1 //! The `madvise` function. 2 //! 3 //! # Safety 4 //! 5 //! `madvise` operates on a raw pointer. Some forms of `madvise` may 6 //! mutate the memory or have other side effects. 7 #![allow(unsafe_code)] 8 9 use crate::{backend, io}; 10 use core::ffi::c_void; 11 12 pub use backend::mm::types::Advice; 13 14 /// `posix_madvise(addr, len, advice)`—Declares an expected access pattern 15 /// for a memory-mapped file. 16 /// 17 /// # Safety 18 /// 19 /// `addr` must be a valid pointer to memory that is appropriate to 20 /// call `posix_madvise` on. Some forms of `advice` may mutate the memory 21 /// or evoke a variety of side-effects on the mapping and/or the file. 22 /// 23 /// # References 24 /// - [POSIX] 25 /// - [Linux `madvise`] 26 /// - [Linux `posix_madvise`] 27 /// 28 /// [POSIX]: https://pubs.opengroup.org/onlinepubs/9699919799/functions/posix_madvise.html 29 /// [Linux `madvise`]: https://man7.org/linux/man-pages/man2/madvise.2.html 30 /// [Linux `posix_madvise`]: https://man7.org/linux/man-pages/man3/posix_madvise.3.html 31 #[inline] 32 #[doc(alias = "posix_madvise")] madvise(addr: *mut c_void, len: usize, advice: Advice) -> io::Result<()>33pub unsafe fn madvise(addr: *mut c_void, len: usize, advice: Advice) -> io::Result<()> { 34 backend::mm::syscalls::madvise(addr, len, advice) 35 } 36