WRR: Fix worker choice initial runtime value on each round

[poolifier.git] / src / pools / selection-strategies / weighted-round-robin-worker-choice-strategy.ts

diff --git a/src/pools/selection-strategies/weighted-round-robin-worker-choice-strategy.ts b/src/pools/selection-strategies/weighted-round-robin-worker-choice-strategy.ts
index 6e48f82f2bc877bcf396e0631fb02d9f76dab9a0..4b1e5382af333d2edb59eb5ae41d1c5132f6ccb3 100644 (file)
--- a/src/pools/selection-strategies/weighted-round-robin-worker-choice-strategy.ts
+++ b/src/pools/selection-strategies/weighted-round-robin-worker-choice-strategy.ts
@@ -1,11 +1,11 @@
 import { cpus } from 'os'
-import type { AbstractPoolWorker } from '../abstract-pool-worker'
 import type { IPoolInternal } from '../pool-internal'
+import type { IPoolWorker } from '../pool-worker'
 import { AbstractWorkerChoiceStrategy } from './abstract-worker-choice-strategy'
 import type { RequiredStatistics } from './selection-strategies-types'
 
 /**
- * Task run time.
+ * Virtual task runtime.
  */
 type TaskRunTime = {
   weight: number
@@ -21,19 +21,15 @@ type TaskRunTime = {
  * @template Response Type of response of execution. This can only be serializable data.
  */
 export class WeightedRoundRobinWorkerChoiceStrategy<
-  Worker extends AbstractPoolWorker,
+  Worker extends IPoolWorker,
   Data,
   Response
 > extends AbstractWorkerChoiceStrategy<Worker, Data, Response> {
   /** @inheritDoc */
-  public requiredStatistics: RequiredStatistics = {
+  public readonly requiredStatistics: RequiredStatistics = {
     runTime: true
   }
 
-  /**
-   * Worker index where the previous task was submitted.
-   */
-  private previousWorkerIndex: number = 0
   /**
    * Worker index where the current task will be submitted.
    */
@@ -41,11 +37,11 @@ export class WeightedRoundRobinWorkerChoiceStrategy<
   /**
    * Default worker weight.
    */
-  private defaultWorkerWeight: number
+  private readonly defaultWorkerWeight: number
   /**
-   * Per worker task runtime map.
+   * Per worker virtual task runtime map.
    */
-  private workerTaskRunTime: Map<Worker, TaskRunTime> = new Map<
+  private readonly workersTaskRunTime: Map<Worker, TaskRunTime> = new Map<
     Worker,
     TaskRunTime
   >()
@@ -58,74 +54,85 @@ export class WeightedRoundRobinWorkerChoiceStrategy<
   public constructor (pool: IPoolInternal<Worker, Data, Response>) {
     super(pool)
     this.defaultWorkerWeight = this.computeWorkerWeight()
-    this.initWorkerTaskRunTime()
+    this.initWorkersTaskRunTime()
+  }
+
+  /** @inheritDoc */
+  public reset (): boolean {
+    this.currentWorkerIndex = 0
+    this.workersTaskRunTime.clear()
+    this.initWorkersTaskRunTime()
+    return true
   }
 
