1 // Copyright 2013 The Chromium Authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style license that can be 3 // found in the LICENSE file. 4 5 #ifndef CONTENT_BROWSER_STARTUP_TASK_RUNNER_H_ 6 #define CONTENT_BROWSER_STARTUP_TASK_RUNNER_H_ 7 8 #include <list> 9 10 #include "base/callback.h" 11 #include "base/memory/ref_counted.h" 12 #include "base/single_thread_task_runner.h" 13 14 #include "build/build_config.h" 15 16 #include "content/public/browser/browser_main_runner.h" 17 18 namespace content { 19 20 // A startup task is a void function returning the status on completion. 21 // a status of > 0 indicates a failure, and that no further startup tasks should 22 // be run. 23 typedef base::Callback<int(void)> StartupTask; 24 25 // This class runs startup tasks. The tasks are either run immediately inline, 26 // or are queued one at a time on the UI thread's message loop. If the events 27 // are queued, UI events that are received during startup will be acted upon 28 // between startup tasks. The motivation for this is that, on targets where the 29 // UI is already started, it allows us to keep the UI responsive during startup. 30 // 31 // Note that this differs from a SingleThreadedTaskRunner in that there may be 32 // no opportunity to handle UI events between the tasks of a 33 // SingleThreadedTaskRunner. 34 35 class CONTENT_EXPORT StartupTaskRunner 36 : public base::RefCounted<StartupTaskRunner> { 37 38 public: 39 // Constructor: Note that |startup_complete_callback| is optional. If it is 40 // not null it will be called once all the startup tasks have run. 41 StartupTaskRunner(bool browser_may_start_asynchronously, 42 base::Callback<void(int)> startup_complete_callback, 43 scoped_refptr<base::SingleThreadTaskRunner> proxy); 44 45 // Add a task to the queue of startup tasks to be run. 46 virtual void AddTask(StartupTask& callback); 47 48 // Start running the tasks. 49 virtual void StartRunningTasks(); 50 51 private: 52 friend class base::RefCounted<StartupTaskRunner>; 53 virtual ~StartupTaskRunner(); 54 55 std::list<StartupTask> task_list_; 56 void WrappedTask(); 57 58 const bool asynchronous_startup_; 59 base::Callback<void(int)> startup_complete_callback_; 60 scoped_refptr<base::SingleThreadTaskRunner> proxy_; 61 62 DISALLOW_COPY_AND_ASSIGN(StartupTaskRunner); 63 }; 64 65 } // namespace content 66 #endif // CONTENT_BROWSER_STARTUP_TASK_RUNNER_H_ 67
