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/*
* 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
* once.
*
* Warning: MessageLoopThread must be running when any task is scheduled or
* being executed
*/
class OnceTimer final {
public:
OnceTimer() {}
~OnceTimer();
/**
* Schedule a delayed 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 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 delay delay for the task to be executed
* @return true iff task is scheduled successfully
*/
bool Schedule(const base::WeakPtr<MessageLoopThread>& thread,
const base::Location& from_here, base::OnceClosure task,
base::TimeDelta delay);
/**
* 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::CancelableOnceClosure task_wrapper_;
base::OnceClosure task_;
base::TimeDelta delay_;
mutable std::recursive_mutex api_mutex_;
void CancelHelper(std::promise<void> promise);
void CancelClosure(std::promise<void> promise);
void RunTask();
DISALLOW_COPY_AND_ASSIGN(OnceTimer);
};
} // namespace common
} // namespace bluetooth