[Boost-bugs] [Boost C++ Libraries] #11721: boost::asio::serial_port bug in win10

Subject: [Boost-bugs] [Boost C++ Libraries] #11721: boost::asio::serial_port bug in win10
From: Boost C++ Libraries (noreply_at_[hidden])
Date: 2015-10-13 07:57:36

#11721: boost::asio::serial_port bug in win10
--------------------------+----------------------------
 Reporter:  admin@…       |      Owner:  chris_kohlhoff
     Type:  Bugs          |     Status:  new
Milestone:  Boost 1.59.0  |  Component:  asio
  Version:  Boost 1.59.0  |   Severity:  Problem
 Keywords:  serial_port   |
--------------------------+----------------------------
 在最近写一些串口操作的程序时使用了 boost::asio::serial_port 来操作串口
 ä½†å½“å°è¯•æ‰“å¼€ä¸²å£çš„æ—¶å€™å‡ºçŽ°äº†é”™è¯¯ã€‚ä¸‹é¢æ˜¯æˆ‘çš„æµ‹è¯•ä»£ç ï¼š
 {{{#!cpp
 boost::asio::io_service _io_service;
 const std::string devname = "COM3";
 try
 {
         boost::asio::serial_port serial(_io_service);
         serial.open(devname);// throw error every times.
         if (serial.is_open()) {
                 std::cout << devname << " serial open successed." <<
 std::endl;
         }
         else {
                 std::cout << devname << " serial open failed!" <<
 std::endl;
         }
 }
 catch (const std::exception& ex)
 {
         std::cout << ex.what() << std::endl;// GetLastError() == 87
 }
 }}}
 每次都会出现错误87。即 GetLastError() 的结果为 87
 äºŽæ˜¯è·Ÿè¿›ä»£ç é‡Œé¢è°ƒè¯•è¿½åˆ°äº† win_iocp_serial_port_service::open 函数里

 win_iocp_serial_port_service::open 函数的实现如下：
 {{{#!cpp
 boost::system::error_code win_iocp_serial_port_service::open(
         win_iocp_serial_port_service::implementation_type& impl,
         const std::string& device, boost::system::error_code& ec)
 {
         if (is_open(impl))
         {
                 ec = boost::asio::error::already_open;
                 return ec;
         }

         std::string name = (device[0] == '\\') ? device : "\\\\.\\" +
 device;

         ::HANDLE handle = ::CreateFileA(name.c_str(),
                 GENERIC_READ | GENERIC_WRITE, 0, 0,
                 OPEN_EXISTING, FILE_FLAG_OVERLAPPED, 0);
         if (handle == INVALID_HANDLE_VALUE)
         {
                 DWORD last_error = ::GetLastError();
                 ec = boost::system::error_code(last_error,
                         boost::asio::error::get_system_category());
                 return ec;
         }

         using namespace std;
         ::DCB dcb;
         memset(&dcb, 0, sizeof(DCB));
         dcb.DCBlength = sizeof(DCB);
         if (!::GetCommState(handle, &dcb))
         {
                 DWORD last_error = ::GetLastError();
                 ::CloseHandle(handle);
                 ec = boost::system::error_code(last_error,
                         boost::asio::error::get_system_category());
                 return ec;
         }

         dcb.fBinary = TRUE;
         dcb.fDsrSensitivity = FALSE;
         dcb.fNull = FALSE;
         dcb.fAbortOnError = FALSE;

         if (!::SetCommState(handle, &dcb))
         {
                 DWORD last_error = ::GetLastError();// lee: error is
 here!!!
                 ::CloseHandle(handle);
                 ec = boost::system::error_code(last_error,
                         boost::asio::error::get_system_category());
                 return ec;
         }

         ::COMMTIMEOUTS timeouts;
         timeouts.ReadIntervalTimeout = 1;
         timeouts.ReadTotalTimeoutMultiplier = 0;
         timeouts.ReadTotalTimeoutConstant = 0;
         timeouts.WriteTotalTimeoutMultiplier = 0;
         timeouts.WriteTotalTimeoutConstant = 0;
         if (!::SetCommTimeouts(handle, &timeouts))
         {
                 DWORD last_error = ::GetLastError();
                 ::CloseHandle(handle);
                 ec = boost::system::error_code(last_error,
                         boost::asio::error::get_system_category());
                 return ec;
         }

         if (handle_service_.assign(impl, handle, ec))
                 ::CloseHandle(handle);
         return ec;
 }
 }}}
 发现每次在第一次 SetCommState 的时候总是会报错并离开。
 于是查看了前面通过 GetCommState 获取到的 dcb 的值。
 发现 dcb.BaudRate == 0 æ—¶æ— æ³• SetCommState 成功
 也就是说在有些设备中获取不到 dcb.BaudRate 这个值。

