Add an option to control the resources available to workers.

common/changes/@rushstack/module-minifier/add-workerResourceLimits_2025-01-22-02-09.json

@@ -0,0 +1,10 @@
+{
+  "changes": [
+    {
+      "packageName": "@rushstack/module-minifier",
+      "comment": "Add a `workerResourceLimits` option to the `WorkerPoolMinifier` constructor to control the available resources to the workers.",
+      "type": "minor"
+    }
+  ],
+  "packageName": "@rushstack/module-minifier"
+}

common/changes/@rushstack/worker-pool/add-workerResourceLimits_2025-01-22-02-09.json

@@ -0,0 +1,10 @@
+{
+  "changes": [
+    {
+      "packageName": "@rushstack/worker-pool",
+      "comment": "Add a `workerResourceLimits` option to the `WorkerPool` constructor to control the available resources to the workers.",
+      "type": "minor"
+    }
+  ],
+  "packageName": "@rushstack/worker-pool"
+}

common/reviews/api/module-minifier.api.md

@@ -8,6 +8,7 @@
 
 import { MinifyOptions } from 'terser';
 import type { RawSourceMap } from 'source-map';
+import type { ResourceLimits } from 'worker_threads';
 import type * as WorkerThreads from 'worker_threads';
 
 // @public
@@ -79,6 +80,7 @@ export interface IWorkerPoolMinifierOptions {
     maxThreads?: number;
     terserOptions?: MinifyOptions;
     verbose?: boolean;
+    workerResourceLimits?: ResourceLimits;
 }
 
 // @public

common/reviews/api/worker-pool.api.md

@@ -6,6 +6,7 @@
 
 /// <reference types="node" />
 
+import { ResourceLimits } from 'worker_threads';
 import { Worker } from 'worker_threads';
 
 // Warning: (ae-internal-missing-underscore) The name "IWorkerPoolOptions" should be prefixed with an underscore because the declaration is marked as @internal
@@ -17,6 +18,7 @@ export interface IWorkerPoolOptions {
     onWorkerDestroyed?: () => void;
     prepareWorker?: (worker: Worker) => void;
     workerData?: unknown;
+    workerResourceLimits?: ResourceLimits;
     workerScriptPath: string;
 }
 

libraries/module-minifier/src/WorkerPoolMinifier.ts

@@ -3,6 +3,7 @@
 
 import { createHash } from 'crypto';
 import { cpus } from 'os';
+import type { ResourceLimits } from 'worker_threads';
 
 import serialize from 'serialize-javascript';
 import type { MinifyOptions } from 'terser';
@@ -36,6 +37,11 @@ export interface IWorkerPoolMinifierOptions {
    * If true, log to the console about the minification results.
    */
   verbose?: boolean;
+
+  /**
+   * Optional resource limits for the workers.
+   */
+  workerResourceLimits?: ResourceLimits;
 }
 
 /**
@@ -55,15 +61,21 @@ export class WorkerPoolMinifier implements IModuleMinifier {
   private readonly _activeRequests: Map<string, IModuleMinificationCallback[]>;
 
   public constructor(options: IWorkerPoolMinifierOptions) {
-    const { maxThreads = cpus().length, terserOptions = {}, verbose = false } = options || {};
+    const {
+      maxThreads = cpus().length,
+      terserOptions = {},
+      verbose = false,
+      workerResourceLimits
+    } = options || {};
 
     const activeRequests: Map<string, IModuleMinificationCallback[]> = new Map();
     const resultCache: Map<string, IModuleMinificationResult> = new Map();
     const terserPool: WorkerPool = new WorkerPool({
       id: 'Minifier',
       maxWorkers: maxThreads,
       workerData: terserOptions,
-      workerScriptPath: require.resolve('./MinifierWorker')
+      workerScriptPath: require.resolve('./MinifierWorker'),
+      workerResourceLimits
     });
 
     const { version: terserVersion } = require('terser/package.json');

libraries/worker-pool/src/WorkerPool.ts

@@ -1,7 +1,7 @@
 // Copyright (c) Microsoft Corporation. All rights reserved. Licensed under the MIT license.
 // See LICENSE in the project root for license information.
 
-import { Worker } from 'worker_threads';
+import { type ResourceLimits, Worker } from 'worker_threads';
 
 /**
  * Symbol to read the ID off of a worker
@@ -38,6 +38,11 @@ export interface IWorkerPoolOptions {
    * Absolute path to the worker script.
    */
   workerScriptPath: string;
+
+  /**
+   * Optional resource limits for the workers.
+   */
+  workerResourceLimits?: ResourceLimits;
 }
 
 /**
@@ -60,9 +65,18 @@ export class WorkerPool {
   private readonly _prepare: ((worker: Worker) => void) | undefined;
   private readonly _workerData: unknown;
   private readonly _workerScript: string;
+  private readonly _workerResourceLimits: ResourceLimits | undefined;
 
   public constructor(options: IWorkerPoolOptions) {
-    const { id, maxWorkers, onWorkerDestroyed, prepareWorker, workerData, workerScriptPath } = options;
+    const {
+      id,
+      maxWorkers,
+      onWorkerDestroyed,
+      prepareWorker,
+      workerData,
+      workerScriptPath,
+      workerResourceLimits
+    } = options;
 
     this.id = id;
     this.maxWorkers = maxWorkers;
@@ -77,6 +91,7 @@ export class WorkerPool {
     this._prepare = prepareWorker;
     this._workerData = workerData;
     this._workerScript = workerScriptPath;
+    this._workerResourceLimits = workerResourceLimits;
   }
 
   /**
@@ -193,7 +208,8 @@ export class WorkerPool {
       [WORKER_ID_SYMBOL]?: string;
     } = new Worker(this._workerScript, {
       eval: false,
-      workerData: this._workerData
+      workerData: this._workerData,
+      resourceLimits: this._workerResourceLimits
     });
 
     const id: string = `${this.id}#${++this._nextId}`;