You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.

93 lines
2.7 KiB

/*
* Copyright 2018 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#pragma once
#include <base/bind.h>
#include <base/cancelable_callback.h>
#include <base/location.h>
#include <future>
namespace bluetooth {
namespace common {
class MessageLoopThread;
/**
* An alarm clock that posts a delayed task to a specified MessageLoopThread
* periodically.
*
* Warning: MessageLoopThread must be running when any task is scheduled or
* being executed
*/
class RepeatingTimer final {
public:
RepeatingTimer() : expected_time_next_task_us_(0) {}
~RepeatingTimer();
/**
* Schedule a delayed periodic task to the MessageLoopThread. Only one task
* can be scheduled at a time. If another task is scheduled, it will cancel
* the previous task synchronously and schedule the new periodic task; this
* blocks until the previous task is cancelled.
*
* @param thread thread to run the task
* @param from_here location where this task is originated
* @param task task created through base::Bind()
* @param period period for the task to be executed
* @return true iff task is scheduled successfully
*/
bool SchedulePeriodic(const base::WeakPtr<MessageLoopThread>& thread,
const base::Location& from_here,
base::RepeatingClosure task, base::TimeDelta period);
/**
* Post an event which cancels the current task asynchronously
*/
void Cancel();
/**
* Post an event which cancels the current task and wait for the cancellation
* to be completed
*/
void CancelAndWait();
/**
* Returns true when there is a pending task scheduled on a running thread,
* otherwise false.
*/
bool IsScheduled() const;
private:
base::WeakPtr<MessageLoopThread> message_loop_thread_;
base::CancelableClosure task_wrapper_;
base::RepeatingClosure task_;
base::TimeDelta period_;
uint64_t expected_time_next_task_us_; // Using clock boot time in time_util.h
mutable std::recursive_mutex api_mutex_;
void CancelHelper(std::promise<void> promise);
void CancelClosure(std::promise<void> promise);
void RunTask();
DISALLOW_COPY_AND_ASSIGN(RepeatingTimer);
};
} // namespace common
} // namespace bluetooth