timer.hpp

// Copyright 2020 Pokitec
// All rights reserved.
 
 
#pragma once
 
#include "hires_utc_clock.hpp"
#include <mutex>
#include <vector>
#include <functional>
#include <tuple>
#include <thread>
 
namespace tt {
 
class timer {
public:
    using duration = hires_utc_clock::duration;
    using time_point = hires_utc_clock::time_point;
 
    using callback_type = std::function<void(time_point,bool)>;
 
private:
    struct callback_entry {
        size_t id;
        duration interval;
        time_point next_wakeup;
        callback_type callback;
 
        callback_entry(size_t id, duration interval, time_point next_wakeup, callback_type callback) noexcept :
            id(id), interval(interval), next_wakeup(next_wakeup), callback(std::move(callback)) {}
    };
 
    std::string name;
 
    mutable std::mutex mutex;
    std::thread thread;
    std::vector<callback_entry> callback_list;
    size_t callback_count = 0;
 
    bool stop_thread;
 
    [[nodiscard]] std::pair<std::vector<callback_type>,timer::time_point> find_triggered_callbacks(
        timer::time_point current_time
    ) noexcept;
 
    void loop() noexcept;
 
    void start_with_lock_held() noexcept;
 
    void stop_with_lock_held() noexcept;
 
public:
    timer(std::string name) noexcept;
    ~timer();
 
    void start() noexcept;
 
    void stop() noexcept;
 
    [[nodiscard]] size_t add_callback(duration interval, callback_type callback) noexcept;
 
    void remove_callback(size_t callback_id) noexcept;
 
};
 
inline timer maintenance_timer = {"MaintenanceThread"};
 
}