__must_check int mark_fd_blocking(int fd);
void para_fd_set(int fd, fd_set *fds, int *max_fileno);
__must_check int para_fgets(char *line, int size, FILE *f);
__must_check int mark_fd_blocking(int fd);
void para_fd_set(int fd, fd_set *fds, int *max_fileno);
__must_check int para_fgets(char *line, int size, FILE *f);