Struct CpuTopology

pub struct CpuTopology {
    pub logical_cpus: Option<usize>,
    pub caches: Vec<CacheLevel>,
    pub heterogeneous_cores: Option<bool>,
}

The measured shape of the host machine.

Every field is optional because an unmeasured value must stay visibly absent rather than silently defaulted.

Fields

logical_cpus: Option<usize>

Logical CPUs usable by this process, honouring CPU affinity.

caches: Vec<CacheLevel>

Data and unified cache levels, ascending by level.

heterogeneous_cores: Option<bool>

Whether cores have differing capability (P/E cores, Snapdragon X).

None means undetermined, which is not the same as Some(false). Even work splitting is wrong on a heterogeneous machine, so the distinction matters.

Implementations

impl CpuTopology

pub fn detect() -> CpuTopology

Detect the host’s shape. Unavailable values stay None.

pub fn cache_bytes(&self, level: u8) -> Option<usize>

Bytes in the given cache level, if measured.

pub fn last_level_bytes(&self) -> Option<usize>

Bytes in the largest measured cache level.

pub fn line_bytes(&self) -> Option<usize>

Cache line size, if measured.

pub fn fits_in_cache(&self, bytes: usize, level: u8) -> Option<bool>

Whether a working set of bytes fits in the given level.

None when the level was not measured – the caller must decide what to do without the number rather than receive a fabricated false.

Trait Implementations

impl Clone for CpuTopology

fn clone(&self) -> CpuTopology

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for CpuTopology

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

Formats the value using the given formatter.

impl Default for CpuTopology

fn default() -> CpuTopology

Returns the “default value” for a type.

impl PartialEq for CpuTopology

fn eq(&self, other: &CpuTopology) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl Eq for CpuTopology

impl StructuralPartialEq for CpuTopology