当epoll_wait返回EPOLLERR时，如何获取errno? [英] How to get errno when epoll_wait returns EPOLLERR?

问题描述

当epoll_wait针对特定fd返回EPOLLERR时，是否可以找到errno?

Is there a way to find out the errno when epoll_wait returns EPOLLERR for a particular fd?

是否有关于错误性质的更多信息?

Is there any further information about the nature of the error?

添加更多信息以防止歧义

Adding more information to prevent ambiguity

epoll_wait等待许多文件描述符.调用epoll_wait时，将其传递给epoll_event结构数组:

epoll_wait waits on a number of file descriptors. When you call epoll_wait you pass it an array of epoll_event structures:

struct epoll_event {
           uint32_t     events;    /* Epoll events */
           epoll_data_t data;      /* User data variable */
       };

epoll_data_t结构的详细信息与您使用epoll_ctl向epoll添加文件描述符的结构相同:

The epoll_data_t structure has the same details as the one you used with epoll_ctl to add a file descriptor to epoll:

typedef union epoll_data {
           void    *ptr;
           int      fd;
           uint32_t u32;
           uint64_t u64;
       } epoll_data_t;

我正在寻找的是当epoll等待的文件描述符之一出现错误时会发生什么情况.

What I'm looking for is what happens when there is an error on one of the file descriptors that epoll is waiting on.

ie:(epoll_event.events & EPOLLERR) == 1-有没有办法在文件描述符上找出错误的更多详细信息?

ie: (epoll_event.events & EPOLLERR) == 1 - is there a way to find out more details of the error on the file descriptor?

推荐答案

使用getsockopt和SO_ERROR在套接字上获取挂起的错误

Use getsockopt and SO_ERROR to get the pending error on the socket

int       error = 0;
socklen_t errlen = sizeof(error);
if (getsockopt(fd, SOL_SOCKET, SO_ERROR, (void *)&error, &errlen) == 0)
{
    printf("error = %s\n", strerror(error));
}

这篇关于当epoll_wait返回EPOLLERR时，如何获取errno?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！