Struct TwoLevelStateStorage

pub struct TwoLevelStateStorage {
    slabs: Vec<OnceOptionBox<[Atomic<MapState>; 8192]>>,
}

A two-level implementation of MapStateStorage.

It is essentially a lazily initialized array of [Atomic<MapState>]. Because it is designed to govern a large address range, and the array is sparse, we use a two-level design. The higher level holds a vector of slabs, and each slab holds an array of [Atomic<MapState>]. Each slab governs an aligned region of MMAP_CHUNKS_PER_SLAB chunks. Slabs are lazily created when the user intends to write into one of its MapState.

Fields

slabs: Vec<OnceOptionBox<[Atomic<MapState>; 8192]>>

Slabs

Implementations

impl TwoLevelStateStorage

pub fn new() -> Self

fn new_slab() -> [Atomic<MapState>; 8192]

fn slab_table(&self, addr: Address) -> Option<&[Atomic<MapState>; 8192]>

fn get_or_allocate_slab_table(&self, addr: Address) -> &[Atomic<MapState>; 8192]

fn slab_index(addr: Address) -> usize

fn in_slab_index(addr: Address) -> usize

fn foreach_slab_slice_for_write<'s, F>(&'s self, range: ChunkRange, f: F)

where F: FnMut(&'s [Atomic<MapState>]),

Visit all slabs that overlap with the range from low to high address. For each slab, call f with the slice of the slab that overlap with the chunks within the range.

Trait Implementations

impl Debug for TwoLevelStateStorage

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

Formats the value using the given formatter.

impl Default for TwoLevelStateStorage

fn default() -> Self

Returns the “default value” for a type.

impl MapStateStorage for TwoLevelStateStorage

fn log_mappable_bytes(&self) -> u8

The logarithm of the address space size this MapStateStorage can handle.

fn get_state(&self, chunk: Address) -> MapState

Return the state of a given chunk (must be aligned).

fn bulk_set_state(&self, range: ChunkRange, state: MapState)

Set all chunks within range to state.

fn bulk_transition_state<F>( &self, range: ChunkRange, update_fn: F, ) -> Result<()>

where F: FnMut(ChunkRange, MapState) -> Result<Option<MapState>>,

Visit the chunk states within range and allow the update_fn callback to inspect and change the states.

impl Send for TwoLevelStateStorage

impl Sync for TwoLevelStateStorage