WorkerSet: remove ugly hack to deal with async worker message handler

[e-mobility-charging-stations-simulator.git] / src / worker / WorkerSet.ts

diff --git a/src/worker/WorkerSet.ts b/src/worker/WorkerSet.ts
index 81a6b05fdc3f1898c73cb99b18ed4a7f1bbf85a3..f41752fc7a2b088fda4b8c68b4b74bec347b1bf9 100644 (file)
--- a/src/worker/WorkerSet.ts
+++ b/src/worker/WorkerSet.ts
@@ -1,15 +1,15 @@
 // Partial Copyright Jerome Benoit. 2021. All Rights Reserved.
 
-import { WorkerData, WorkerMessageEvents, WorkerOptions, WorkerSetElement } from '../types/Worker';
+import { Worker } from 'worker_threads';
 
+import { WorkerData, WorkerMessageEvents, WorkerOptions, WorkerSetElement } from '../types/Worker';
 import Utils from '../utils/Utils';
-import { Worker } from 'worker_threads';
 import WorkerAbstract from './WorkerAbstract';
 import { WorkerUtils } from './WorkerUtils';
 
 export default class WorkerSet extends WorkerAbstract<WorkerData> {
   private readonly workerSet: Set<WorkerSetElement>;
-  private readonly messageHandler: (message: unknown) => void | Promise<void>;
+  private readonly messageHandler: (message: unknown) => void;
 
   /**
    * Create a new `WorkerSet`.
@@ -20,7 +20,11 @@ export default class WorkerSet extends WorkerAbstract<WorkerData> {
   constructor(workerScript: string, workerOptions?: WorkerOptions) {
     super(workerScript, workerOptions);
     this.workerSet = new Set<WorkerSetElement>();
-    this.messageHandler = workerOptions?.messageHandler ?? (() => { /* This is intentional */ });
+    this.messageHandler =
+      workerOptions?.messageHandler ??
+      (() => {
+        /* This is intentional */
+      });
   }
 
   get size(): number {
@@ -39,14 +43,23 @@ export default class WorkerSet extends WorkerAbstract<WorkerData> {
    */
   public async addElement(elementData: WorkerData): Promise<void> {
     if (!this.workerSet) {
-      throw new Error('Cannot add a WorkerSet element: workers\' set does not exist');
+      throw new Error("Cannot add a WorkerSet element: workers' set does not exist");
     }
-    if (this.getLastWorkerSetElement().numberOfWorkerElements >= this.workerOptions.elementsPerWorker) {
+    if (
+      this.workerSet.size === 0 ||
+      this.getLastWorkerSetElement().numberOfWorkerElements >= this.workerOptions.elementsPerWorker
+    ) {
       await this.startWorker();
     }
-    this.getLastWorker().postMessage({ id: WorkerMessageEvents.START_WORKER_ELEMENT, data: elementData });
+    this.getLastWorker().postMessage({
+      id: WorkerMessageEvents.START_WORKER_ELEMENT,
+      data: elementData,
+    });
     this.getLastWorkerSetElement().numberOfWorkerElements++;
-    this.workerOptions.elementStartDelay > 0 && await Utils.sleep(this.workerOptions.elementStartDelay);
+    // Start element sequentially to optimize memory at startup
+    if (this.workerOptions.elementStartDelay > 0) {
+      await Utils.sleep(this.workerOptions.elementStartDelay);
+    }
   }
 
   /**
@@ -76,24 +89,23 @@ export default class WorkerSet extends WorkerAbstract<WorkerData> {
    */
   private async startWorker(): Promise<void> {
     const worker = new Worker(this.workerScript);
-    worker.on('message', (msg) => {
-      (async () => {
-        await this.messageHandler(msg);
-      })().catch(() => { /* This is intentional */ });
-    });
-    worker.on('error', () => { /* This is intentional */ });
+    worker.on('message', this.messageHandler);
+    worker.on('error', WorkerUtils.defaultErrorHandler);
     worker.on('exit', (code) => {
       WorkerUtils.defaultExitHandler(code);
       this.workerSet.delete(this.getWorkerSetElementByWorker(worker));
     });
     this.workerSet.add({ worker, numberOfWorkerElements: 0 });
     // Start worker sequentially to optimize memory at startup
-    this.workerOptions.workerStartDelay > 0 && await Utils.sleep(this.workerOptions.workerStartDelay);
+    this.workerOptions.workerStartDelay > 0 &&
+      (await Utils.sleep(this.workerOptions.workerStartDelay));
   }
 
   private getLastWorkerSetElement(): WorkerSetElement {
     let workerSetElement: WorkerSetElement;
-    for (workerSetElement of this.workerSet) { /* This is intentional */ }
+    for (workerSetElement of this.workerSet) {
+      /* This is intentional */
+    }
     return workerSetElement;
   }