diff --git a/src/vs/workbench/api/browser/mainThreadDebugService.ts b/src/vs/workbench/api/browser/mainThreadDebugService.ts
index 721187994a6ac8be8c3c7038b2bd1bb21dd74a1e..fcdfb0e41788895cf6c2f2d10f109a58cbd3e7b0 100644
--- a/src/vs/workbench/api/browser/mainThreadDebugService.ts
+++ b/src/vs/workbench/api/browser/mainThreadDebugService.ts
@@ -361,23 +361,24 @@ class ExtensionHostDebugAdapter extends AbstractDebugAdapter {
 		super();
 	}
 
-	public fireError(handle: number, err: Error) {
+	fireError(handle: number, err: Error) {
 		this._onError.fire(err);
 	}
 
-	public fireExit(handle: number, code: number, signal: string) {
+	fireExit(handle: number, code: number, signal: string) {
 		this._onExit.fire(code);
 	}
 
-	public startSession(): Promise<void> {
+	startSession(): Promise<void> {
 		return Promise.resolve(this._proxy.$startDASession(this._handle, this._ds.getSessionDto(this._session)));
 	}
 
-	public sendMessage(message: DebugProtocol.ProtocolMessage): void {
+	sendMessage(message: DebugProtocol.ProtocolMessage): void {
 		this._proxy.$sendDAMessage(this._handle, convertToDAPaths(message, true));
 	}
 
-	public stopSession(): Promise<void> {
+	async stopSession(): Promise<void> {
+		await this.cancelPendingRequests();
 		return Promise.resolve(this._proxy.$stopDASession(this._handle));
 	}
 }
diff --git a/src/vs/workbench/contrib/debug/browser/debugSession.ts b/src/vs/workbench/contrib/debug/browser/debugSession.ts
index 3a3add8c50229bdf14d2e51184f175b56536d971..42da79e250d52f5cb9585c3959825ca9b31e99f9 100644
--- a/src/vs/workbench/contrib/debug/browser/debugSession.ts
+++ b/src/vs/workbench/contrib/debug/browser/debugSession.ts
@@ -33,6 +33,7 @@ import { onUnexpectedError } from 'vs/base/common/errors';
 import { INotificationService } from 'vs/platform/notification/common/notification';
 import { IOpenerService } from 'vs/platform/opener/common/opener';
 import { variableSetEmitter } from 'vs/workbench/contrib/debug/browser/variablesView';
+import { CancellationTokenSource, CancellationToken } from 'vs/base/common/cancellation';
 
 export class DebugSession implements IDebugSession {
 
@@ -43,6 +44,7 @@ export class DebugSession implements IDebugSession {
 
 	private sources = new Map<string, Source>();
 	private threads = new Map<number, Thread>();
+	private cancellationMap = new Map<number, CancellationTokenSource[]>();
 	private rawListeners: IDisposable[] = [];
 	private fetchThreadsScheduler: RunOnceScheduler | undefined;
 	private repl: ReplModel;
@@ -235,6 +237,7 @@ export class DebugSession implements IDebugSession {
 	 */
 	terminate(restart = false): Promise<void> {
 		if (this.raw) {
+			this.cancelAllRequests();
 			if (this.raw.capabilities.supportsTerminateRequest && this._configuration.resolved.request === 'launch') {
 				return this.raw.terminate(restart).then(response => {
 					return undefined;
@@ -252,6 +255,7 @@ export class DebugSession implements IDebugSession {
 	 */
 	disconnect(restart = false): Promise<void> {
 		if (this.raw) {
+			this.cancelAllRequests();
 			return this.raw.disconnect(restart).then(response => {
 				return undefined;
 			});
@@ -264,6 +268,7 @@ export class DebugSession implements IDebugSession {
 	 */
 	restart(): Promise<void> {
 		if (this.raw) {
+			this.cancelAllRequests();
 			return this.raw.restart().then(() => undefined);
 		}
 		return Promise.reject(new Error('no debug adapter'));
@@ -380,7 +385,8 @@ export class DebugSession implements IDebugSession {
 
