beware of sync/async promises

related to #60163

src/vs/base/common/lifecycle.ts

@@ -80,7 +80,7 @@ export abstract class ReferenceCollection<T> {
 		const { object } = reference;
 		const dispose = once(() => {
 			if (--reference.counter === 0) {
-				this.destroyReferencedObject(reference.object);
+				this.destroyReferencedObject(key, reference.object);
 				delete this.references[key];
 			}
 		});
@@ -91,7 +91,7 @@ export abstract class ReferenceCollection<T> {
 	}
 
 	protected abstract createReferencedObject(key: string): T;
-	protected abstract destroyReferencedObject(object: T): void;
+	protected abstract destroyReferencedObject(key: string, object: T): void;
 }
 
 export class ImmortalReference<T> implements IReference<T> {

src/vs/base/test/common/lifecycle.test.ts

@@ -54,7 +54,7 @@ suite('Reference Collection', () => {
 		private _count = 0;
 		get count() { return this._count; }
 		protected createReferencedObject(key: string): number { this._count++; return key.length; }
-		protected destroyReferencedObject(object: number): void { this._count--; }
+		protected destroyReferencedObject(key: string, object: number): void { this._count--; }
 	}
 
 	test('simple', () => {

src/vs/workbench/services/textmodelResolver/common/textModelResolverService.ts

@@ -21,6 +21,7 @@ import { IFileService } from 'vs/platform/files/common/files';
 class ResourceModelCollection extends ReferenceCollection<TPromise<ITextEditorModel>> {
 
 	private providers: { [scheme: string]: ITextModelContentProvider[] } = Object.create(null);
+	private modelsToDispose = new Set<string>();
 
 	constructor(
 		@IInstantiationService private instantiationService: IInstantiationService,
@@ -31,6 +32,8 @@ class ResourceModelCollection extends ReferenceCollection<TPromise<ITextEditorMo
 	}
 
 	createReferencedObject(key: string): TPromise<ITextEditorModel> {
+		this.modelsToDispose.delete(key);
+
 		const resource = URI.parse(key);
 		if (this.fileService.canHandleResource(resource)) {
 			return this.textFileService.models.loadOrCreate(resource, { reason: LoadReason.REFERENCE });
@@ -39,12 +42,16 @@ class ResourceModelCollection extends ReferenceCollection<TPromise<ITextEditorMo
 		return this.resolveTextModelContent(key).then(() => this.instantiationService.createInstance(ResourceEditorModel, resource));
 	}
 
-	destroyReferencedObject(modelPromise: TPromise<ITextEditorModel>): void {
+	destroyReferencedObject(key: string, modelPromise: TPromise<ITextEditorModel>): void {
+		this.modelsToDispose.add(key);
+
 		modelPromise.then(model => {
-			if (model instanceof TextFileEditorModel) {
-				this.textFileService.models.disposeModel(model);
-			} else {
-				model.dispose();
+			if (this.modelsToDispose.has(key)) {
+				if (model instanceof TextFileEditorModel) {
+					this.textFileService.models.disposeModel(model);
+				} else {
+					model.dispose();
+				}
 			}
 		}, err => {
 			// ignore