Struct slabmalloc::ObjectPage8k

#[repr(C)]
pub struct ObjectPage8k<'a> {
    pub mp: Option<MappedPages8k>,
    pub heap_id: usize,
    /* private fields */
}

Holds allocated data within 2 4-KiB pages.

Has a data-section where objects are allocated from and a small amount of meta-data in form of a bitmap to track allocations at the end of the page.

Notes

An object of this type will be exactly 8 KiB. It is marked repr(C) because we rely on a well defined order of struct members (e.g., dealloc does a cast to find the bitfield).

Fields

mp: Option<MappedPages8k>

The MappedPages this memory area belongs to

heap_id: usize

Trait Implementations

impl<'a> AllocablePage for ObjectPage8k<'a>

fn new(mp: MappedPages8k, heap_id: usize) -> ObjectPage8k<'a>

Creates a new 8KiB allocable page and stores the MappedPages object in the metadata portion.

fn retrieve_mapped_pages(&mut self) -> Option<MappedPages8k>

Returns the MappedPages object that was stored in the metadata portion of the page.

fn clear_metadata(&mut self)

clears the metadata section of the page

const SIZE: usize = 8_192usize

The total size (in bytes) of the page.

const METADATA_SIZE: usize = 128usize

const HEAP_ID_OFFSET: usize = 8_104usize

fn set_heap_id(&mut self, heap_id: usize)

fn heap_id(&self) -> usize

fn bitfield(&self) -> &[AtomicU64; 8]

fn bitfield_mut(&mut self) -> &mut [AtomicU64; 8]

fn prev(&mut self) -> &mut Rawlink<Self>

fn next(&mut self) -> &mut Rawlink<Self>

fn buffer_size() -> usize

fn first_fit(&self, layout: Layout) -> Option<(usize, usize)>

Tries to find a free block within data that satisfies alignment requirement.

fn allocate(&mut self, layout: Layout) -> *mut u8

Tries to allocate an object within this page.

fn is_full(&self) -> bool

Checks if we can still allocate more objects of a given layout within the page.

fn is_empty(&self, relevant_bits: usize) -> bool

Checks if the page has currently no allocations.

fn deallocate( &self, ptr: NonNull<u8>, layout: Layout ) -> Result<(), &'static str>

Deallocates a memory object within this page.

impl<'a> Debug for ObjectPage8k<'a>

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl<'a> Default for ObjectPage8k<'a>

fn default() -> ObjectPage8k<'a>

Returns the “default value” for a type.

impl<'a> Send for ObjectPage8k<'a>

impl<'a> Sync for ObjectPage8k<'a>