boost - 串口通信 超时处理

另外一个方法是使用前面说过的异步读写+超时的方式，代码如下：#include <iostream>#include <boost/asio.hpp>#include <boost/bind.hpp>using namespace std;using namespace boost::asio;void handle_read(char *buf,boost::system::error_code ec, std::size_t bytes_transferred){         cout.write(buf, bytes_transferred);}int main(int argc, char* argv[]){         io_service iosev;         serial_port sp(iosev,  "COM1");         sp.set_option(serial_port::baud_rate(19200));         sp.set_option(serial_port::flow_control());         sp.set_option(serial_port::parity());         sp.set_option(serial_port::stop_bits());         sp.set_option(serial_port::character_size(8));         write(sp, buffer("Hello world", 12));         // 异步读         char buf[100];         async_read(sp, buffer(buf), boost::bind(handle_read, buf, _1, _2));         // 100ms后超时         deadline_timer timer(iosev);         timer.expires_from_now(boost::posix_time::millisec(100));         // 超时后调用sp的cancel()方法放弃读取更多字符         timer.async_wait(boost::bind(&serial_port::cancel, boost::ref(sp)));         iosev.run();         return 0;} //

    boost::asio::async_read(m_port, boost::asio::buffer(m_cData), boost::bind(&SerialPort::handle_read, this, boost::asio::placeholders::error, boost::asio::placeholders::bytes_transferred));        boost::asio::deadline_timer timer(m_ios);        timer.expires_from_now(boost::posix_time::millisec(1000*20));        timer.async_wait(boost::bind(&boost::asio::serial_port::cancel, boost::ref(m_port))); //超时后调用cancel()方法放弃读取更多字符//

boost::asio::async_read() cannot be used with null_buffers()

An attempt to use async_read() with null_buffers() causes the handler to be invoked even when the underlying file descriptor is not yet available for reading.