eclipse-theiaGH-6499: Explicitly close the socket onStop in electron

Otherwise, the channels will be closed with a `checkAliveTimeout` delay
in the electron application, when refreshing the browser window.

Closes: eclipse-theia#6499

Signed-off-by: Akos Kitta <kittaakos@typefox.io>

dev-packages/application-manager/src/generator/frontend-generator.ts

@@ -69,7 +69,7 @@ require('reflect-metadata');
 const { Container } = require('inversify');
 const { FrontendApplication } = require('@theia/core/lib/browser');
 const { frontendApplicationModule } = require('@theia/core/lib/browser/frontend-application-module');
-const { messagingFrontendModule } = require('@theia/core/lib/browser/messaging/messaging-frontend-module');
+const { messagingFrontendModule } = require('@theia/core/lib/${this.pck.isBrowser() ? 'browser/messaging/messaging-frontend-module' : 'electron-browser/messaging/electron-messaging-frontend-module'}');
 const { loggerFrontendModule } = require('@theia/core/lib/browser/logger-frontend-module');
 const { ThemeService } = require('@theia/core/lib/browser/theming');
 const { FrontendApplicationConfigProvider } = require('@theia/core/lib/browser/frontend-application-config-provider');

packages/core/src/common/messaging/web-socket-channel.ts

@@ -79,6 +79,10 @@ export class WebSocketChannel implements IWebSocket {
     }
 
     close(code: number = 1000, reason: string = ''): void {
+        if (this.closing) {
+            // Do not try to close the channel if it is already closing.
+            return;
+        }
         this.checkNotDisposed();
         this.doSend(JSON.stringify(<WebSocketChannel.CloseMessage>{
             kind: 'close',

packages/core/src/electron-browser/messaging/electron-messaging-frontend-module.ts

@@ -0,0 +1,26 @@
+/********************************************************************************
+ * Copyright (C) 2019 TypeFox and others.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Eclipse Public License v. 2.0 which is available at
+ * http://www.eclipse.org/legal/epl-2.0.
+ *
+ * This Source Code may also be made available under the following Secondary
+ * Licenses when the conditions for such availability set forth in the Eclipse
+ * Public License v. 2.0 are satisfied: GNU General Public License, version 2
+ * with the GNU Classpath Exception which is available at
+ * https://www.gnu.org/software/classpath/license.html.
+ *
+ * SPDX-License-Identifier: EPL-2.0 OR GPL-2.0 WITH Classpath-exception-2.0
+ ********************************************************************************/
+
+import { ContainerModule } from 'inversify';
+import { FrontendApplicationContribution } from '../../browser/frontend-application';
+import { WebSocketConnectionProvider } from '../../browser/messaging/ws-connection-provider';
+import { ElectronWebSocketConnectionProvider } from './electron-ws-connection-provider';
+
+export const messagingFrontendModule = new ContainerModule(bind => {
+    bind(ElectronWebSocketConnectionProvider).toSelf().inSingletonScope();
+    bind(FrontendApplicationContribution).toService(ElectronWebSocketConnectionProvider);
+    bind(WebSocketConnectionProvider).toService(ElectronWebSocketConnectionProvider);
+});

packages/core/src/electron-browser/messaging/electron-ws-connection-provider.ts

@@ -0,0 +1,47 @@
+/********************************************************************************
+ * Copyright (C) 2019 TypeFox and others.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Eclipse Public License v. 2.0 which is available at
+ * http://www.eclipse.org/legal/epl-2.0.
+ *
+ * This Source Code may also be made available under the following Secondary
+ * Licenses when the conditions for such availability set forth in the Eclipse
+ * Public License v. 2.0 are satisfied: GNU General Public License, version 2
+ * with the GNU Classpath Exception which is available at
+ * https://www.gnu.org/software/classpath/license.html.
+ *
+ * SPDX-License-Identifier: EPL-2.0 OR GPL-2.0 WITH Classpath-exception-2.0
+ ********************************************************************************/
+
+import { injectable } from 'inversify';
+import { WebSocketChannel } from '../../common/messaging/web-socket-channel';
+import { WebSocketConnectionProvider, WebSocketOptions } from '../../browser/messaging/ws-connection-provider';
+import { FrontendApplicationContribution } from '../../browser/frontend-application';
+
+@injectable()
+export class ElectronWebSocketConnectionProvider extends WebSocketConnectionProvider implements FrontendApplicationContribution {
+
+    /**
+     * Do not try to reconnect when the frontend application is stopping. The browser is navigating away from this page.
+     */
+    protected stopping = false;
+
+    onStop(): void {
+        this.stopping = true;
+        // Close the websocket connection `onStop`. Otherwise, the channels will be closed with 30 sec (`MessagingContribution#checkAliveTimeout`) delay.
+        // https://github.com/eclipse-theia/theia/issues/6499
+        for (const channel of [...this.channels.values()]) {
+            // `1001` indicates that an endpoint is "going away", such as a server going down or a browser having navigated away from a page.
+            // But we cannot use `1001`: https://github.com/TypeFox/vscode-ws-jsonrpc/issues/15
+            channel.close(1000, 'The frontend is "going away"...');
+        }
+    }
+
+    openChannel(path: string, handler: (channel: WebSocketChannel) => void, options?: WebSocketOptions): void {
+        if (!this.stopping) {
+            super.openChannel(path, handler, options);
+        }
+    }
+
+}

