mirror of
https://github.com/TomHarte/CLK.git
synced 2024-11-23 03:32:32 +00:00
66 lines
1.6 KiB
C++
66 lines
1.6 KiB
C++
//
|
|
// BestEffortUpdater.hpp
|
|
// Clock Signal
|
|
//
|
|
// Created by Thomas Harte on 04/10/2017.
|
|
// Copyright © 2017 Thomas Harte. All rights reserved.
|
|
//
|
|
|
|
#ifndef BestEffortUpdater_hpp
|
|
#define BestEffortUpdater_hpp
|
|
|
|
#include <atomic>
|
|
#include <chrono>
|
|
|
|
#include "AsyncTaskQueue.hpp"
|
|
|
|
namespace Concurrency {
|
|
|
|
/*!
|
|
Accepts timing cues from multiple threads and ensures that a delegate receives calls to total
|
|
a certain number of cycles per second, that those calls are strictly serialised, and that no
|
|
backlog of calls accrues.
|
|
|
|
No guarantees about the thread that the delegate will be called on are made.
|
|
*/
|
|
class BestEffortUpdater {
|
|
public:
|
|
BestEffortUpdater();
|
|
|
|
/// A delegate receives timing cues.
|
|
struct Delegate {
|
|
virtual void update(BestEffortUpdater *updater, int cycles, bool did_skip_previous_update) = 0;
|
|
};
|
|
|
|
/// Sets the current delegate.
|
|
void set_delegate(Delegate *);
|
|
|
|
/// Sets the clock rate of the delegate.
|
|
void set_clock_rate(double clock_rate);
|
|
|
|
/*!
|
|
If the delegate is not currently in the process of an `update` call, calls it now to catch up to the current time.
|
|
The call is asynchronous; this method will return immediately.
|
|
*/
|
|
void update();
|
|
|
|
/// Blocks until any ongoing update is complete.
|
|
void flush();
|
|
|
|
private:
|
|
std::atomic_flag update_is_ongoing_;
|
|
AsyncTaskQueue async_task_queue_;
|
|
|
|
std::chrono::time_point<std::chrono::high_resolution_clock> previous_time_point_;
|
|
bool has_previous_time_point_ = false;
|
|
double error_ = 0.0;
|
|
bool has_skipped_ = false;
|
|
|
|
Delegate *delegate_ = nullptr;
|
|
double clock_rate_ = 1.0;
|
|
};
|
|
|
|
}
|
|
|
|
#endif /* BestEffortUpdater_hpp */
|