 	stackTrace(threadId: number, startFrame: number, levels: number): Promise<DebugProtocol.StackTraceResponse> {
 		if (this.raw) {
-			return this.raw.stackTrace({ threadId, startFrame, levels });
+			const token = this.getNewCancellationToken(threadId);
+			return this.raw.stackTrace({ threadId, startFrame, levels }, token);
 		}
 		return Promise.reject(new Error('no debug adapter'));
 	}
@@ -402,16 +408,18 @@ export class DebugSession implements IDebugSession {
 		return Promise.reject(new Error('no debug adapter'));
 	}
 
-	scopes(frameId: number): Promise<DebugProtocol.ScopesResponse> {
+	scopes(frameId: number, threadId: number): Promise<DebugProtocol.ScopesResponse> {
 		if (this.raw) {
-			return this.raw.scopes({ frameId });
+			const token = this.getNewCancellationToken(threadId);
+			return this.raw.scopes({ frameId }, token);
 		}
 		return Promise.reject(new Error('no debug adapter'));
 	}
 
-	variables(variablesReference: number, filter: 'indexed' | 'named' | undefined, start: number | undefined, count: number | undefined): Promise<DebugProtocol.VariablesResponse> {
+	variables(variablesReference: number, threadId: number | undefined, filter: 'indexed' | 'named' | undefined, start: number | undefined, count: number | undefined): Promise<DebugProtocol.VariablesResponse> {
 		if (this.raw) {
-			return this.raw.variables({ variablesReference, filter, start, count });
+			const token = threadId ? this.getNewCancellationToken(threadId) : undefined;
+			return this.raw.variables({ variablesReference, filter, start, count }, token);
 		}
 		return Promise.reject(new Error('no debug adapter'));
 	}
@@ -541,14 +549,14 @@ export class DebugSession implements IDebugSession {
 		return Promise.reject(new Error('no debug adapter'));
 	}
 
-	completions(frameId: number | undefined, text: string, position: Position, overwriteBefore: number): Promise<CompletionItem[]> {
+	completions(frameId: number | undefined, text: string, position: Position, overwriteBefore: number, token: CancellationToken): Promise<CompletionItem[]> {
 		if (this.raw) {
 			return this.raw.completions({
 				frameId,
 				text,
 				column: position.column,
-				line: position.lineNumber
-			}).then(response => {
+				line: position.lineNumber,
+			}, token).then(response => {
 
 				const result: CompletionItem[] = [];
 				if (response && response.body && response.body.targets) {
@@ -757,6 +765,16 @@ export class DebugSession implements IDebugSession {
 
 		this.rawListeners.push(this.raw.onDidContinued(event => {
 			const threadId = event.body.allThreadsContinued !== false ? undefined : event.body.threadId;
+			if (threadId) {
+				const tokens = this.cancellationMap.get(threadId);
+				this.cancellationMap.delete(threadId);
+				if (tokens) {
+					tokens.forEach(t => t.cancel());
+				}
+			} else {
+				this.cancelAllRequests();
+			}
+
 			this.model.clearThreads(this.getId(), false, threadId);
 			this._onDidChangeState.fire();
 		}));
@@ -787,7 +805,7 @@ export class DebugSession implements IDebugSession {
 				source: this.getSource(event.body.source)
 			} : undefined;
 			if (event.body.variablesReference) {
-				const container = new ExpressionContainer(this, event.body.variablesReference, generateUuid());
+				const container = new ExpressionContainer(this, undefined, event.body.variablesReference, generateUuid());
 				outpuPromises.push(container.getChildren().then(children => {
 					return Promise.all(waitFor).then(() => children.forEach(child => {
 						// Since we can not display multiple trees in a row, we are displaying these variables one after the other (ignoring their names)
@@ -896,6 +914,20 @@ export class DebugSession implements IDebugSession {
 		return source;
 	}
 
