vendor/rustix/src/mm/madvise.rs

   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")]
  33 pub unsafe fn madvise(addr: *mut c_void, len: usize, advice: Advice) -> io::Result<()> {
  34     backend::mm::syscalls::madvise(addr, len, advice)
  35 }