Struct XArray

pub struct XArray<T: ForeignOwnable> { /* private fields */ }

An array which efficiently maps sparse integer indices to owned objects.

This is similar to a crate::alloc::kvec::Vec<Option<T>>, but more efficient when there are holes in the index space, and can be efficiently grown.

Invariants

self.xa is always an initialized and valid [bindings::xarray] whose entries are either XA_ZERO_ENTRY or came from T::into_foreign.

Examples

use kernel::alloc::KBox;
use kernel::xarray::{AllocKind, XArray};

let xa = KBox::pin_init(XArray::new(AllocKind::Alloc1), GFP_KERNEL)?;

let dead = KBox::new(0xdead, GFP_KERNEL)?;
let beef = KBox::new(0xbeef, GFP_KERNEL)?;

let mut guard = xa.lock();

assert_eq!(guard.get(0), None);

assert_eq!(guard.store(0, dead, GFP_KERNEL)?.as_deref(), None);
assert_eq!(guard.get(0).copied(), Some(0xdead));

*guard.get_mut(0).unwrap() = 0xffff;
assert_eq!(guard.get(0).copied(), Some(0xffff));

assert_eq!(guard.store(0, beef, GFP_KERNEL)?.as_deref().copied(), Some(0xffff));
assert_eq!(guard.get(0).copied(), Some(0xbeef));

guard.remove(0);
assert_eq!(guard.get(0), None);

Implementations

impl<T: ForeignOwnable> XArray<T>

pub fn new(kind: AllocKind) -> impl PinInit<Self>

Creates a new initializer for this type.

pub fn try_lock(&self) -> Option<Guard<'_, T>>

Attempts to lock the XArray for exclusive access.

pub fn lock(&self) -> Guard<'_, T>

Locks the XArray for exclusive access.

Trait Implementations

impl<T: ForeignOwnable> Drop for XArray<T>

fn drop(&mut self)

Executes the destructor for this type.

impl<T: ForeignOwnable> HasPinData for XArray<T>

type PinData = __ThePinData<T>

unsafe fn __pin_data() -> Self::PinData

impl<T: ForeignOwnable> PinnedDrop for XArray<T>

fn drop(self: Pin<&mut Self>, _: OnlyCallFromDrop)

Executes the pinned destructor of this type.

impl<T: ForeignOwnable + Send> Send for XArray<T>

impl<T: ForeignOwnable + Send> Sync for XArray<T>