+	private getNewCancellationToken(threadId: number): CancellationToken {
+		const tokenSource = new CancellationTokenSource();
+		const tokens = this.cancellationMap.get(threadId) || [];
+		tokens.push(tokenSource);
+		this.cancellationMap.set(threadId, tokens);
+
+		return tokenSource.token;
+	}
+
+	private cancelAllRequests(): void {
+		this.cancellationMap.forEach(tokens => tokens.forEach(t => t.cancel()));
+		this.cancellationMap.clear();
+	}
+
 	private getUriKey(uri: URI): string {
 		// TODO: the following code does not make sense if uri originates from a different platform
 		return platform.isLinux ? uri.toString() : uri.toString().toLowerCase();
diff --git a/src/vs/workbench/contrib/debug/browser/rawDebugSession.ts b/src/vs/workbench/contrib/debug/browser/rawDebugSession.ts
index 28e19bf76684f4bc91ca1c764c8ac1f28078faaa..2e8ce0cf55e5f453011c882899529f3990906427 100644
--- a/src/vs/workbench/contrib/debug/browser/rawDebugSession.ts
+++ b/src/vs/workbench/contrib/debug/browser/rawDebugSession.ts
@@ -19,6 +19,7 @@ import { IProcessEnvironment } from 'vs/base/common/platform';
 import { env as processEnv } from 'vs/base/common/process';
 import { IOpenerService } from 'vs/platform/opener/common/opener';
 import { IDisposable, dispose } from 'vs/base/common/lifecycle';
+import { CancellationToken } from 'vs/base/common/cancellation';
 
 /**
  * This interface represents a single command line argument split into a "prefix" and a "path" half.
@@ -112,8 +113,6 @@ export class RawDebugSession implements IDisposable {
 			}
 		}));
 
-		this.toDispose.push(this.onDidContinued(() => this.cancelPendingRequests()));
-
 		this.debugAdapter.onEvent(event => {
 			switch (event.event) {
 				case 'initialized':
@@ -346,9 +345,9 @@ export class RawDebugSession implements IDisposable {
 		return Promise.reject(new Error('restartFrame not supported'));
 	}
 
-	completions(args: DebugProtocol.CompletionsArguments): Promise<DebugProtocol.CompletionsResponse> {
+	completions(args: DebugProtocol.CompletionsArguments, token: CancellationToken): Promise<DebugProtocol.CompletionsResponse> {
 		if (this.capabilities.supportsCompletionsRequest) {
-			return this.send<DebugProtocol.CompletionsResponse>('completions', args);
+			return this.send<DebugProtocol.CompletionsResponse>('completions', args, token);
 		}
 		return Promise.reject(new Error('completions not supported'));
 	}
@@ -389,8 +388,8 @@ export class RawDebugSession implements IDisposable {
 		return Promise.reject(new Error('configurationDone not supported'));
 	}
 
-	stackTrace(args: DebugProtocol.StackTraceArguments): Promise<DebugProtocol.StackTraceResponse> {
-		return this.send<DebugProtocol.StackTraceResponse>('stackTrace', args);
+	stackTrace(args: DebugProtocol.StackTraceArguments, token: CancellationToken): Promise<DebugProtocol.StackTraceResponse> {
+		return this.send<DebugProtocol.StackTraceResponse>('stackTrace', args, token);
 	}
 
 	exceptionInfo(args: DebugProtocol.ExceptionInfoArguments): Promise<DebugProtocol.ExceptionInfoResponse> {
@@ -400,12 +399,12 @@ export class RawDebugSession implements IDisposable {
 		return Promise.reject(new Error('exceptionInfo not supported'));
 	}
 
-	scopes(args: DebugProtocol.ScopesArguments): Promise<DebugProtocol.ScopesResponse> {
-		return this.send<DebugProtocol.ScopesResponse>('scopes', args);
+	scopes(args: DebugProtocol.ScopesArguments, token: CancellationToken): Promise<DebugProtocol.ScopesResponse> {
+		return this.send<DebugProtocol.ScopesResponse>('scopes', args, token);
 	}
 
