Fix #42839. avoid ui freeze when file is larger than heap size limit.

src/main.js

@@ -162,6 +162,21 @@ function touch(file) {
 	});
 }
 
+function resolveJSFlags() {
+	let jsFlags = [];
+	if (args['js-flags']) {
+		jsFlags.push(args['js-flag']);
+	}
+	if (args['max_old_space_size'] && !/max_old_space_size=(\d+)/g.exec(args['js-flags'])) {
+		jsFlags.push(`--max_old_space_size=${args['max_old_space_size']}`);
+	}
+	if (jsFlags.length > 0) {
+		return jsFlags.join(' ');
+	} else {
+		return null;
+	}
+}
+
 // Language tags are case insensitve however an amd loader is case sensitive
 // To make this work on case preserving & insensitive FS we do the following:
 // the language bundles have lower case language tags and we always lower case
@@ -441,7 +456,8 @@ let nodeCachedDataDir = getNodeCachedDataDir().then(function (value) {
 
 		// tell v8 to not be lazy when parsing JavaScript. Generally this makes startup slower
 		// but because we generate cached data it makes subsequent startups much faster
-		app.commandLine.appendSwitch('--js-flags', '--nolazy');
+		let existingJSFlags = resolveJSFlags();
+		app.commandLine.appendSwitch('--js-flags', existingJSFlags ? existingJSFlags + ' --nolazy' : '--nolazy');
 	}
 	return value;
 });
@@ -454,6 +470,11 @@ userDefinedLocale.then((locale) => {
 	}
 });
 
+let jsFlags = resolveJSFlags();
+if (jsFlags) {
+	app.commandLine.appendSwitch('--js-flags', jsFlags);
+}
+
 // Load our code once ready
 app.once('ready', function () {
 	perf.mark('main:appReady');

src/vs/code/node/cli.ts

@@ -306,6 +306,13 @@ export async function main(argv: string[]): TPromise<any> {
 			});
 		}
 
+		if (args['js-flags']) {
+			const match = /max_old_space_size=(\d+)/g.exec(args['js-flags']);
+			if (match && !args['max_old_space_size']) {
+				argv.push(`--max_old_space_size=${match[1]}`);
+			}
+		}
+
 		const options = {
 			detached: true,
 			env

src/vs/platform/environment/common/environment.ts

@@ -53,6 +53,7 @@ export interface ParsedArgs {
 	'disable-updates'?: string;
 	'disable-crash-reporter'?: string;
 	'skip-add-to-recently-opened'?: boolean;
+	'max_old_space_size'?: number;
 	'file-write'?: boolean;
 	'file-chmod'?: boolean;
 	'upload-logs'?: string;

src/vs/platform/environment/node/argv.ts

@@ -167,6 +167,7 @@ const troubleshootingHelp: { [name: string]: string; } = {
 	'--inspect-brk-extensions': localize('inspect-brk-extensions', "Allow debugging and profiling of extensions with the extension host being paused after start. Check the developer tools for the connection uri."),
 	'--disable-gpu': localize('disableGPU', "Disable GPU hardware acceleration."),
 	'--upload-logs': localize('uploadLogs', "Uploads logs from current session to a secure endpoint."),
+	'--max_old_space_size': localize('maxOldSpaceSize', "Max size of the old space (in Mbytes).")
 };
 
 export function formatOptions(options: { [name: string]: string; }, columns: number): string {

src/vs/platform/files/common/files.ts

@@ -604,7 +604,8 @@ export enum FileOperationResult {
 	FILE_READ_ONLY,
 	FILE_PERMISSION_DENIED,
 	FILE_TOO_LARGE,
-	FILE_INVALID_PATH
+	FILE_INVALID_PATH,
+	FILE_EXCEED_HEAP
 }
 
 export const AutoSaveConfiguration = {

src/vs/platform/files/node/files.ts

@@ -7,4 +7,9 @@
 const WIN32_MAX_FILE_SIZE = 300 * 1024 * 1024; // 300 MB
 const GENERAL_MAX_FILE_SIZE = 16 * 1024 * 1024 * 1024; // 16 GB
 
-export const MAX_FILE_SIZE = process.arch === 'ia32' ? WIN32_MAX_FILE_SIZE : GENERAL_MAX_FILE_SIZE;
+// See https://github.com/v8/v8/blob/5918a23a3d571b9625e5cce246bdd5b46ff7cd8b/src/heap/heap.cc#L149
+const WIN32_MAX_HEAP_SIZE = 700 * 1024 * 1024; // 700 MB
+const GENERAL_MAX_HEAP_SIZE = 700 * 2 * 1024 * 1024; // 1400 MB
+
+export const MAX_FILE_SIZE = process.arch === 'ia32' ? WIN32_MAX_FILE_SIZE : GENERAL_MAX_FILE_SIZE;
+export const MAX_HEAP_SIZE = process.arch === 'ia32' ? WIN32_MAX_HEAP_SIZE : GENERAL_MAX_HEAP_SIZE;

src/vs/workbench/services/files/electron-browser/fileService.ts

@@ -84,7 +84,7 @@ export class FileService implements IFileService {
 		};
 
