Fix terminal object leaking

src/common/CoreTerminal.ts

@@ -86,7 +86,7 @@ export abstract class CoreTerminal extends Disposable implements ICoreTerminal {
     this._instantiationService.setService(IBufferService, this._bufferService);
     this._logService = this._instantiationService.createInstance(LogService);
     this._instantiationService.setService(ILogService, this._logService);
-    this._coreService = this._instantiationService.createInstance(CoreService, () => this.scrollToBottom());
+    this._coreService = this.register(this._instantiationService.createInstance(CoreService, () => this.scrollToBottom()));
     this._instantiationService.setService(ICoreService, this._coreService);
     this._coreMouseService = this._instantiationService.createInstance(CoreMouseService);
     this._instantiationService.setService(ICoreMouseService, this._coreMouseService);

src/common/Lifecycle.ts

@@ -28,9 +28,11 @@ export abstract class Disposable implements IDisposable {
   /**
    * Registers a disposable object.
    * @param d The disposable to register.
+   * @returns The disposable.
    */
-  public register<T extends IDisposable>(d: T): void {
+  public register<T extends IDisposable>(d: T): T {
     this._disposables.push(d);
+    return d;
   }
 
   /**

src/common/services/CoreService.ts

@@ -7,6 +7,7 @@ import { ICoreService, ILogService, IOptionsService, IBufferService } from 'comm
 import { EventEmitter, IEvent } from 'common/EventEmitter';
 import { IDecPrivateModes, IModes } from 'common/Types';
 import { clone } from 'common/Clone';
+import { Disposable } from 'common/Lifecycle';
 
 const DEFAULT_MODES: IModes = Object.freeze({
   insertMode: false
@@ -22,7 +23,7 @@ const DEFAULT_DEC_PRIVATE_MODES: IDecPrivateModes = Object.freeze({
   wraparound: true // defaults: xterm - true, vt100 - false
 });
 
-export class CoreService implements ICoreService {
+export class CoreService extends Disposable implements ICoreService {
   public serviceBrand: any;
 
   public isCursorInitialized: boolean = false;
@@ -30,20 +31,26 @@ export class CoreService implements ICoreService {
   public modes: IModes;
   public decPrivateModes: IDecPrivateModes;
 
-  private _onData = new EventEmitter<string>();
+  // Circular dependency, this must be unset or memory will leak after Terminal.dispose
+  private _scrollToBottom: (() => void) | undefined;
+
+  private _onData = this.register(new EventEmitter<string>());
   public get onData(): IEvent<string> { return this._onData.event; }
-  private _onUserInput = new EventEmitter<void>();
+  private _onUserInput = this.register(new EventEmitter<void>());
   public get onUserInput(): IEvent<void> { return this._onUserInput.event; }
-  private _onBinary = new EventEmitter<string>();
+  private _onBinary = this.register(new EventEmitter<string>());
   public get onBinary(): IEvent<string> { return this._onBinary.event; }
 
   constructor(
     // TODO: Move this into a service
-    private readonly _scrollToBottom: () => void,
+    scrollToBottom: () => void,
     @IBufferService private readonly _bufferService: IBufferService,
     @ILogService private readonly _logService: ILogService,
     @IOptionsService private readonly _optionsService: IOptionsService
   ) {
+    super();
+    this._scrollToBottom = scrollToBottom;
+    this.register({ dispose: () => this._scrollToBottom = undefined });
     this.modes = clone(DEFAULT_MODES);
     this.decPrivateModes = clone(DEFAULT_DEC_PRIVATE_MODES);
   }
@@ -62,7 +69,7 @@ export class CoreService implements ICoreService {
     // Input is being sent to the terminal, the terminal should focus the prompt.
     const buffer = this._bufferService.buffer;
     if (buffer.ybase !== buffer.ydisp) {
-      this._scrollToBottom();
+      this._scrollToBottom!();
     }
 
     // Fire onUserInput so listeners can react as well (eg. clear selection)