错误序列的libserial接收数据 [英] wrong sequence of libserial received data

问题描述

我现在正在使用libserial在Ubuntu下进行串口通信的项目。我们修改了libserial源代码以允许MARK / SPACE奇偶校验。但是当进行数据接收测试时，有时（约5％的机会）输入数据序列是错误的。第一个字节可以跳转到传入缓冲区的中间或甚至结束。

I'm now working on a project which uses libserial for serial port communication under Ubuntu. we modified the libserial source code to allow MARK/SPACE parity. but when doing data receiving test, sometimes (about 5% chance) the incoming data sequence is wrong. The first byte can jump to the middle of the incoming buffer or even to the end.

问题在于原来的 SerialPort :: SerialPortImpl： ：HandlePosixSignal（int singnalNumber）f unction，当错误发生时，它不能正确读取一些字节，错误描述是资源暂时不可用。但是，由于它已经使用ioctl获得 num_of_bytes_available ，在测试期间可能会失败？

The problem is inside the original SerialPort::SerialPortImpl::HandlePosixSignal( int singnalNumber) function, when the error happens it can not read some byte correctly and the error description is "Resource temporarily unavailable". But since it already get num_of_bytes_available using ioctl, how is it possible to fail?

之间的MARK / SPACE奇偶校验。是否会导致问题？

during my test, I toggle between MARK/SPACE parity frequently. will that cause the problem?

SetParity 函数中的修改部分

for **PARITY_SPACE**

port_settings.c_cflag |= CMSPAR | PARENB;

port_settings.c_cflag &= ~PARODD;

port_settings.c_iflag = 0;

for **PARITY_MARK**

port_settings.c_cflag |= CMSPAR | PARENB;

port_settings.c_iflag = 0;

推荐答案

好的，我终于知道是什么原因。 libserial SerialPort 类不是线程安全的。 POSIX信号可能与升压线程冲突。我能够通过切换到 SerialStream 类来解决这个问题。

Okay, I finally figured out what was causing the problem. The libserial SerialPort class is not thread-safe. A POSIX signal probably conflicted with the boost thread. I was able to solve the problem by switching to the SerialStream class.

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