fix: use a barrier instead of an event

src/vscode-services/extHost.ts

@@ -40,7 +40,7 @@ import { InstantiationType, registerSingleton } from 'vs/platform/instantiation/
 import { IMessagePassingProtocol } from 'vs/base/parts/ipc/common/ipc'
 import { BufferedEmitter } from 'vs/base/parts/ipc/common/ipc.net'
 import { VSBuffer } from 'vs/base/common/buffer'
-import { Emitter, Event } from 'vs/base/common/event'
+import { Event } from 'vs/base/common/event'
 import { RPCProtocol } from 'vs/workbench/services/extensions/common/rpcProtocol'
 import { ExtHostConsumerFileSystem, IExtHostConsumerFileSystem } from 'vs/workbench/api/common/extHostFileSystemConsumer'
 import { IExtHostInitDataService } from 'vs/workbench/api/common/extHostInitDataService'
@@ -84,6 +84,7 @@ import 'vs/workbench/api/browser/mainThreadSaveParticipant'
 import 'vs/workbench/api/browser/mainThreadTreeViews'
 import 'vs/workbench/api/browser/mainThreadStorage'
 import * as errors from 'vs/base/common/errors'
+import { Barrier } from 'vs/base/common/async'
 import { unsupported } from '../tools'
 
 const original = MainThreadMessageService.prototype.$showMessage
@@ -421,13 +422,15 @@ let configProvider: ExtHostConfigProvider | undefined
 
 let initializePromise: Promise<void> | undefined
 
-const extHostInitializedEmitter = new Emitter<void>()
-export const onExtHostInitialized: Event<void> = extHostInitializedEmitter.event
+const extHostInitializedBarrier = new Barrier()
+export function onExtHostInitialized (fct: () => void): void {
+  void extHostInitializedBarrier.wait().then(fct)
+}
 
 async function _initialize (): Promise<void> {
   extHostServices = await createExtHostServices()
   configProvider = await extHostServices.extHostConfiguration.getConfigProvider()
-  extHostInitializedEmitter.fire()
+  extHostInitializedBarrier.open()
 }
 
 export async function initialize (): Promise<void> {