epoll_ctl(epfd, EPOLL_CTL_ADD, m_fd, &ev) get an error

[Hong]

when i call epoll_ctl(epfd, EPOLL_CTL_ADD, m_fd, &ev) while pass same m_fd , it return -1,
I getlasterror, and it is 183
but I run same condition under linux , everything is ok, please help for fix it, thanks

[Ben Noordhuis]

If 183 maps to EEXIST then it looks correct to me, that's what epoll_ctl() returns on Linux when you try to register the same file descriptor twice.

[Hong]

thanks.