异步客户端

[dev-dependencies]
lager = { package = "lager-net", version = "0.4", default-features = false, features = ["async"] }
tokio = { version = "1", features = ["macros", "rt-multi-thread"] }

use lager::AsyncLagerBox;

#[tokio::test]
async fn rail_comes_up() -> lager::Result<()> {
    let lager = AsyncLagerBox::from_env()?;      // not async
    let supply = lager.supply("supply1");        // not async

    supply.set_voltage(3.3).await?;
    supply.enable().await?;
    let state = supply.state().await?;
    assert_eq!(state.enabled, Some(true));

    supply.disable().await
}

let lager = AsyncLagerBox::from_env()?;         // fan out reads
let blocking = lager::LagerBox::from_env()?;    // for the UART session
let mut uart = blocking.uart("uart1")?;

// Three different instruments: genuinely parallel.
// Bind the handles first -- a handle created inline is a temporary, and the
// future borrows it, so `try_join!` on inline constructors will not borrow-check.
let adc = lager.adc("adc1");
let tc = lager.thermocouple("tc1");
let meter = lager.watt_meter("watt1");

let (v, temp, power) = tokio::try_join!(
    adc.read(),
    tc.read(),
    meter.power(0.5),
)?;