Only call setJumpList() after first window is opening (fixes #21963)

src/vs/code/electron-main/windows.ts

@@ -141,6 +141,8 @@ export class WindowsManager implements IWindowsMainService {
 	private windowsState: IWindowsState;
 	private lastClosedWindowState: IWindowState;
 
+	private firstWindowLoading: boolean;
+
 	private _onRecentPathsChange = new Emitter<void>();
 	onRecentPathsChange: CommonEvent<void> = this._onRecentPathsChange.event;
 
@@ -171,8 +173,6 @@ export class WindowsManager implements IWindowsMainService {
 
 		this.initialUserEnv = initialUserEnv;
 		this.windowsState = this.storageService.getItem<IWindowsState>(WindowsManager.windowsStateStorageKey) || { openedFolders: [] };
-
-		this.updateWindowsJumpList();
 	}
 
 	private registerListeners(): void {
@@ -862,6 +862,7 @@ export class WindowsManager implements IWindowsMainService {
 			vscodeWindow.win.webContents.removeAllListeners('devtools-reload-page'); // remove built in listener so we can handle this on our own
 			vscodeWindow.win.webContents.on('devtools-reload-page', () => this.reload(vscodeWindow));
 			vscodeWindow.win.webContents.on('crashed', () => this.onWindowError(vscodeWindow, WindowError.CRASHED));
+			vscodeWindow.win.webContents.on('did-start-loading', () => this.onWindowStartLoading(vscodeWindow));
 			vscodeWindow.win.on('unresponsive', () => this.onWindowError(vscodeWindow, WindowError.UNRESPONSIVE));
 			vscodeWindow.win.on('closed', () => this.onWindowClosed(vscodeWindow));
 
@@ -1264,11 +1265,26 @@ export class WindowsManager implements IWindowsMainService {
 		return pathA === pathB;
 	}
 
+	private onWindowStartLoading(win: VSCodeWindow): void {
+		if (!this.firstWindowLoading) {
+			this.firstWindowLoading = true;
+
+			// Apply jump list when our first window is loading. We do this because
+			// setJumpList() seems to take quite a bit of time and would block window
+			// loading ( = startup performance) significantly otherwise
+			setTimeout(() => this.updateWindowsJumpList()); // unwind from onWindowStartLoading event
+		}
+	}
+
 	private updateWindowsJumpList(): void {
 		if (!platform.isWindows) {
 			return; // only on windows
 		}
 
+		if (!this.firstWindowLoading) {
+			return; // push this out until a window starts loading for perf reasons
+		}
+
 		const jumpList: Electron.JumpListCategory[] = [];
 
 		// Tasks