ios/web/init/web_main_loop.h

// Copyright 2014 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef IOS_WEB_INIT_WEB_MAIN_LOOP_H_
#define IOS_WEB_INIT_WEB_MAIN_LOOP_H_

#include <memory>

#include "base/functional/callback_helpers.h"

namespace web {
class CookieNotificationBridge;
class WebMainParts;
class WebThreadImpl;
class WebSubThread;

// Implements the main web loop stages called from WebMainRunner.
// See comments in web_main_parts.h for additional info.
class WebMainLoop {
 public:
  explicit WebMainLoop();

  WebMainLoop(const WebMainLoop&) = delete;
  WebMainLoop& operator=(const WebMainLoop&) = delete;

  virtual ~WebMainLoop();

  void Init();

  void EarlyInitialization();
  void CreateMainMessageLoop();

  // Creates and starts running the tasks needed to complete startup.
  void CreateStartupTasks();

  // Performs the shutdown sequence, starting with PostMainMessageLoopRun
  // through stopping threads to PostDestroyThreads.
  void ShutdownThreadsAndCleanUp();

  int GetResultCode() const { return result_code_; }

 private:
  void InitializeMainThread();

  // Called just before creating the threads
  int PreCreateThreads();

  // Creates all secondary threads.
  int CreateThreads();

  // Called after creating the threads
  int PostCreateThreads();

  // Called right after the web threads have been started.
  int WebThreadsStarted();

  // Called just before attaching to the main message loop.
  int PreMainMessageLoopRun();

  // Members initialized on construction ---------------------------------------
  int result_code_;
  // True if the non-UI threads were created.
  bool created_threads_;

  // Members initialized in `CreateMainMessageLoop()` --------------------------
  // The SingleThreadTaskExecutor and NetworkChangeNotifier are not owned by the
  // WebMainLoop but still need to be destroyed in correct order so use
  // ScopedClosureRunner.
  base::ScopedClosureRunner destroy_task_executor_;
  base::ScopedClosureRunner destroy_network_change_notifier_;

  // Destroy parts_ before main_message_loop_ (required) and before other
  // classes constructed in web (but after main_thread_).
  std::unique_ptr<WebMainParts> parts_;

  // Members initialized in `InitializeMainThread()` ---------------------------
  // This must get destroyed after other threads that are created in parts_.
  std::unique_ptr<WebThreadImpl> main_thread_;

  // Members initialized in `CreateThreads()` ------------------------
  std::unique_ptr<WebSubThread> io_thread_;

  // Members initialized in `WebThreadsStarted()` --------------------------
  std::unique_ptr<CookieNotificationBridge> cookie_notification_bridge_;
};

}  // namespace web

#endif  // IOS_WEB_INIT_WEB_MAIN_LOOP_H_