Struct Clock 

pub struct Clock { /* private fields */ }

Deterministic, in-process clock for chaos testing.

Clock does not advance automatically. Callers explicitly move the clock forward via advance and skew it via skew_by. This makes time-sensitive tests fully reproducible.

Clock is Clone-able and shares state with its clones via an internal Arc<AtomicI64> of nanoseconds-since-anchor; advancing or skewing one handle advances all. Safe to share across threads.

Example

use dev_chaos::clock::Clock;
use std::time::Duration;

let c = Clock::new();
let t0 = c.now();
c.advance(Duration::from_secs(5));
let t1 = c.now();
assert_eq!(t1.since_anchor() - t0.since_anchor(), Duration::from_secs(5));

// Skew negative to simulate clock going backward (e.g. NTP step).
c.skew_by(-(Duration::from_secs(2).as_nanos() as i64));
let t2 = c.now();
assert!(t2 < t1);

Implementations

impl Clock

pub fn new() -> Self

Build a new clock anchored at the current Instant.

pub fn anchor(&self) -> Instant

The real Instant this clock was anchored at.

Callers that need to interoperate with code expecting Instant can compute clock.anchor() + clock.now().since_anchor().

pub fn now(&self) -> ClockTime

Current virtual time, as offset from the anchor.

pub fn now_signed_ns(&self) -> i64

Current virtual offset, signed (in nanoseconds from anchor).

Useful when validating skew-backward scenarios where since_anchor() would clamp.

pub fn advance(&self, delta: Duration)

Advance the clock by a non-negative delta.

Equivalent to skew_by(delta.as_nanos() as i64) but rejects negative durations at the type level.

pub fn skew_by(&self, delta_ns: i64)

Skew the clock by delta_ns, which may be negative.

Negative skew simulates clock-step events (e.g. NTP correction, VM pause/resume backward jump). Tests can validate that retry loops with timeout-based escape don’t get stuck on negative elapsed values.

pub fn reset(&self)

Reset the clock to anchor (offset zero).

Trait Implementations

impl Clone for Clock

fn clone(&self) -> Clock

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Clock

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

Formats the value using the given formatter.

impl Default for Clock

fn default() -> Self

Returns the “default value” for a type.