 == 下面是我自己的解决办法： ==
 在 win_iocp_serial_port_service.ipp 文件的88è¡Œå·¦å³æ·»åŠ 
 {{{#!cpp
 if (dcb.BaudRate == 0) dcb.BaudRate = 115200;
 }}}

 修改后的 win_iocp_serial_port_service::open å‡½æ•°å®Œæ•´ä»£ç å¦‚ä¸‹ï¼š
 {{{#!cpp
 boost::system::error_code win_iocp_serial_port_service::open(
         win_iocp_serial_port_service::implementation_type& impl,
         const std::string& device, boost::system::error_code& ec)
 {
         if (is_open(impl))
         {
                 ec = boost::asio::error::already_open;
                 return ec;
         }

         std::string name = (device[0] == '\\') ? device : "\\\\.\\" +
 device;

         ::HANDLE handle = ::CreateFileA(name.c_str(),
                 GENERIC_READ | GENERIC_WRITE, 0, 0,
                 OPEN_EXISTING, FILE_FLAG_OVERLAPPED, 0);
         if (handle == INVALID_HANDLE_VALUE)
         {
                 DWORD last_error = ::GetLastError();
                 ec = boost::system::error_code(last_error,
                         boost::asio::error::get_system_category());
                 return ec;
         }

         using namespace std;
         ::DCB dcb;
         memset(&dcb, 0, sizeof(DCB));
         dcb.DCBlength = sizeof(DCB);
         if (!::GetCommState(handle, &dcb))
         {
                 DWORD last_error = ::GetLastError();
                 ::CloseHandle(handle);
                 ec = boost::system::error_code(last_error,
                         boost::asio::error::get_system_category());
                 return ec;
         }

         dcb.fBinary = TRUE;
         dcb.fDsrSensitivity = FALSE;
         dcb.fNull = FALSE;
         dcb.fAbortOnError = FALSE;
         if (dcb.BaudRate == 0) dcb.BaudRate = 115200; // add lee
 2015.10.10. 解决dcb.BaudRate为0æ—¶æ— æ³•æˆåŠŸSetCommStateçš„BUG
         if (!::SetCommState(handle, &dcb))
         {
                 DWORD last_error = ::GetLastError();
                 ::CloseHandle(handle);
                 ec = boost::system::error_code(last_error,
                         boost::asio::error::get_system_category());
                 return ec;
         }

         ::COMMTIMEOUTS timeouts;
         timeouts.ReadIntervalTimeout = 1;
         timeouts.ReadTotalTimeoutMultiplier = 0;
         timeouts.ReadTotalTimeoutConstant = 0;
         timeouts.WriteTotalTimeoutMultiplier = 0;
         timeouts.WriteTotalTimeoutConstant = 0;
         if (!::SetCommTimeouts(handle, &timeouts))
         {
                 DWORD last_error = ::GetLastError();
                 ::CloseHandle(handle);
                 ec = boost::system::error_code(last_error,
                         boost::asio::error::get_system_category());
                 return ec;
         }

         if (handle_service_.assign(impl, handle, ec))
                 ::CloseHandle(handle);
         return ec;
 }
 }}}

 == 测试环境 ==
 ||= 说明 =||= 参数 =||
 || 操作系统 || Windows10 专业版 x64 ||
 || 开发环境 || Microsoft Visual Studio Community 2013 Version 12.0.40629.00
 Update 5 ||
 || Boost版本 || boost_1.59.0 ||

 == 结束语 ==
 以上只是自己的猜测，并不一定是完全正确的。如有任何错误，请联系并告诉我。我将尽快修改，不胜感激。

 == 我的原文 ==
 http://www.leelib.com/2015/10/10/win10-boost-asio-serial-port-bug.html

-- 
Ticket URL: <https://svn.boost.org/trac/boost/ticket/11721>
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