId
+      ) as number
+      const workerUsage = this.workerNodes[localWorkerNodeKey].usage
       if (
         isKillBehavior(KillBehaviors.HARD, message.kill) ||
         (message.kill != null &&
           ((this.opts.enableTasksQueue === false &&
-            this.workerNodes[workerNodeKey].usage.tasks.executing === 0) ||
+            workerUsage.tasks.executing === 0) ||
             (this.opts.enableTasksQueue === true &&
-              this.workerNodes[workerNodeKey].usage.tasks.executing === 0 &&
-              this.tasksQueueSize(workerNodeKey) === 0)))
+              workerUsage.tasks.executing === 0 &&
+              this.tasksQueueSize(localWorkerNodeKey) === 0)))
       ) {
         // Kill message received from the worker: no new tasks are submitted to that worker for a while ( > maxInactiveTime)
-        void (this.destroyWorker(worker) as Promise<void>)
+        const destroyWorkerNodeBounded = this.destroyWorkerNode.bind(this)
+        if (isAsyncFunction(destroyWorkerNodeBounded)) {
+          (
+            destroyWorkerNodeBounded as (workerNodeKey: number) => Promise<void>
+          )(localWorkerNodeKey).catch(EMPTY_FUNCTION)
+        } else {
+          (destroyWorkerNodeBounded as (workerNodeKey: number) => void)(
+            localWorkerNodeKey
+          )
+        }
       }
     })
-    const workerInfo = this.getWorkerInfoByWorker(worker)
+    const workerInfo = this.getWorkerInfo(workerNodeKey)
     workerInfo.dynamic = true
     if (this.workerChoiceStrategyContext.getStrategyPolicy().useDynamicWorker) {
       workerInfo.ready = true
     }
-    this.sendToWorker(worker, {
+    this.sendToWorker(workerNodeKey, {
       checkActive: true,
       workerId: workerInfo.id as number
     })
-    return worker
+    return workerNodeKey
   }
 
   /**
-   * Registers a listener callback on the given worker.
+   * Registers a listener callback on the worker given its worker node key.
    *
-   * @param worker - The worker which should register a listener.
+   * @param workerNodeKey - The worker node key.
    * @param listener - The message listener callback.
    */
   protected abstract registerWorkerMessageListener<
     Message extends Data | Response
-  >(worker: Worker, listener: (message: MessageValue<Message>) => void): void
+  >(
+    workerNodeKey: number,
+    listener: (message: MessageValue<Message>) => void
+  ): void
 
   /**
-   * Function that can be hooked up when a worker has been newly created and moved to the pool worker nodes.
+   * Method hooked up after a worker node has been newly created.
    * Can be overridden.
    *
-   * @param worker - The newly created worker.
+   * @param workerNodeKey - The newly created worker node key.
    */
-  protected afterWorkerSetup (worker: Worker): void {
+  protected afterWorkerNodeSetup (workerNodeKey: number): void {
     // Listen to worker messages.
-    this.registerWorkerMessageListener(worker, this.workerListener())
+    this.registerWorkerMessageListener(workerNodeKey, this.workerListener())
     // Send the startup message to worker.
-    this.sendStartupMessageToWorker(worker)
-    // Setup worker task statistics computation.
-    this.setWorkerStatistics(worker)
+    this.sendStartupMessageToWorker(workerNodeKey)
+    // Send the worker statistics message to worker.
+    this.sendWorkerStatisticsMessageToWorker(workerNodeKey)
   }
 
   /**
-   * Sends the startup message to the given worker.
+   * Sends the startup message to worker given its worker node key.
    *
-   * @param worker - The worker which should receive the startup message.
+   * @param workerNodeKey - The worker node key.
    */
-  protected abstract sendStartupMessageToWorker (worker: Worker): void
+  protected abstract sendStartupMessageToWorker (workerNodeKey: number): void
+
+  /**
+   * Sends the worker statistics message to worker given its worker node key.
+   *
+   * @param workerNodeKey - The worker node key.
+   */
+  private sendWorkerStatisticsMessageToWorker (workerNodeKey: number): void {
+    this.sendToWorker(workerNodeKey, {
+      statistics: {
+        runTime:
+          this.workerChoiceStrategyContext.getTaskStatisticsRequirements()
+            .runTime.aggregate,
+        elu: this.workerChoiceStrategyContext.getTaskStatisticsRequirements()
+          .elu.aggregate
+      },
+      workerId: this.getWorkerInfo(workerNodeKey).id as number
+    })
+  }
 
