c++ - 如何通过 boost::asio 和 shared_ptr 创建串口

Question

起初，我不是 C++ 编程专家，我的问题可能非常初级。

我正在尝试使用 boost asio 访问串行端口并使用 shared_ptr 来防止内存泄漏。我搜索了一些示例代码，但对我来说，其中很多都不起作用。

我的代码如下:

串口连接.cpp:

#include "SerialPortConnection.h"
SerialPortConnection::SerialPortConnection( std::string port_name_init, int baud_rate_init,
        boost::asio::serial_port_base::character_size        charSize_init,
        boost::asio::serial_port_base::stop_bits             stopBit_init,
        boost::asio::serial_port_base::parity                pariy_init,
        boost::asio::serial_port_base::flow_control          flowControl_init)        :
        port_name(port_name_init),
        baud_rate(baud_rate_init),
        charSize(charSize_init),
        stopBit(stopBit_init),
        pariy(pariy_init),
        flowControl(flowControl_init)
{
port = boost::shared_ptr<serial_port_ptr>( new boost::asio::serial_port );
}
SerialPortConnection::~SerialPortConnection()
{
    //dtor
}

串口连接.h:

#ifndef SERIALPORTCONNECTION_H
#define SERIALPORTCONNECTION_H
#include <iostream>
#include <string>
#include <memory>
#include <boost/asio.hpp>
#include <boost/asio/serial_port.hpp>
#include <boost/shared_ptr.hpp>
#include <boost/make_shared.hpp>
//using namespace::boost::asio;
class SerialPortConnection
{
public:
    SerialPortConnection( std::string port_name_init, int baud_rate_init,
                          boost::asio::serial_port_base::character_size        charSize000_init,
                          boost::asio::serial_port_base::stop_bits             stopBit000_init,
                          boost::asio::serial_port_base::parity                pariy000_init,
                          boost::asio::serial_port_base::flow_control          flowControl_init );
    virtual ~SerialPortConnection();
private:
    std::string port_name;
    int baud_rate;
    boost::asio::serial_port_base::character_size        charSize;
    boost::asio::serial_port_base::stop_bits             stopBit;
    boost::asio::serial_port_base::parity                pariy;
    boost::asio::serial_port_base::flow_control          flowControl;
    boost::asio::io_service io;
    typedef boost::asio::serial_port* serial_port_ptr;
    boost::shared_ptr < serial_port_ptr > port;
};
#endif // SERIALPORTCONNECTION_H

编译器产生编译错误:

||=== Build: Debug in test-1 (compiler: GNU GCC Compiler) ===|
/home/mkh/cb-codes/test-prjs/test-1/src/SerialPortConnection.cpp||In constructor ‘SerialPortConnection::SerialPortConnection(std::__cxx11::string, int, boost::asio::serial_port_base::character_size, boost::asio::serial_port_base::stop_bits, boost::asio::serial_port_base::parity, boost::asio::serial_port_base::flow_control)’:|
/home/mkh/cb-codes/test-prjs/test-1/src/SerialPortConnection.cpp|17|error: no matching function for call to ‘boost::asio::basic_serial_port<>::basic_serial_port()’|
/usr/include/boost/asio/basic_serial_port.hpp|147|note: candidate: boost::asio::basic_serial_port<SerialPortService>::basic_serial_port(boost::asio::basic_serial_port<SerialPortService>&&) [with SerialPortService = boost::asio::serial_port_service]|
/usr/include/boost/asio/basic_serial_port.hpp|147|note:   candidate expects 1 argument, 0 provided|
/usr/include/boost/asio/basic_serial_port.hpp|126|note: candidate: boost::asio::basic_serial_port<SerialPortService>::basic_serial_port(boost::asio::io_service&, const native_handle_type&) [with SerialPortService = boost::asio::serial_port_service; boost::asio::basic_serial_port<SerialPortService>::native_handle_type = int]|
/usr/include/boost/asio/basic_serial_port.hpp|126|note:   candidate expects 2 arguments, 0 provided|
/usr/include/boost/asio/basic_serial_port.hpp|105|note: candidate: boost::asio::basic_serial_port<SerialPortService>::basic_serial_port(boost::asio::io_service&, const string&) [with SerialPortService = boost::asio::serial_port_service; std::__cxx11::string = std::__cxx11::basic_string<char>]|
/usr/include/boost/asio/basic_serial_port.hpp|105|note:   candidate expects 2 arguments, 0 provided|
/usr/include/boost/asio/basic_serial_port.hpp|85|note: candidate: boost::asio::basic_serial_port<SerialPortService>::basic_serial_port(boost::asio::io_service&, const char*) [with SerialPortService = boost::asio::serial_port_service]|
/usr/include/boost/asio/basic_serial_port.hpp|85|note:   candidate expects 2 arguments, 0 provided|
/usr/include/boost/asio/basic_serial_port.hpp|69|note: candidate: boost::asio::basic_serial_port<SerialPortService>::basic_serial_port(boost::asio::io_service&) [with SerialPortService = boost::asio::serial_port_service]|
/usr/include/boost/asio/basic_serial_port.hpp|69|note:   candidate expects 1 argument, 0 provided|
||=== Build failed: 1 error(s), 0 warning(s) (0 minute(s), 1 second(s)) ===|

我尝试过各种解决方案。例如，我将这个添加到 SerialPortConnection.h:

boost::asio::serial_port port0;

但它也不起作用。它实际上会导致另一个编译错误。 现在我需要知道如何使用 shared_ptr 创建串行端口。

谢谢，

Answer 1

shared_ptr 是不必要的。这是一个代码片段:

#include <boost/asio/serial_port.hpp>

class SerialPortConnection
{
public:
   SerialPortConnection();

private:
   boost::asio::io_service    m_ioService;  //order is important so that m_ioService gets constructed first
   boost::asio::serial_port   m_port;
};

SerialPortConnection::SerialPortConnection()
: m_port(m_ioService)
{
   boost::system::error_code ec;  // choice: without ec Boost.Asio may throw

   m_port.open("COM1", ec);

   if (!ec)
   {
       boost::asio::serial_port_base::baud_rate baud_rate1(9600);   
       m_port.set_option(baud_rate1);

      //etc.
   }
}

请注意，Boost.Asio 主要使用异步模型。它也支持同步操作，但不支持超时(这是一个主要用例)并且模仿该行为很麻烦。