-	variables(args: DebugProtocol.VariablesArguments): Promise<DebugProtocol.VariablesResponse> {
-		return this.send<DebugProtocol.VariablesResponse>('variables', args);
+	variables(args: DebugProtocol.VariablesArguments, token?: CancellationToken): Promise<DebugProtocol.VariablesResponse> {
+		return this.send<DebugProtocol.VariablesResponse>('variables', args, token);
 	}
 
 	source(args: DebugProtocol.SourceArguments): Promise<DebugProtocol.SourceResponse> {
@@ -482,7 +481,7 @@ export class RawDebugSession implements IDisposable {
 		if (!this.inShutdown) {
 			this.inShutdown = true;
 			if (this.debugAdapter) {
-				return this.send('disconnect', { restart }, 500).then(() => {
+				return this.send('disconnect', { restart }, undefined, 500).then(() => {
 					this.stopAdapter(error);
 				}, () => {
 					// ignore error
@@ -494,23 +493,10 @@ export class RawDebugSession implements IDisposable {
 		return Promise.resolve(undefined);
 	}
 
-	private cancelPendingRequests(): void {
-		if (this.debugAdapter) {
-			if (this.capabilities.supportsCancelRequest) {
-				this.debugAdapter.getPendingRequestIds().forEach(requestId => {
-					this.cancel({ requestId });
-				});
-			} else {
-				this.debugAdapter.cancelPendingRequests();
-			}
-		}
-	}
-
 	private stopAdapter(error?: Error): Promise<any> {
 		if (this.debugAdapter) {
 			const da = this.debugAdapter;
 			this.debugAdapter = null;
-			this.cancelPendingRequests();
 			return da.stopSession().then(_ => {
 				this.debugAdapterStopped = true;
 				this.fireAdapterExitEvent(error);
@@ -642,20 +628,34 @@ export class RawDebugSession implements IDisposable {
 		return this.windowsService.openExtensionDevelopmentHostWindow(args, env);
 	}
 
-	private send<R extends DebugProtocol.Response>(command: string, args: any, timeout?: number): Promise<R> {
+	private send<R extends DebugProtocol.Response>(command: string, args: any, token?: CancellationToken, timeout?: number): Promise<R> {
 		return new Promise<R>((completeDispatch, errorDispatch) => {
 			if (!this.debugAdapter) {
 				errorDispatch(new Error('no debug adapter found'));
 				return;
 			}
-			this.debugAdapter.sendRequest(command, args, (response: R) => {
+			let cancelationListener: IDisposable;
+			const requestId = this.debugAdapter.sendRequest(command, args, (response: R) => {
+				if (cancelationListener) {
+					cancelationListener.dispose();
+				}
+
 				if (response.success) {
 					completeDispatch(response);
 				} else {
 					errorDispatch(response);
 				}
 			}, timeout);
-		}).then(response => response, err => Promise.reject(this.handleErrorResponse(err)));
+
+			if (token) {
+				cancelationListener = token.onCancellationRequested(() => {
+					cancelationListener.dispose();
+					if (this.capabilities.supportsCancelRequest) {
+						this.cancel({ requestId });
+					}
+				});
+			}
+		}).then(undefined, err => Promise.reject(this.handleErrorResponse(err)));
 	}
 
 	private handleErrorResponse(errorResponse: DebugProtocol.Response): Error {
diff --git a/src/vs/workbench/contrib/debug/browser/repl.ts b/src/vs/workbench/contrib/debug/browser/repl.ts
index 3b32a852e44f0ead40ea28983164eefaec3010d8..ba438198881b1484b5838b03fcf135b5912ba87e 100644
--- a/src/vs/workbench/contrib/debug/browser/repl.ts
+++ b/src/vs/workbench/contrib/debug/browser/repl.ts
@@ -149,7 +149,7 @@ export class Repl extends Panel implements IPrivateReplService, IHistoryNavigati
 								const text = model.getLineContent(position.lineNumber);
 								const focusedStackFrame = this.debugService.getViewModel().focusedStackFrame;
 								const frameId = focusedStackFrame ? focusedStackFrame.frameId : undefined;
-								const suggestions = await session.completions(frameId, text, position, overwriteBefore);
+								const suggestions = await session.completions(frameId, text, position, overwriteBefore, token);
 								return { suggestions };
 							}
 