 		// create service
-		this.raw = new NodeFileService(contextService, textResourceConfigurationService, configurationService, lifecycleService, fileServiceConfig);
+		this.raw = new NodeFileService(contextService, environmentService, textResourceConfigurationService, configurationService, lifecycleService, fileServiceConfig);
 
 		// Listeners
 		this.registerListeners();

src/vs/workbench/services/files/node/fileService.ts

@@ -11,7 +11,7 @@ import os = require('os');
 import crypto = require('crypto');
 import assert = require('assert');
 import { isParent, FileOperation, FileOperationEvent, IContent, IFileService, IResolveFileOptions, IResolveFileResult, IResolveContentOptions, IFileStat, IStreamContent, FileOperationError, FileOperationResult, IUpdateContentOptions, FileChangeType, IImportResult, FileChangesEvent, ICreateFileOptions, IContentData, ITextSnapshot } from 'vs/platform/files/common/files';
-import { MAX_FILE_SIZE } from 'vs/platform/files/node/files';
+import { MAX_FILE_SIZE, MAX_HEAP_SIZE } from 'vs/platform/files/node/files';
 import { isEqualOrParent } from 'vs/base/common/paths';
 import { ResourceMap } from 'vs/base/common/map';
 import arrays = require('vs/base/common/arrays');
@@ -36,6 +36,7 @@ import Event, { Emitter } from 'vs/base/common/event';
 import { FileWatcher as NsfwWatcherService } from 'vs/workbench/services/files/node/watcher/nsfw/watcherService';
 import { ITextResourceConfigurationService } from 'vs/editor/common/services/resourceConfiguration';
 import { IConfigurationService } from 'vs/platform/configuration/common/configuration';
+import { IEnvironmentService } from 'vs/platform/environment/common/environment';
 import { CancellationToken, CancellationTokenSource } from 'vs/base/common/cancellation';
 import { ILifecycleService, LifecyclePhase } from 'vs/platform/lifecycle/common/lifecycle';
 import { getBaseLabel } from 'vs/base/common/labels';
@@ -131,6 +132,7 @@ export class FileService implements IFileService {
 
 	constructor(
 		private contextService: IWorkspaceContextService,
+		private environmentService: IEnvironmentService,
 		private textResourceConfigurationService: ITextResourceConfigurationService,
 		private configurationService: IConfigurationService,
 		private lifecycleService: ILifecycleService,
@@ -316,12 +318,20 @@ export class FileService implements IFileService {
 			}
 
 			// Return early if file is too large to load
-			if (typeof stat.size === 'number' && stat.size > MAX_FILE_SIZE) {
-				return onStatError(new FileOperationError(
-					nls.localize('fileTooLargeError', "File too large to open"),
-					FileOperationResult.FILE_TOO_LARGE,
-					options
-				));
+			if (typeof stat.size === 'number') {
+				if (stat.size > Math.max(this.environmentService.args['max_old_space_size'] * 1024 * 1024 || 0, MAX_HEAP_SIZE)) {
+					return onStatError(new FileOperationError(
+						nls.localize('fileTooLargeForHeapError', "File size exceeds V8 heap limit, please try to run code --max_old_space_size=NEWSIZE"),
+						FileOperationResult.FILE_EXCEED_HEAP
+					));
+				}
+
+				if (stat.size > MAX_FILE_SIZE) {
+					return onStatError(new FileOperationError(
+						nls.localize('fileTooLargeError', "File too large to open"),
+						FileOperationResult.FILE_TOO_LARGE
+					));
+				}
 			}
 
 			return void 0;
@@ -455,6 +465,13 @@ export class FileService implements IFileService {
 							currentPosition += bytesRead;
 						}
 
+						if (totalBytesRead > Math.max(this.environmentService.args['max_old_space_size'] * 1024 * 1024 || 0, MAX_HEAP_SIZE)) {
+							finish(new FileOperationError(
+								nls.localize('fileTooLargeForHeapError', "File size exceeds V8 heap limit, please try to run code --max_old_space_size=NEWSIZE"),
+								FileOperationResult.FILE_EXCEED_HEAP
+							));
+						}
+
 						if (totalBytesRead > MAX_FILE_SIZE) {
 							// stop when reading too much
 							finish(new FileOperationError(