boost - 串口通信

備忘使用。

#include <boost/bind.hpp>
#include <boost/asio.hpp>
#include <boost/thread.hpp>
using boost::asio::io_service;
using boost::system::error_code;
using boost::asio::serial_port;
using boost::asio::deadline_timer;
using boost::asio::buffer;

class MyCom
{
public:
    MyCom(void)
    {
        _pSerialPort= new serial_port(_ios);
        _pTimer = new deadline_timer(_ios);
    }
    ~MyCom(void)
    {
        if (_pTimer != NULL)
        {
            delete _pTimer;
            _pTimer = NULL;
        }
        if (_pSerialPort != NULL)
        {
            delete _pSerialPort;
            _pSerialPort = NULL;
        }
    }
    void Open(const string& comName);
    {
        _pSerialPort->open(comName);
        _pSerialPort->set_option(serial_port::flow_control(serial_port::flow_control::none));   //流量控制爲none
        _pSerialPort->set_option(serial_port::parity(serial_port::parity::none));   //奇偶檢驗爲none
        _pSerialPort->set_option(serial_port::stop_bits(serial_port::stop_bits::one));  //停止位爲1
        _pSerialPort->set_option(serial_port::character_size(8));   //字符大小（數據位）爲8
        _pSerialPort->set_option(serial_port::baud_rate(115200));//波特率
    }
    void Send(const string& data)
    {//同步發數據
        _mutex.lock();
        _pSerialPort->write_some(buffer(data, data.size()));
        _mutex.unlock();
    }
    string Recv()
    {//異步收數據
        _mutex.lock();
        memset(_buf, 0, sizeof(_buf));
        _pSerialPort->async_read_some(buffer(_buf, 256),
            boost::bind(&MyCom::RecvHandle, this,
            boost::asio::placeholders::error,//傳送錯誤碼
            boost::asio::placeholders::bytes_transferred//傳送字節數
            ));
        _mutex.unlock();
        _pTimer->expires_from_now(boost::posix_time::millisec(SLEEP_TIME));
        _pTimer->async_wait(boost::bind(&serial_port::cancel, _pSerialPort));
        _ios.run();//異步情況下使用詞句纔開始執行
        _ios.reset();//還原狀態
        return string(_buf, _ret);
    }
    void Close()
    {
        _mutex.lock();
        if (_pSerialPort->is_open())
            _pSerialPort->close();
        _mutex.unlock();
    }

protected:
    void RecvHandle(const error_code& error, size_t bytes_transferred)
    {
        if (!error)
            _pTimer->cancel();//沒有錯誤就結束定時器
        _ret = bytes_transferred;
    }

private:
    boost::asio::io_service _ios;
    serial_port* _pSerialPort;
    deadline_timer* _pTimer;
    char _buf[256];
    size_t _ret;
    boost::mutex _mutex;
};