   /** @inheritDoc */
   public choose (): Worker {
-    const currentWorker = this.pool.workers[this.currentWorkerIndex]
-    if (this.isDynamicPool === true) {
-      this.workerTaskRunTime.has(currentWorker) === false &&
-        this.workerTaskRunTime.set(currentWorker, {
-          weight: this.defaultWorkerWeight,
-          runTime: 0
-        })
+    const chosenWorker = this.pool.workers[this.currentWorkerIndex]
+    if (
+      this.isDynamicPool === true &&
+      this.workersTaskRunTime.has(chosenWorker) === false
+    ) {
+      this.initWorkerTaskRunTime(chosenWorker)
     }
-    const workerVirtualTaskRunTime =
-      this.getWorkerVirtualTaskRunTime(currentWorker) ?? 0
+    const workerTaskRunTime =
+      this.workersTaskRunTime.get(chosenWorker)?.runTime ?? 0
     const workerTaskWeight =
-      this.workerTaskRunTime.get(currentWorker)?.weight ??
+      this.workersTaskRunTime.get(chosenWorker)?.weight ??
       this.defaultWorkerWeight
-    if (this.currentWorkerIndex === this.previousWorkerIndex) {
-      const workerTaskRunTime =
-        (this.workerTaskRunTime.get(currentWorker)?.runTime ?? 0) +
-        workerVirtualTaskRunTime
-      this.workerTaskRunTime.set(currentWorker, {
-        weight: workerTaskWeight,
-        runTime: workerTaskRunTime
-      })
+    if (workerTaskRunTime < workerTaskWeight) {
+      this.setWorkerTaskRunTime(
+        chosenWorker,
+        workerTaskWeight,
+        workerTaskRunTime +
+          (this.getWorkerVirtualTaskRunTime(chosenWorker) ?? 0)
+      )
     } else {
-      this.workerTaskRunTime.set(currentWorker, {
-        weight: workerTaskWeight,
-        runTime: 0
-      })
-    }
-    if (
-      workerVirtualTaskRunTime <
-      (this.workerTaskRunTime.get(currentWorker) ?? this.defaultWorkerWeight)
-    ) {
-      this.previousWorkerIndex = this.currentWorkerIndex
-    } else {
-      this.previousWorkerIndex = this.currentWorkerIndex
       this.currentWorkerIndex =
-        this.pool.workers.length - 1 === this.currentWorkerIndex
+        this.currentWorkerIndex === this.pool.workers.length - 1
           ? 0
           : this.currentWorkerIndex + 1
+      this.setWorkerTaskRunTime(
+        this.pool.workers[this.currentWorkerIndex],
+        workerTaskWeight,
+        0
+      )
     }
-    return this.pool.workers[this.currentWorkerIndex]
+    return chosenWorker
   }
 
-  private computeWorkerWeight () {
-    let cpusCycleTimeWeight = 0
-    for (const cpu of cpus()) {
-      // CPU estimated cycle time
-      const numberOfDigit = cpu.speed.toString().length - 1
-      const cpuCycleTime = 1 / (cpu.speed / Math.pow(10, numberOfDigit))
-      cpusCycleTimeWeight += cpuCycleTime * Math.pow(10, numberOfDigit)
+  private initWorkersTaskRunTime (): void {
+    for (const worker of this.pool.workers) {
+      this.initWorkerTaskRunTime(worker)
     }
-    return cpusCycleTimeWeight / cpus().length
   }
 
-  private initWorkerTaskRunTime () {
-    for (const worker of this.pool.workers) {
-      this.workerTaskRunTime.set(worker, {
-        weight: this.defaultWorkerWeight,
-        runTime: 0
-      })
-    }
+  private initWorkerTaskRunTime (worker: Worker): void {
+    this.setWorkerTaskRunTime(worker, this.defaultWorkerWeight, 0)
+  }
+
+  private setWorkerTaskRunTime (
+    worker: Worker,
+    weight: number,
+    runTime: number
+  ): void {
+    this.workersTaskRunTime.set(worker, {
+      weight,
+      runTime
+    })
   }
 
   private getWorkerVirtualTaskRunTime (worker: Worker): number | undefined {
     return this.pool.getWorkerAverageTasksRunTime(worker)
   }
+
+  private computeWorkerWeight (): number {
+    let cpusCycleTimeWeight = 0
+    for (const cpu of cpus()) {
+      // CPU estimated cycle time
+      const numberOfDigits = cpu.speed.toString().length - 1
+      const cpuCycleTime = 1 / (cpu.speed / Math.pow(10, numberOfDigits))
+      cpusCycleTimeWeight += cpuCycleTime * Math.pow(10, numberOfDigits)
+    }
+    return Math.round(cpusCycleTimeWeight / cpus().length)
+  }
 }