Try to only run one mangler at a time

Also makes sure we clean up the workerpool after each run

Author: mjbvz

build/lib/mangle/index.js

@@ -406,13 +406,18 @@ export class Mangler {
 		private readonly log: typeof console.log = () => { },
 		private readonly config: { readonly manglePrivateFields: boolean; readonly mangleExports: boolean },
 	) {
-
 		this.renameWorkerPool = workerpool.pool(path.join(__dirname, 'renameWorker.js'), {
 			maxWorkers: 1,
 			minWorkers: 'max'
 		});
 	}
 
+	dispose() {
+		this.renameWorkerPool.terminate();
+		this.allClassDataByKey.clear();
+		this.allExportedSymbols.clear();
+	}
+
 	async computeNewFileContents(strictImplicitPublicHandling?: Set<string>): Promise<Map<string, MangleOutput>> {
 
 		const service = ts.createLanguageService(new StaticLanguageServiceHost(this.projectPath));

build/lib/mangle/index.ts

@@ -17,6 +17,8 @@ const { Mangler } = require('../build/lib/mangle/index');
  */
 const mangleMap = new Map();
 
+const sequentializer = Promise.resolve();
+
 /**
  * @param {string} projectPath
  */
@@ -26,7 +28,12 @@ function getMangledFileContents(projectPath) {
 		const log = (...data) => fancyLog(ansiColors.blue('[mangler]'), ...data);
 		log(`Mangling ${projectPath}`);
 		const ts2tsMangler = new Mangler(projectPath, log, { mangleExports: true, manglePrivateFields: true });
-		entry = ts2tsMangler.computeNewFileContents();
+		const mangleTask = () => {
+			return ts2tsMangler.computeNewFileContents().finally(() => {
+				ts2tsMangler.dispose();
+			});
+		};
+		entry = sequentializer.then(mangleTask, mangleTask);
 		mangleMap.set(projectPath, entry);
 	}
 
@@ -41,10 +48,7 @@ module.exports = async function (source, sourceMap, meta) {
 		// Only enable mangling in production builds
 		return source;
 	}
-	if (true) {
-		// disable mangling for now, SEE https://github.com/microsoft/vscode/issues/204692
-		return source;
-	}
+
 	const options = this.getOptions();
 	if (options.disabled) {
 		// Dynamically disabled