Struct pmc::Counter

pub struct Counter { /* fields omitted */ }

An allocated PMC counter.

Counters are initialised using the CounterBuilder type.

use std::{thread, time::Duration};

let instr = CounterConfig::default()
    .attach_to(vec![0])
    .allocate("inst_retired.any")?;

let handle = instr.start()?;

// Stop the counter after 5 seconds
thread::sleep(Duration::from_secs(5));
handle.stop();

println!("instructions: {}", instr.read()?);

Implementations

impl Counter

pub fn start(&mut self) -> Result<Running<'_>, Error>

Start this counter.

The counter stops when the returned Running handle is dropped.

pub fn read(&self) -> Result<u64, Error>

Read the counter value.

This call is valid for both running, stopped, and unused counters.

let mut counter = CounterConfig::default()
    .attach_to(vec![0])
    .allocate("inst_retired.any")?;

let r1 = counter.read()?;
let r2 = counter.read()?;

// A counter that is not running does not advance
assert!(r2 == r1);

pub fn set(&mut self, value: u64) -> Result<u64, Error>

Set an explicit counter value.

let mut counter = CounterConfig::default()
    .attach_to(vec![0])
    .allocate("inst_retired.any")?;

let r1 = counter.set(42)?;
// The previous value is returned when setting a new value
assert_eq!(r1, 0);

// Reading the counter returns the value set
let r2 = counter.read()?;
assert_eq!(r2, 42);

Trait Implementations

impl Debug for Counter

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

Formats the value using the given formatter.

impl Display for Counter

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

Formats the value using the given formatter.

impl Drop for Counter

fn drop(&mut self)

Executes the destructor for this type.