   private redistributeQueuedTasks (workerNodeKey: number): void {
     while (this.tasksQueueSize(workerNodeKey) > 0) {
       let targetWorkerNodeKey: number = workerNodeKey
       let minQueuedTasks = Infinity
+      let executeTask = false
       for (const [workerNodeId, workerNode] of this.workerNodes.entries()) {
         const workerInfo = this.getWorkerInfo(workerNodeId)
         if (
@@ -960,6 +1012,12 @@ export abstract class AbstractPool<
           workerInfo.ready &&
           workerNode.usage.tasks.queued === 0
         ) {
+          if (
+            this.workerNodes[workerNodeId].usage.tasks.executing <
+            (this.opts.tasksQueueOptions?.concurrency as number)
+          ) {
+            executeTask = true
+          }
           targetWorkerNodeKey = workerNodeId
           break
         }
@@ -972,15 +1030,22 @@ export abstract class AbstractPool<
           targetWorkerNodeKey = workerNodeId
         }
       }
-      this.enqueueTask(
-        targetWorkerNodeKey,
-        this.dequeueTask(workerNodeKey) as Task<Data>
-      )
+      if (executeTask) {
+        this.executeTask(
+          targetWorkerNodeKey,
+          this.dequeueTask(workerNodeKey) as Task<Data>
+        )
+      } else {
+        this.enqueueTask(
+          targetWorkerNodeKey,
+          this.dequeueTask(workerNodeKey) as Task<Data>
+        )
+      }
     }
   }
 
   /**
-   * This function is the listener registered for each worker message.
+   * This method is the listener registered for each worker message.
    *
    * @returns The listener function to execute when a message is received from a worker.
    */
@@ -998,8 +1063,8 @@ export abstract class AbstractPool<
   }
 
   private handleWorkerReadyResponse (message: MessageValue<Response>): void {
-    this.getWorkerInfoByWorker(
-      this.getWorkerById(message.workerId) as Worker
+    this.getWorkerInfo(
+      this.getWorkerNodeKeyByWorkerId(message.workerId) as number
     ).ready = message.ready as boolean
     if (this.emitter != null && this.ready) {
       this.emitter.emit(PoolEvents.ready, this.info)
@@ -1043,27 +1108,12 @@ export abstract class AbstractPool<
   }
 
   /**
-   * Gets the worker information from the given worker node key.
+   * Gets the worker information given its worker node key.
    *
    * @param workerNodeKey - The worker node key.
    * @returns The worker information.
    */
-  private getWorkerInfo (workerNodeKey: number): WorkerInfo {
-    return this.workerNodes[workerNodeKey].info
-  }
-
-  /**
-   * Gets the worker information from the given worker.
-   *
-   * @param worker - The worker.
-   * @returns The worker information.
-   * @throws {@link https://nodejs.org/api/errors.html#class-error} If the worker is not found.
-   */
-  protected getWorkerInfoByWorker (worker: Worker): WorkerInfo {
-    const workerNodeKey = this.getWorkerNodeKey(worker)
-    if (workerNodeKey === -1) {
-      throw new Error('Worker not found')
-    }
+  protected getWorkerInfo (workerNodeKey: number): WorkerInfo {
     return this.workerNodes[workerNodeKey].info
   }
 
@@ -1071,7 +1121,8 @@ export abstract class AbstractPool<
    * Adds the given worker in the pool worker nodes.
    *
    * @param worker - The worker.
-   * @returns The worker nodes length.
+   * @returns The added worker node key.
+   * @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)
@@ -1079,7 +1130,12 @@ export abstract class AbstractPool<
     if (this.starting) {
       workerNode.info.ready = true
     }
-    return this.workerNodes.push(workerNode)
+    this.workerNodes.push(workerNode)
+    const workerNodeKey = this.getWorkerNodeKey(worker)
+    if (workerNodeKey === -1) {
+      throw new Error('Worker node not found')
+    }
+    return workerNodeKey
   }
 
   /**
@@ -1096,14 +1152,14 @@ export abstract class AbstractPool<
   }
 
   /**
-   * Executes the given task on the given worker.
+   * Executes the given task on the worker given its worker node key.
    *
-   * @param worker - The worker.
+   * @param workerNodeKey - The worker node key.
    * @param task - The task to execute.
    */
   private executeTask (workerNodeKey: number, task: Task<Data>): void {
     this.beforeTaskExecutionHook(workerNodeKey, task)
-    this.sendToWorker(this.workerNodes[workerNodeKey].worker, task)
+    this.sendToWorker(workerNodeKey, task)
   }
 
   private enqueueTask (workerNodeKey: number, task: Task<Data>): number {
@@ -1133,17 +1189,4 @@ export abstract class AbstractPool<
       this.flushTasksQueue(workerNodeKey)
     }
   }
-
-  private setWorkerStatistics (worker: Worker): void {
-    this.sendToWorker(worker, {
-      statistics: {
-        runTime:
-          this.workerChoiceStrategyContext.getTaskStatisticsRequirements()
-            .runTime.aggregate,
-        elu: this.workerChoiceStrategyContext.getTaskStatisticsRequirements()
-          .elu.aggregate
-      },
-      workerId: this.getWorkerInfoByWorker(worker).id as number
-    })
-  }
 }