diff --git a/src/vs/workbench/contrib/debug/common/abstractDebugAdapter.ts b/src/vs/workbench/contrib/debug/common/abstractDebugAdapter.ts
index f288628f314314644dcf749015f204e90e7c67b2..56a9de64e264d1a7fd06058cfbb59e4b695f2ab3 100644
--- a/src/vs/workbench/contrib/debug/common/abstractDebugAdapter.ts
+++ b/src/vs/workbench/contrib/debug/common/abstractDebugAdapter.ts
@@ -71,7 +71,7 @@ export abstract class AbstractDebugAdapter implements IDebugAdapter {
 		}
 	}
 
-	sendRequest(command: string, args: any, clb: (result: DebugProtocol.Response) => void, timeout?: number): void {
+	sendRequest(command: string, args: any, clb: (result: DebugProtocol.Response) => void, timeout?: number): number {
 		const request: any = {
 			command: command
 		};
@@ -101,6 +101,8 @@ export abstract class AbstractDebugAdapter implements IDebugAdapter {
 			// store callback for this request
 			this.pendingRequests.set(request.seq, clb);
 		}
+
+		return request.seq;
 	}
 
 	acceptMessage(message: DebugProtocol.ProtocolMessage): void {
@@ -137,7 +139,11 @@ export abstract class AbstractDebugAdapter implements IDebugAdapter {
 		this.sendMessage(message);
 	}
 
-	async cancelPendingRequests(): Promise<void> {
+	protected async cancelPendingRequests(): Promise<void> {
+		if (this.pendingRequests.size === 0) {
+			return Promise.resolve();
+		}
+
 		const pending = new Map<number, (e: DebugProtocol.Response) => void>();
 		this.pendingRequests.forEach((value, key) => pending.set(key, value));
 		await timeout(500);
diff --git a/src/vs/workbench/contrib/debug/common/debug.ts b/src/vs/workbench/contrib/debug/common/debug.ts
index 7900963c47c962c529a68d2f52084eba79ae519b..8f09afa61651745d8dd445696f606b81653aee43 100644
--- a/src/vs/workbench/contrib/debug/common/debug.ts
+++ b/src/vs/workbench/contrib/debug/common/debug.ts
@@ -210,8 +210,8 @@ export interface IDebugSession extends ITreeElement {
 
 	stackTrace(threadId: number, startFrame: number, levels: number): Promise<DebugProtocol.StackTraceResponse>;
 	exceptionInfo(threadId: number): Promise<IExceptionInfo | undefined>;
-	scopes(frameId: number): Promise<DebugProtocol.ScopesResponse>;
-	variables(variablesReference: number, filter: 'indexed' | 'named' | undefined, start: number | undefined, count: number | undefined): Promise<DebugProtocol.VariablesResponse>;
+	scopes(frameId: number, threadId: number): Promise<DebugProtocol.ScopesResponse>;
+	variables(variablesReference: number, threadId: number | undefined, filter: 'indexed' | 'named' | undefined, start: number | undefined, count: number | undefined): Promise<DebugProtocol.VariablesResponse>;
 	evaluate(expression: string, frameId?: number, context?: string): Promise<DebugProtocol.EvaluateResponse>;
 	customRequest(request: string, args: any): Promise<DebugProtocol.Response>;
 
@@ -225,7 +225,7 @@ export interface IDebugSession extends ITreeElement {
 	pause(threadId: number): Promise<void>;
 	terminateThreads(threadIds: number[]): Promise<void>;
 
