Function madvise::madvise

pub unsafe fn madvise(
    ptr: *const u8, 
    len: usize, 
    advice: AccessPattern
) -> Result<()>

Raw advise wrapper with proper error handling. This enforces the same contract as libc::madvise. Specifically, ptr must be non-null and the data between ptr and ptr + len must be initialized.

Example

use madvise::{AccessPattern, madvise};
use std::mem;

struct BigStruct([u8; 1024]);

let mut heap_allocated_big_struct = Box::new(BigStruct([0; 1024]));
unsafe {
    madvise(
        Box::as_ref(&heap_allocated_big_struct) as *const BigStruct as *const u8,
        mem::size_of::<BigStruct>(),
        AccessPattern::Sequential
    ).expect("Advisory failed");
}

for i in heap_allocated_big_struct.0.iter_mut() {
    *i += 1
}