Struct CircuitBreaker 

pub struct CircuitBreaker { /* private fields */ }

Implementations

impl CircuitBreaker

pub fn new(failure_threshold: u32, cooldown: Duration) -> Self

Runtime constructor.

pub const fn const_new(failure_threshold: u32, cooldown_millis: u64) -> Self

const-friendly constructor used by the #[circuit_breaker] macro.

pub const fn const_named( name: &'static str, failure_threshold: u32, cooldown_millis: u64, ) -> Self

Named variant — the name labels circuit_breaker_transitions_total and the state-change logs.

pub fn state(&self) -> u8

pub async fn execute<F, Fut, T, E>( &self, action: F, ) -> Result<Result<T, E>, BreakerOpen>

where F: FnMut() -> Fut, Fut: Future<Output = Result<T, E>>,

Execute action under breaker supervision.

State machine (all transitions are single CAS operations — no locks):

• CLOSED: calls flow; failure_threshold consecutive-window failures trip to OPEN (cooldown timestamp recorded).
• OPEN: rejected with BreakerOpen until the cooldown elapses; then exactly one caller (the OPEN→HALF_OPEN CAS winner) proceeds as the probe. Everyone else keeps getting BreakerOpen — a recovering dependency is never thundering-herded.
• HALF_OPEN: the probe’s outcome decides — success closes the breaker (counters reset), failure re-opens it with a fresh cooldown.