Go back to using setImmediate for background tokenization (microsoft#138887)

Author: alexdima

src/vs/base/common/platform.ts

@@ -39,6 +39,7 @@ export interface INodeProcess {
 	platform: string;
 	arch: string;
 	env: IProcessEnvironment;
+	nextTick?: (callback: (...args: any[]) => void) => void;
 	versions?: {
 		electron?: string;
 	};
@@ -189,6 +190,10 @@ export const locale = _locale;
  */
 export const translationsConfigFile = _translationsConfigFile;
 
+interface ISetImmediate {
+	(callback: (...args: unknown[]) => void): void;
+}
+
 /**
  * See https://html.spec.whatwg.org/multipage/timers-and-user-prompts.html#:~:text=than%204%2C%20then-,set%20timeout%20to%204,-.
  *
@@ -227,6 +232,20 @@ export const setTimeout0 = (() => {
 	return (callback: () => void) => setTimeout(callback);
 })();
 
+export const setImmediate: ISetImmediate = (function defineSetImmediate() {
+	if (globals.setImmediate) {
+		return globals.setImmediate.bind(globals);
+	}
+	if (typeof globals.postMessage === 'function' && !globals.importScripts) {
+		return setTimeout0;
+	}
+	if (typeof nodeProcess?.nextTick === 'function') {
+		return nodeProcess.nextTick.bind(nodeProcess);
+	}
+	const _promise = Promise.resolve();
+	return (callback: (...args: unknown[]) => void) => _promise.then(callback);
+})();
+
 export const enum OperatingSystem {
 	Windows = 1,
 	Macintosh = 2,

src/vs/editor/common/model/textModelTokens.ts

@@ -15,7 +15,7 @@ import { TextModel } from 'vs/editor/common/model/textModel';
 import { Disposable } from 'vs/base/common/lifecycle';
 import { StopWatch } from 'vs/base/common/stopwatch';
 import { MultilineTokensBuilder, countEOL } from 'vs/editor/common/model/tokensStore';
-import { runWhenIdle, IdleDeadline } from 'vs/base/common/async';
+import { setImmediate } from 'vs/base/common/platform';
 
 const enum Constants {
 	CHEAP_TOKENIZATION_LENGTH_LIMIT = 2048
@@ -262,19 +262,19 @@ export class TextModelTokenization extends Disposable {
 		}
 
 		this._isScheduled = true;
-		runWhenIdle((deadline) => {
+		setImmediate(() => {
 			this._isScheduled = false;
 
 			if (this._isDisposed) {
 				// disposed in the meantime
 				return;
 			}
 
-			this._revalidateTokensNow(deadline);
+			this._revalidateTokensNow();
 		});
 	}
 
-	private _revalidateTokensNow(deadline: IdleDeadline): void {
+	private _revalidateTokensNow(): void {
 		const textModelLastLineNumber = this._textModel.getLineCount();
 
 		const MAX_ALLOWED_TIME = 1;
@@ -293,7 +293,7 @@ export class TextModelTokenization extends Disposable {
 			if (tokenizedLineNumber >= textModelLastLineNumber) {
 				break;
 			}
-		} while (this._hasLinesToTokenize() && deadline.timeRemaining() > 0);
+		} while (this._hasLinesToTokenize());
 
 		this._beginBackgroundTokenization();
 		this._textModel.setTokens(builder.tokens, !this._hasLinesToTokenize());