VSCode源码分析 - 进程通信

目录

进程通信

主进程

src/vs/code/electron-main/main.ts

main.ts在启动应用后就创建了一个主进程 main process，它可以通过electron中的一些模块直接与原生GUI交互。

  1. server = await serve(environmentService.mainIPCHandle);
  2. once(lifecycleService.onWillShutdown)(() => server.dispose());

渲染进程

仅启动主进程并不能给你的应用创建应用窗口。窗口是通过main文件里的主进程调用叫BrowserWindow的模块创建的。

主进程与渲染进程之间的通信

在electron中，主进程与渲染进程有很多通信的方法。比如ipcRenderer和ipcMain，还可以在渲染进程使用remote模块。

ipcMain & ipcRenderer

  • 主进程：ipcMain
  • 渲染进程：ipcRenderer

ipcMain模块和ipcRenderer是类EventEmitter的实例。

在主进程中使用ipcMain接收渲染线程发送过来的异步或同步消息，发送过来的消息将触发事件。

在渲染进程中使用ipcRenderer向主进程发送同步或异步消息，也可以接收到主进程的消息。

  • 发送消息，事件名为 channel .
  • 回应同步消息, 你可以设置 event.returnValue .
  • 回应异步消息, 你可以使用 event.sender.send(…)

创建IPC服务 src/vs/base/parts/ipc/node/ipc.net.ts

这里返回一个promise对象，成功则createServer

  1. export function serve(hook: any): Promise<Server> {
  2.     return new Promise<Server>((c, e) => {
  3.         const server = createServer();
  5.         server.on('error', e);
  6.         server.listen(hook, () => {
  7.             server.removeListener('error', e);
  8.             c(new Server(server));
  9.         });
  10.     });
  11. }

创建信道

src/vs/code/electron-main/app.ts

  • mainIpcServer

    • launchChannel

  • electronIpcServer

    • updateChannel
    • issueChannel
    • workspacesChannel
    • windowsChannel
    • menubarChannel
    • urlChannel
    • storageChannel
    • logLevelChannel
  1. private openFirstWindow(accessor: ServicesAccessor, electronIpcServer: ElectronIPCServer, sharedProcessClient: Promise<Client<string>>): ICodeWindow[] {
  3.         // Register more Main IPC services
  4.         const launchService = accessor.get(ILaunchService);
  5.         const launchChannel = new LaunchChannel(launchService);
  6.         this.mainIpcServer.registerChannel('launch', launchChannel);
  8.         // Register more Electron IPC services
  9.         const updateService = accessor.get(IUpdateService);
  10.         const updateChannel = new UpdateChannel(updateService);
  11.         electronIpcServer.registerChannel('update', updateChannel);
  13.         const issueService = accessor.get(IIssueService);
  14.         const issueChannel = new IssueChannel(issueService);
  15.         electronIpcServer.registerChannel('issue', issueChannel);
  17.         const workspacesService = accessor.get(IWorkspacesMainService);
  18.         const workspacesChannel = new WorkspacesChannel(workspacesService);
  19.         electronIpcServer.registerChannel('workspaces', workspacesChannel);
  21.         const windowsService = accessor.get(IWindowsService);
  22.         const windowsChannel = new WindowsChannel(windowsService);
  23.         electronIpcServer.registerChannel('windows', windowsChannel);
  24.         sharedProcessClient.then(client => client.registerChannel('windows', windowsChannel));
  26.         const menubarService = accessor.get(IMenubarService);
  27.         const menubarChannel = new MenubarChannel(menubarService);
  28.         electronIpcServer.registerChannel('menubar', menubarChannel);
  30.         const urlService = accessor.get(IURLService);
  31.         const urlChannel = new URLServiceChannel(urlService);
  32.         electronIpcServer.registerChannel('url', urlChannel);
  34.         const storageMainService = accessor.get(IStorageMainService);
  35.         const storageChannel = this._register(new GlobalStorageDatabaseChannel(this.logService, storageMainService));
  36.         electronIpcServer.registerChannel('storage', storageChannel);
  38.         // Log level management
  39.         const logLevelChannel = new LogLevelSetterChannel(accessor.get(ILogService));
  40.         electronIpcServer.registerChannel('loglevel', logLevelChannel);
  41.         sharedProcessClient.then(client => client.registerChannel('loglevel', logLevelChannel));
  43.         ...
  45.         // default: read paths from cli
  46.         return windowsMainService.open({
  47.             context,
  48.             cli: args,
  49.             forceNewWindow: args['new-window'] || (!hasCliArgs && args['unity-launch']),
  50.             diffMode: args.diff,
  51.             noRecentEntry,
  52.             waitMarkerFileURI,
  53.             gotoLineMode: args.goto,
  54.             initialStartup: true
  55.         });
  56.     }

每一个信道，内部实现两个方法 listen和call

例如：src/vs/platform/localizations/node/localizationsIpc.ts

构造函数绑定事件

  1. export class LocalizationsChannel implements IServerChannel {
  3.     onDidLanguagesChange: Event<void>;
  5.     constructor(private service: ILocalizationsService) {
  6.         this.onDidLanguagesChange = Event.buffer(service.onDidLanguagesChange, true);
  7.     }
  9.     listen(_: unknown, event: string): Event<any> {
  10.         switch (event) {
  11.             case 'onDidLanguagesChange': return this.onDidLanguagesChange;
  12.         }
  14.         throw new Error(`Event not found: ${event}`);
  15.     }
  17.     call(_: unknown, command: string, arg?: any): Promise<any> {
  18.         switch (command) {
  19.             case 'getLanguageIds': return this.service.getLanguageIds(arg);
  20.         }
  22.         throw new Error(`Call not found: ${command}`);
  23.     }
  24. }