| // Copyright 2014 The Chromium Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| #ifndef COMPONENTS_TIMERS_ALARM_TIMER_CHROMEOS_H_ |
| #define COMPONENTS_TIMERS_ALARM_TIMER_CHROMEOS_H_ |
| |
| #include <memory> |
| |
| #include "base/files/file_descriptor_watcher_posix.h" |
| #include "base/macros.h" |
| #include "base/memory/scoped_refptr.h" |
| #include "base/memory/weak_ptr.h" |
| #include "base/threading/sequenced_task_runner_handle.h" |
| #include "base/time/time.h" |
| #include "base/timer/timer.h" |
| |
| namespace base { |
| struct PendingTask; |
| } |
| |
| namespace timers { |
| // The class implements a timer that is capable of waking the system up from a |
| // suspended state. For example, this is useful for running tasks that are |
| // needed for maintaining network connectivity, like sending heartbeat messages. |
| // Currently, this feature is only available on Chrome OS systems running linux |
| // version 3.11 or higher. On all other platforms, the SimpleAlarmTimer behaves |
| // exactly the same way as a regular Timer. |
| // |
| // A SimpleAlarmTimer instance can only be used from the sequence on which it |
| // was instantiated. Start() and Stop() must be called from a thread that |
| // supports FileDescriptorWatcher. |
| // |
| // A SimpleAlarmTimer only fires once but remembers the task that it was given |
| // even after it has fired. Useful if you want to run the same task multiple |
| // times but not at a regular interval. |
| class SimpleAlarmTimer : public base::RetainingOneShotTimer { |
| public: |
| SimpleAlarmTimer(); |
| ~SimpleAlarmTimer() override; |
| |
| // Timer overrides. |
| void Stop() override; |
| void Reset() override; |
| |
| private: |
| // Called when |alarm_fd_| is readable without blocking. Reads data from |
| // |alarm_fd_| and calls OnTimerFired(). |
| void OnAlarmFdReadableWithoutBlocking(); |
| |
| // Called when the timer fires. Runs the callback. |
| void OnTimerFired(); |
| |
| // Tracks whether the timer has the ability to wake the system up from |
| // suspend. This is a runtime check because we won't know if the system |
| // supports being woken up from suspend until the constructor actually tries |
| // to set it up. |
| bool CanWakeFromSuspend() const; |
| |
| // Timer file descriptor. |
| const int alarm_fd_; |
| |
| // Watches |alarm_fd_|. |
| std::unique_ptr<base::FileDescriptorWatcher::Controller> alarm_fd_watcher_; |
| |
| // Posts tasks to the sequence on which this AlarmTimer was instantiated. |
| const scoped_refptr<base::SequencedTaskRunner> origin_task_runner_ = |
| base::SequencedTaskRunnerHandle::Get(); |
| |
| // Keeps track of the user task we want to run. A new one is constructed every |
| // time Reset() is called. |
| std::unique_ptr<base::PendingTask> pending_task_; |
| |
| // Used to invalidate pending callbacks. |
| base::WeakPtrFactory<SimpleAlarmTimer> weak_factory_; |
| |
| DISALLOW_COPY_AND_ASSIGN(SimpleAlarmTimer); |
| }; |
| |
| } // namespace timers |
| |
| #endif // COMPONENTS_TIMERS_ALARM_TIMER_CHROMEOS_H_ |