-	completions(frameId: number | undefined, text: string, position: Position, overwriteBefore: number): Promise<CompletionItem[]>;
+	completions(frameId: number | undefined, text: string, position: Position, overwriteBefore: number, token: CancellationToken): Promise<CompletionItem[]>;
 	setVariable(variablesReference: number | undefined, name: string, value: string): Promise<DebugProtocol.SetVariableResponse>;
 	loadSource(resource: uri): Promise<DebugProtocol.SourceResponse>;
 	getLoadedSources(): Promise<Source[]>;
@@ -504,10 +504,8 @@ export interface IDebugAdapter extends IDisposable {
 	startSession(): Promise<void>;
 	sendMessage(message: DebugProtocol.ProtocolMessage): void;
 	sendResponse(response: DebugProtocol.Response): void;
-	sendRequest(command: string, args: any, clb: (result: DebugProtocol.Response) => void, timeout?: number): void;
+	sendRequest(command: string, args: any, clb: (result: DebugProtocol.Response) => void, timeout?: number): number;
 	stopSession(): Promise<void>;
-	cancelPendingRequests(): void;
-	getPendingRequestIds(): number[];
 }
 
 export interface IDebugAdapterFactory extends ITerminalLauncher {
diff --git a/src/vs/workbench/contrib/debug/common/debugModel.ts b/src/vs/workbench/contrib/debug/common/debugModel.ts
index 8adaccd5b0ff479f458bd8cd366edf8e2d5716e3..c0830fb7e60473ec252707e5a73764b1aa267c9e 100644
--- a/src/vs/workbench/contrib/debug/common/debugModel.ts
+++ b/src/vs/workbench/contrib/debug/common/debugModel.ts
@@ -37,6 +37,7 @@ export class ExpressionContainer implements IExpressionContainer {
 
 	constructor(
 		protected session: IDebugSession | undefined,
+		protected threadId: number | undefined,
 		private _reference: number | undefined,
 		private id: string,
 		public namedVariables: number | undefined = 0,
@@ -85,7 +86,7 @@ export class ExpressionContainer implements IExpressionContainer {
 			for (let i = 0; i < numberOfChunks; i++) {
 				const start = (this.startOfVariables || 0) + i * chunkSize;
 				const count = Math.min(chunkSize, this.indexedVariables - i * chunkSize);
-				children.push(new Variable(this.session, this, this.reference, `[${start}..${start + count - 1}]`, '', '', undefined, count, { kind: 'virtual' }, undefined, true, start));
+				children.push(new Variable(this.session, this.threadId, this, this.reference, `[${start}..${start + count - 1}]`, '', '', undefined, count, { kind: 'virtual' }, undefined, true, start));
 			}
 
 			return children;
@@ -109,12 +110,12 @@ export class ExpressionContainer implements IExpressionContainer {
 	}
 
 	private fetchVariables(start: number | undefined, count: number | undefined, filter: 'indexed' | 'named' | undefined): Promise<Variable[]> {
-		return this.session!.variables(this.reference || 0, filter, start, count).then(response => {
+		return this.session!.variables(this.reference || 0, this.threadId, filter, start, count).then(response => {
 			return response && response.body && response.body.variables
 				? distinct(response.body.variables.filter(v => !!v && isString(v.name)), (v: DebugProtocol.Variable) => v.name).map((v: DebugProtocol.Variable) =>
-					new Variable(this.session, this, v.variablesReference, v.name, v.evaluateName, v.value, v.namedVariables, v.indexedVariables, v.presentationHint, v.type))
+					new Variable(this.session, this.threadId, this, v.variablesReference, v.name, v.evaluateName, v.value, v.namedVariables, v.indexedVariables, v.presentationHint, v.type))
 				: [];
-		}, (e: Error) => [new Variable(this.session, this, 0, e.message, e.message, '', 0, 0, { kind: 'virtual' }, undefined, false)]);
+		}, (e: Error) => [new Variable(this.session, this.threadId, this, 0, e.message, e.message, '', 0, 0, { kind: 'virtual' }, undefined, false)]);
 	}
 
