Trait TimeProvider 

pub trait TimeProvider:
    Clone
    + Send
    + Sync
    + 'static {
    // Required methods
    fn sleep(
        &self,
        duration: Duration,
    ) -> impl Future<Output = Result<(), TimeError>> + Send;
    fn now(&self) -> Duration;
    fn timer(&self) -> Duration;
    fn timeout<F, T>(
        &self,
        duration: Duration,
        future: F,
    ) -> impl Future<Output = Result<T, TimeError>> + Send
       where F: Future<Output = T> + Send,
             T: Send;
}

Provider trait for time operations.

This trait allows code to work with both simulation time and real wall-clock time in a unified way. Implementations handle sleeping and getting current time appropriate for their environment.

Time Semantics

• now(): Returns the exact, canonical time. Use this for scheduling and precise comparisons.
• timer(): Returns a potentially drifted time that can be slightly ahead of now(). In simulation, this simulates real-world clock drift. In production, this equals now().

FDB ref: sim2.actor.cpp:1056-1064

Required Methods

fn sleep( &self, duration: Duration, ) -> impl Future<Output = Result<(), TimeError>> + Send

Sleep for the specified duration.

In simulation, this advances simulation time. In real time, this uses actual wall-clock delays.

fn now(&self) -> Duration

Get exact current time.

In simulation, this returns the canonical simulation time. In real time, this returns wall-clock elapsed time since provider creation.

Use this for precise time comparisons and event scheduling.

fn timer(&self) -> Duration

Get drifted timer time.

In simulation, this can be up to clock_drift_max (default 100ms) ahead of now(). This simulates real-world clock drift between processes. In real time, this equals now().

Use this for time-sensitive application logic like timeouts, leases, and heartbeats to test how code handles clock drift.

FDB ref: sim2.actor.cpp:1058-1064

fn timeout<F, T>( &self, duration: Duration, future: F, ) -> impl Future<Output = Result<T, TimeError>> + Send

where F: Future<Output = T> + Send, T: Send,

Run a future with a timeout.

Returns Ok(result) if the future completes within the timeout, or Err(TimeError::Elapsed) if it times out.

Dyn Compatibility

This trait is not dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety".

Implementors

impl TimeProvider for TokioTimeProvider

Available on crate feature tokio-providers only.