packages/core/src/node/messaging/messaging-contribution.ts

@@ -127,8 +127,12 @@ export class MessagingContribution implements BackendApplicationContribution, Me
                     const channel = this.createChannel(id, socket);
                     if (channelHandlers.route(path, channel)) {
                         channel.ready();
+                        console.debug(`Opening channel for service path '${path}'. [ID: ${id}]`);
                         channels.set(id, channel);
-                        channel.onClose(() => channels.delete(id));
+                        channel.onClose(() => {
+                            console.debug(`Closing channel on service path '${path}'. [ID: ${id}]`);
+                            channels.delete(id);
+                        });
                     } else {
                         console.error('Cannot find a service for the path: ' + path);
                     }

packages/search-in-workspace/src/browser/search-in-workspace-frontend-module.ts

@@ -18,7 +18,7 @@ import '../../src/browser/styles/index.css';
 
 import { ContainerModule, interfaces } from 'inversify';
 import { SearchInWorkspaceService, SearchInWorkspaceClientImpl } from './search-in-workspace-service';
-import { SearchInWorkspaceServer } from '../common/search-in-workspace-interface';
+import { SearchInWorkspaceServer, SIW_WS_PATH } from '../common/search-in-workspace-interface';
 import { WebSocketConnectionProvider, WidgetFactory, createTreeContainer, TreeWidget, bindViewContribution, FrontendApplicationContribution } from '@theia/core/lib/browser';
 import { ResourceResolver } from '@theia/core';
 import { SearchInWorkspaceWidget } from './search-in-workspace-widget';
@@ -51,7 +51,7 @@ export default new ContainerModule(bind => {
     // The object to call methods on the backend.
     bind(SearchInWorkspaceServer).toDynamicValue(ctx => {
         const client = ctx.container.get(SearchInWorkspaceClientImpl);
-        return WebSocketConnectionProvider.createProxy(ctx.container, '/search-in-workspace', client);
+        return WebSocketConnectionProvider.createProxy(ctx.container, SIW_WS_PATH, client);
     }).inSingletonScope();
 
     bind(InMemoryTextResourceResolver).toSelf().inSingletonScope();

packages/search-in-workspace/src/common/search-in-workspace-interface.ts

@@ -116,6 +116,7 @@ export interface SearchInWorkspaceClient {
     onDone(searchId: number, error?: string): void;
 }
 
+export const SIW_WS_PATH = '/services/search-in-workspace';
 export const SearchInWorkspaceServer = Symbol('SearchInWorkspaceServer');
 export interface SearchInWorkspaceServer extends JsonRpcServer<SearchInWorkspaceClient> {
     /**

packages/search-in-workspace/src/node/search-in-workspace-backend-module.ts

@@ -16,20 +16,18 @@
 
 import { ContainerModule } from 'inversify';
 import { ConnectionHandler, JsonRpcConnectionHandler } from '@theia/core/lib/common';
-import { SearchInWorkspaceServer, SearchInWorkspaceClient } from '../common/search-in-workspace-interface';
+import { SearchInWorkspaceServer, SearchInWorkspaceClient, SIW_WS_PATH } from '../common/search-in-workspace-interface';
 import { RipgrepSearchInWorkspaceServer, RgPath } from './ripgrep-search-in-workspace-server';
 import { rgPath } from 'vscode-ripgrep';
 
 export default new ContainerModule(bind => {
     bind(SearchInWorkspaceServer).to(RipgrepSearchInWorkspaceServer);
     bind(ConnectionHandler).toDynamicValue(ctx =>
-        new JsonRpcConnectionHandler<SearchInWorkspaceClient>
-            ('/search-in-workspace', client => {
-                const server = ctx.container.get<SearchInWorkspaceServer>(SearchInWorkspaceServer);
-                server.setClient(client);
-                client.onDidCloseConnection(() => server.dispose());
-                return server;
-            })
-    );
+        new JsonRpcConnectionHandler<SearchInWorkspaceClient>(SIW_WS_PATH, client => {
+            const server = ctx.container.get<SearchInWorkspaceServer>(SearchInWorkspaceServer);
+            server.setClient(client);
+            client.onDidCloseConnection(() => server.dispose());
+            return server;
+        }));
     bind(RgPath).toConstantValue(rgPath);
 });