 	// The adapter explicitly sents the children count of an expression only if there are lots of children which should be chunked.
@@ -171,7 +172,7 @@ export class Expression extends ExpressionContainer implements IExpression {
 	public available: boolean;
 
 	constructor(public name: string, id = generateUuid()) {
-		super(undefined, 0, id);
+		super(undefined, undefined, 0, id);
 		this.available = false;
 		// name is not set if the expression is just being added
 		// in that case do not set default value to prevent flashing #14499
@@ -196,6 +197,7 @@ export class Variable extends ExpressionContainer implements IExpression {
 
 	constructor(
 		session: IDebugSession | undefined,
+		threadId: number | undefined,
 		public parent: IExpressionContainer,
 		reference: number | undefined,
 		public name: string,
@@ -208,7 +210,7 @@ export class Variable extends ExpressionContainer implements IExpression {
 		public available = true,
 		startOfVariables = 0
 	) {
-		super(session, reference, `variable:${parent.getId()}:${name}`, namedVariables, indexedVariables, startOfVariables);
+		super(session, threadId, reference, `variable:${parent.getId()}:${name}`, namedVariables, indexedVariables, startOfVariables);
 		this.value = value || '';
 	}
 
@@ -248,7 +250,7 @@ export class Scope extends ExpressionContainer implements IScope {
 		indexedVariables?: number,
 		public range?: IRange
 	) {
-		super(stackFrame.thread.session, reference, `scope:${name}:${index}`, namedVariables, indexedVariables);
+		super(stackFrame.thread.session, stackFrame.thread.threadId, reference, `scope:${name}:${index}`, namedVariables, indexedVariables);
 	}
 
 	toString(): string {
@@ -276,7 +278,7 @@ export class StackFrame implements IStackFrame {
 
 	getScopes(): Promise<IScope[]> {
 		if (!this.scopes) {
-			this.scopes = this.thread.session.scopes(this.frameId).then(response => {
+			this.scopes = this.thread.session.scopes(this.frameId, this.thread.threadId).then(response => {
 				return response && response.body && response.body.scopes ?
 					response.body.scopes.map((rs, index) => new Scope(this, index, rs.name, rs.variablesReference, rs.expensive, rs.namedVariables, rs.indexedVariables,
 						rs.line && rs.column && rs.endLine && rs.endColumn ? new Range(rs.line, rs.column, rs.endLine, rs.endColumn) : undefined)) : [];
diff --git a/src/vs/workbench/contrib/debug/common/replModel.ts b/src/vs/workbench/contrib/debug/common/replModel.ts
index 4d60ecea55a51255322e1a0ce2dc1911eda67944..7808f9e6a0d7838da14734c8a1e898af1b8db281 100644
--- a/src/vs/workbench/contrib/debug/common/replModel.ts
+++ b/src/vs/workbench/contrib/debug/common/replModel.ts
@@ -97,7 +97,7 @@ export class ReplEvaluationInput implements IReplElement {
 
 export class ReplEvaluationResult extends ExpressionContainer implements IReplElement {
 	constructor() {
-		super(undefined, 0, generateUuid());
+		super(undefined, undefined, 0, generateUuid());
 	}
 
 	toString(): string {
diff --git a/src/vs/workbench/contrib/debug/node/debugAdapter.ts b/src/vs/workbench/contrib/debug/node/debugAdapter.ts
index c13409c0603ecbc05d9550b1305ec0c4642a1cfd..84ec75a9c842cee6e16d6ef8cb17e1afca865285 100644
--- a/src/vs/workbench/contrib/debug/node/debugAdapter.ts
+++ b/src/vs/workbench/contrib/debug/node/debugAdapter.ts
@@ -127,8 +127,8 @@ export class SocketDebugAdapter extends StreamDebugAdapter {
 		});
 	}
 
