+ * Registers a listener callback on the worker given its worker node key.
+ *
+ * @param workerNodeKey - The worker node key.
+ * @param listener - The message listener callback.
+ */
+ protected abstract registerWorkerMessageListener<
+ Message extends Data | Response
+ >(
+ workerNodeKey: number,
+ listener: (message: MessageValue<Message>) => void
+ ): void
+
+ /**
+ * Method hooked up after a worker node has been newly created.
+ * Can be overridden.
+ *
+ * @param workerNodeKey - The newly created worker node key.
+ */
+ protected afterWorkerNodeSetup (workerNodeKey: number): void {
+ // Listen to worker messages.
+ this.registerWorkerMessageListener(workerNodeKey, this.workerListener())
+ // Send the startup message to worker.
+ this.sendStartupMessageToWorker(workerNodeKey)
+ // Send the worker statistics message to worker.
+ this.sendWorkerStatisticsMessageToWorker(workerNodeKey)
+ }
+
+ /**
+ * Sends the startup message to worker given its worker node key.
+ *
+ * @param workerNodeKey - The worker node key.
+ */
+ 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 (
+ workerNodeId !== workerNodeKey &&
+ 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
+ }
+ if (
+ workerNodeId !== workerNodeKey &&
+ workerInfo.ready &&
+ workerNode.usage.tasks.queued < minQueuedTasks
+ ) {
+ minQueuedTasks = workerNode.usage.tasks.queued
+ targetWorkerNodeKey = workerNodeId
+ }
+ }
+ if (executeTask) {
+ this.executeTask(
+ targetWorkerNodeKey,
+ this.dequeueTask(workerNodeKey) as Task<Data>
+ )
+ } else {
+ this.enqueueTask(
+ targetWorkerNodeKey,
+ this.dequeueTask(workerNodeKey) as Task<Data>
+ )
+ }
+ }
+ }
+
+ /**
+ * This method is the listener registered for each worker message.