__must_check int mark_fd_blocking(int fd);
int para_mmap(size_t length, int prot, int flags, int fd, void *map);
int para_open(const char *path, int flags, mode_t mode);
__must_check int mark_fd_blocking(int fd);
int para_mmap(size_t length, int prot, int flags, int fd, void *map);
int para_open(const char *path, int flags, mode_t mode);