Struct PerCpuArray 

pub struct PerCpuArray<T, V: Pod> { /* private fields */ }

A per-CPU fixed-size array.

The size of the array is defined on the eBPF side using the bpf_map_def::max_entries field. All the entries are zero-initialized when the map is created.

Minimum kernel version

The minimum kernel version required to use this feature is 4.6.

Examples

use aya::maps::{PerCpuArray, PerCpuValues};
use aya::util::nr_cpus;

let mut array = PerCpuArray::try_from(bpf.map_mut("ARRAY").unwrap())?;

// set array[1] = 42 for all cpus
let nr_cpus = nr_cpus().map_err(|(_, error)| error)?;
array.set(1, PerCpuValues::try_from(vec![42u32; nr_cpus])?, 0)?;

// retrieve the values at index 1 for all cpus
let values = array.get(&1, 0)?;
assert_eq!(values.len(), nr_cpus);
for cpu_val in values.iter() {
    assert_eq!(*cpu_val, 42u32);
}

Implementations

impl<T: Borrow<MapData>, V: Pod> PerCpuArray<T, V>

pub fn len(&self) -> u32

Returns the number of elements in the array.

This corresponds to the value of bpf_map_def::max_entries on the eBPF side.

pub fn get(&self, index: &u32, flags: u64) -> Result<PerCpuValues<V>, MapError>

Returns a slice of values - one for each CPU - stored at the given index.

Errors

Returns MapError::OutOfBounds if index is out of bounds, MapError::SyscallError if bpf_map_lookup_elem fails.

pub fn iter( &self, ) -> impl Iterator<Item = Result<PerCpuValues<V>, MapError>> + '_

An iterator over the elements of the array. The iterator item type is Result<PerCpuValues<V>, MapError>.

impl<T: BorrowMut<MapData>, V: Pod> PerCpuArray<T, V>

pub fn set( &mut self, index: u32, values: PerCpuValues<V>, flags: u64, ) -> Result<(), MapError>

Sets the values - one for each CPU - at the given index.

Errors

Returns MapError::OutOfBounds if index is out of bounds, MapError::SyscallError if bpf_map_update_elem fails.

impl<T: Borrow<MapData>, V: Pod> PerCpuArray<T, V>

pub fn pin<P: AsRef<Path>>(self, path: P) -> Result<(), PinError>

Pins the map to a BPF filesystem.

When a map is pinned it will remain loaded until the corresponding file is deleted. All parent directories in the given path must already exist.

impl<V: Pod> PerCpuArray<MapData, V>

pub fn create(max_entries: u32, flags: u32) -> Result<Self, MapError>

Creates a standalone map with the given max_entries capacity and flags.

Trait Implementations

impl<T: Borrow<MapData>, V: Pod> IterableMap<u32, PerCpuValues<V>> for PerCpuArray<T, V>

fn map(&self) -> &MapData

Get a generic map handle

fn get(&self, key: &u32) -> Result<PerCpuValues<V>, MapError>

Get the value for the provided key

impl<'a, V: Pod> TryFrom<&'a Map> for PerCpuArray<&'a MapData, V>

type Error = MapError

The type returned in the event of a conversion error.

fn try_from(map: &'a Map) -> Result<Self, Self::Error>

Performs the conversion.

impl<'a, V: Pod> TryFrom<&'a mut Map> for PerCpuArray<&'a mut MapData, V>

type Error = MapError

The type returned in the event of a conversion error.

fn try_from(map: &'a mut Map) -> Result<Self, Self::Error>

Performs the conversion.

impl<V: Pod> TryFrom<Map> for PerCpuArray<MapData, V>

type Error = MapError

The type returned in the event of a conversion error.

fn try_from(map: Map) -> Result<Self, Self::Error>

Performs the conversion.