snapshot

Returns a point-in-time snapshot of the circuit breaker state.

Thread-safety note: The three fields (CircuitBreakerSnapshot.state, CircuitBreakerSnapshot.failureCount, CircuitBreakerSnapshot.successCount) are read from @Volatile fields without holding the internal Mutex. Each field is individually visible across threads, but the combination may be momentarily inconsistent (e.g. state could reflect CLOSED while failureCount has already been reset by a transition to OPEN). This is an intentional trade-off: the snapshot is an approximation suitable for health-check endpoints and dashboards, not for strict invariant enforcement. The cost of a mutex-protected read for every health probe would outweigh the benefit given the short window of inconsistency.