threaded_estop_reader.h

#pragma once
 
#pragma once
 
 
#include <boost/asio.hpp>
#include <iostream>
#include <mutex>
#include <thread>
 
#include "shared/constants.h"
#include "software/uart/uart_communication.h"
#include "software/util/make_enum/make_enum.hpp"
 
// enum that represents the possible states of estop
MAKE_ENUM(EstopState, PLAY, STOP, STATUS_ERROR);
 
/*
 * class that reads status of estop at periodic intervals of time
 */
class ThreadedEstopReader
{
   public:
    ThreadedEstopReader(std::unique_ptr<UartCommunication> uart_reader);
    ~ThreadedEstopReader();
 
    bool isEstopPlay();
 
 
   private:
    /*
     * handler method that is called every time the timer expires and a new read is
     * requested
     */
    void tick(const boost::system::error_code&);
 
    /*
     * method that initiates timer
     */
    void continousRead();
 
    // In the case where we read an unknown message (not PLAY or STOP) we try again this
    // number of times
    static constexpr unsigned int MAXIMUM_CONSECUTIVE_STATUS_ERROR = 5;
 
    // time between consecutive reads
    static constexpr int INTERVAL_BETWEEN_READS_MS = 5;
 
    // thread that will periodically pull values from the buffer
    std::thread estop_thread;
    std::atomic_bool in_destructor = false;
 
    // current state of estop
    std::atomic<EstopState> estop_state;
 
    // tracks the number of unknown messages received in a row
    unsigned int num_consecutive_status_error = 0;
 
    // Time between reads
    unsigned int regular_read_interval_ms;
 
 
    // boost construct for managing io operations
    boost::asio::io_service io_service;
 
    // timer that expires after every specified interval of time
    boost::asio::deadline_timer timer;
 
    // the UART device acting as source of estop values
    std::unique_ptr<UartCommunication> uart_reader;
};