Struct tokio::time::Instant

pub struct Instant { /* fields omitted */ }

A measurement of the system clock, useful for talking to external entities like the file system or other processes.

Implementations

impl Instant

pub fn now() -> Instant

Returns an instant corresponding to “now”.

Examples

use tokio::time::Instant;

let now = Instant::now();

pub fn from_std(std: Instant) -> Instant

Create a tokio::time::Instant from a std::time::Instant.

pub fn into_std(self) -> Instant

Convert the value into a std::time::Instant.

pub fn duration_since(&self, earlier: Instant) -> Duration

Returns the amount of time elapsed from another instant to this one.

Panics

This function will panic if earlier is later than self.

pub fn checked_duration_since(&self, earlier: Instant) -> Option<Duration>

Returns the amount of time elapsed from another instant to this one, or None if that instant is later than this one.

Examples

use tokio::time::{Duration, Instant, delay_for};

#[tokio::main]
async fn main() {
    let now = Instant::now();
    delay_for(Duration::new(1, 0)).await;
    let new_now = Instant::now();
    println!("{:?}", new_now.checked_duration_since(now));
    println!("{:?}", now.checked_duration_since(new_now)); // None
}

pub fn saturating_duration_since(&self, earlier: Instant) -> Duration

Returns the amount of time elapsed from another instant to this one, or zero duration if that instant is earlier than this one.

Examples

use tokio::time::{Duration, Instant, delay_for};

#[tokio::main]
async fn main() {
    let now = Instant::now();
    delay_for(Duration::new(1, 0)).await;
    let new_now = Instant::now();
    println!("{:?}", new_now.saturating_duration_since(now));
    println!("{:?}", now.saturating_duration_since(new_now)); // 0ns
}

pub fn elapsed(&self) -> Duration

Returns the amount of time elapsed since this instant was created.

Panics

This function may panic if the current time is earlier than this instant, which is something that can happen if an Instant is produced synthetically.

Examples

use tokio::time::{Duration, Instant, delay_for};

#[tokio::main]
async fn main() {
    let instant = Instant::now();
    let three_secs = Duration::from_secs(3);
    delay_for(three_secs).await;
    assert!(instant.elapsed() >= three_secs);
}

pub fn checked_add(&self, duration: Duration) -> Option<Instant>

Returns Some(t) where t is the time self + duration if t can be represented as Instant (which means it’s inside the bounds of the underlying data structure), None otherwise.

pub fn checked_sub(&self, duration: Duration) -> Option<Instant>

Returns Some(t) where t is the time self - duration if t can be represented as Instant (which means it’s inside the bounds of the underlying data structure), None otherwise.

Trait Implementations

impl Add<Duration> for Instant

type Output = Instant

The resulting type after applying the + operator.

fn add(self, other: Duration) -> Instant

Performs the + operation.

impl AddAssign<Duration> for Instant

fn add_assign(&mut self, rhs: Duration)

Performs the += operation.

impl Clone for Instant

fn clone(&self) -> Instant

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for Instant

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

Formats the value using the given formatter.

impl From<Instant> for Instant

fn from(time: Instant) -> Instant

Performs the conversion.

impl PartialEq<Instant> for Instant

fn eq(&self, other: &Instant) -> bool

This method tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Instant) -> bool

This method tests for !=.

impl PartialOrd<Instant> for Instant

fn partial_cmp(&self, other: &Instant) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

#[must_use]

fn lt(&self, other: &Rhs) -> bool

This method tests less than (for self and other) and is used by the < operator.

#[must_use]

fn le(&self, other: &Rhs) -> bool

This method tests less than or equal to (for self and other) and is used by the <= operator.

#[must_use]

fn gt(&self, other: &Rhs) -> bool

This method tests greater than (for self and other) and is used by the > operator.

#[must_use]

fn ge(&self, other: &Rhs) -> bool

This method tests greater than or equal to (for self and other) and is used by the >= operator.

impl Sub<Duration> for Instant

type Output = Instant

The resulting type after applying the - operator.

fn sub(self, rhs: Duration) -> Instant

Performs the - operation.

impl Sub<Instant> for Instant

type Output = Duration

The resulting type after applying the - operator.

fn sub(self, rhs: Instant) -> Duration

Performs the - operation.

impl SubAssign<Duration> for Instant

fn sub_assign(&mut self, rhs: Duration)

Performs the -= operation.

impl Copy for Instant

impl Eq for Instant

impl StructuralEq for Instant

impl StructuralPartialEq for Instant