Struct OwnedMmap

pub struct OwnedMmap(pub *mut c_void, pub usize);

A safe wrapper for a memory-mapped region.

This struct owns the memory-mapped pointer and ensures that munmap is called when it goes out of scope, preventing memory leaks.

Tuple Fields

0: *mut c_void

A raw pointer to the beginning of the memory-mapped area.

1: usize

The total size of the memory-mapped area in bytes.

Implementations

impl OwnedMmap

pub fn new(ptr: *mut c_void, size: usize) -> Self

Constructs a new OwnedMmap from a raw pointer and size.

This is a low-level constructor. Prefer mmap for new allocations.

pub fn mmap(size: usize, huge_page: Option<bool>) -> Result<Self, Error>

Creates a new memory-mapped region.

This function allocates a new anonymous, private memory-mapped region suitable for use as a UMEM. It can optionally be backed by huge pages.

How it works

It first determines whether to use huge pages. If huge_page is None, it checks /proc/meminfo for available huge pages. It then calculates the required size aligned to the page size (standard or huge) and calls libc::mmap with the appropriate flags (MAP_HUGETLB if using huge pages). On success, it returns an OwnedMmap that manages the allocated memory.

pub fn as_void_ptr(&self) -> *mut c_void

Returns the raw pointer to the memory-mapped region.

pub fn as_u8_ptr(&mut self) -> *mut u8

Returns a mutable raw pointer to the memory-mapped region as a byte slice.

pub fn len(&self) -> usize

Returns the size of the memory-mapped region in bytes.

pub fn is_empty(&self) -> bool

Returns true if the memory-mapped region has a size of zero.

Trait Implementations

impl Drop for OwnedMmap

fn drop(&mut self)

Executes the destructor for this type.