-	stopSession(): Promise<void> {
-
+	async stopSession(): Promise<void> {
+		await this.cancelPendingRequests();
 		if (this.socket) {
 			this.socket.end();
 			this.socket = undefined;
@@ -249,7 +249,7 @@ export class ExecutableDebugAdapter extends StreamDebugAdapter {
 		}
 	}
 
-	stopSession(): Promise<void> {
+	async stopSession(): Promise<void> {
 
 		if (!this.serverProcess) {
 			return Promise.resolve(undefined);
@@ -258,6 +258,7 @@ export class ExecutableDebugAdapter extends StreamDebugAdapter {
 		// when killing a process in windows its child
 		// processes are *not* killed but become root
 		// processes. Therefore we use TASKKILL.EXE
+		await this.cancelPendingRequests();
 		if (platform.isWindows) {
 			return new Promise<void>((c, e) => {
 				const killer = cp.exec(`taskkill /F /T /PID ${this.serverProcess!.pid}`, function (err, stdout, stderr) {
diff --git a/src/vs/workbench/contrib/debug/test/browser/baseDebugView.test.ts b/src/vs/workbench/contrib/debug/test/browser/baseDebugView.test.ts
index dd89032131988333dbfff04c44aa7f35db686b73..48e2c89f0bc2d9c1ae2d16fc7cf3e653e943c449 100644
--- a/src/vs/workbench/contrib/debug/test/browser/baseDebugView.test.ts
+++ b/src/vs/workbench/contrib/debug/test/browser/baseDebugView.test.ts
@@ -76,7 +76,7 @@ suite('Debug - Base Debug View', () => {
 		const stackFrame = new StackFrame(thread, 1, null!, 'app.js', 'normal', { startLineNumber: 1, startColumn: 1, endLineNumber: undefined!, endColumn: undefined! }, 0);
 		const scope = new Scope(stackFrame, 1, 'local', 1, false, 10, 10);
 
-		let variable = new Variable(session, scope, 2, 'foo', 'bar.foo', undefined!, 0, 0, {}, 'string');
+		let variable = new Variable(session, 1, scope, 2, 'foo', 'bar.foo', undefined!, 0, 0, {}, 'string');
 		let expression = $('.');
 		let name = $('.');
 		let value = $('.');
@@ -104,7 +104,7 @@ suite('Debug - Base Debug View', () => {
 		assert.ok(value.querySelector('a'));
 		assert.equal(value.querySelector('a')!.textContent, variable.value);
 
-		variable = new Variable(session, scope, 2, 'console', 'console', '5', 0, 0, { kind: 'virtual' });
+		variable = new Variable(session, 1, scope, 2, 'console', 'console', '5', 0, 0, { kind: 'virtual' });
 		expression = $('.');
 		name = $('.');
 		value = $('.');
diff --git a/src/vs/workbench/contrib/debug/test/common/mockDebug.ts b/src/vs/workbench/contrib/debug/test/common/mockDebug.ts
index f70b8aee729120aa595862f3d0efc70afca0c6ff..0abec14fb2100151d3fdb525b654ec42a32b37cb 100644
--- a/src/vs/workbench/contrib/debug/test/common/mockDebug.ts
+++ b/src/vs/workbench/contrib/debug/test/common/mockDebug.ts
@@ -264,7 +264,7 @@ export class MockSession implements IDebugSession {
 	scopes(frameId: number): Promise<DebugProtocol.ScopesResponse> {
 		throw new Error('Method not implemented.');
 	}
-	variables(variablesReference: number, filter: 'indexed' | 'named', start: number, count: number): Promise<DebugProtocol.VariablesResponse> {
+	variables(variablesReference: number, threadId: number | undefined, filter: 'indexed' | 'named', start: number, count: number): Promise<DebugProtocol.VariablesResponse> {
 		throw new Error('Method not implemented.');
 	}
 	evaluate(expression: string, frameId: number, context?: string): Promise<DebugProtocol.EvaluateResponse> {