From 0a3b4bd9134f434a1cc262dc8a60c383d14a0b18 Mon Sep 17 00:00:00 2001
From: Rob Lourens <roblourens@gmail.com>
Date: Wed, 30 Jun 2021 16:28:04 -0700
Subject: [PATCH] Don't block on fetchCallStack requests

---
 .../breakpoints/notebookBreakpoints.ts        | 58 +++++++++++--------
 1 file changed, 34 insertions(+), 24 deletions(-)

diff --git a/src/vs/workbench/contrib/notebook/browser/contrib/breakpoints/notebookBreakpoints.ts b/src/vs/workbench/contrib/notebook/browser/contrib/breakpoints/notebookBreakpoints.ts
index 76de82bc30e1d..812c044a04d61 100644
--- a/src/vs/workbench/contrib/notebook/browser/contrib/breakpoints/notebookBreakpoints.ts
+++ b/src/vs/workbench/contrib/notebook/browser/contrib/breakpoints/notebookBreakpoints.ts
@@ -10,7 +10,7 @@ import { isEqual } from 'vs/base/common/resources';
 import { URI } from 'vs/base/common/uri';
 import { Registry } from 'vs/platform/registry/common/platform';
 import { Extensions as WorkbenchExtensions, IWorkbenchContribution, IWorkbenchContributionsRegistry } from 'vs/workbench/common/contributions';
-import { IDebugService } from 'vs/workbench/contrib/debug/common/debug';
+import { IDebugService, IThread } from 'vs/workbench/contrib/debug/common/debug';
 import { Thread } from 'vs/workbench/contrib/debug/common/debugModel';
 import { NotebookTextModel } from 'vs/workbench/contrib/notebook/common/model/notebookTextModel';
 import { CellEditType, CellUri, NotebookCellsChangeType } from 'vs/workbench/contrib/notebook/common/notebookCommon';
@@ -104,39 +104,49 @@ class NotebookCellPausing extends Disposable implements IWorkbenchContribution {
 	private readonly _pausedCells = new Set<string>();
 
 	constructor(
-		@IDebugService _debugService: IDebugService,
+		@IDebugService private readonly _debugService: IDebugService,
 		@INotebookService private readonly _notebookService: INotebookService
 	) {
 		super();
 
-		this._register(_debugService.getModel().onDidChangeCallStack(async () => {
-			const newPausedCells = new Set<string>();
-			for (const session of _debugService.getModel().getSessions()) {
-				for (const thread of session.getAllThreads()) {
-					const callStack = thread.getCallStack();
-					if (!callStack.length) {
-						await (thread as Thread).fetchCallStack();
-					}
+		this._register(_debugService.getModel().onDidChangeCallStack(this.onDidChangeCallStack, this));
+	}
 
-					thread.getCallStack().forEach(sf => {
-						const parsed = CellUri.parse(sf.source.uri);
-						if (parsed) {
-							newPausedCells.add(sf.source.uri.toString());
-							this.editIsPaused(sf.source.uri, true);
-						}
-					});
+	private async onDidChangeCallStack(): Promise<void> {
+		const newPausedCells = new Set<string>();
+
+		const updateForThread = (thread: IThread): void => {
+			thread.getCallStack().forEach(sf => {
+				const parsed = CellUri.parse(sf.source.uri);
+				if (parsed) {
+					newPausedCells.add(sf.source.uri.toString());
+					this.editIsPaused(sf.source.uri, true);
+				}
+			});
+		};
+
+		const promises: Promise<void>[] = [];
+		for (const session of this._debugService.getModel().getSessions()) {
+			for (const thread of session.getAllThreads()) {
+				const callStack = thread.getCallStack();
+				if (callStack.length) {
+					updateForThread(thread);
+				} else {
+					promises.push(
+						(thread as Thread).fetchCallStack().then(() => updateForThread(thread)));
 				}
 			}
+		}
 
-			for (const uri of this._pausedCells) {
-				if (!newPausedCells.has(uri)) {
-					this.editIsPaused(URI.parse(uri), false);
-					this._pausedCells.delete(uri);
-				}
+		await Promise.all(promises);
+		for (const uri of this._pausedCells) {
+			if (!newPausedCells.has(uri)) {
+				this.editIsPaused(URI.parse(uri), false);
+				this._pausedCells.delete(uri);
 			}
+		}
 
-			newPausedCells.forEach(cell => this._pausedCells.add(cell));
-		}));
+		newPausedCells.forEach(cell => this._pausedCells.add(cell));
 	}
 
 	private editIsPaused(cellUri: URI, isPaused: boolean) {