環境

• Time 2022-01-11
• Rust 1.57.0
• Tokio 1.15.0

概念

參考：https://docs.rs/tokio/latest/tokio/time/index.html

示例

interval

use std::{io, thread, time::Duration};

use tokio::time::{self, Instant};

#[tokio::main]
async fn main() -> io::Result<()> {

let start = Instant::now() + Duration::from_millis(50);
    let mut interval = interval_at(start, Duration::from_millis(200));
    for _i in 0..5 {
        interval.tick().await;
        async {
            println!("{}", thread::current().name().unwrap());
            println!("elapsed: {} ms", now.elapsed().as_millis())
        }
        .await;
    }

    Ok(())
}
 

interval_at

use std::{io, thread};

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

#[tokio::main]
async fn main() -> io::Result<()> {
    let start = Instant::now() + Duration::from_secs(4);
    // 四秒後，每兩百毫秒執行一次
    let mut interval = time::interval_at(start, Duration::from_millis(200));
    for _i in 0..5 {
        interval.tick().await;
        async {
            println!("{}", thread::current().name().unwrap());
        }
        .await;
    }

    Ok(())
}
 

總結

通過 interval 和 interval_at 來定義非同步的週期性任務。

附錄