Crate async_rs 

A Rust async runtime abstraction library.

Provides a unified Runtime enum and a set of traits (Executor, Reactor, Dns, …) that abstract over Tokio, smol, and async-global-executor. Applications select exactly one runtime via feature flags; library crates depend on the trait objects and remain runtime-agnostic.

Feature flags

Flag	Notes
tokio (default)	Tokio runtime
smol	smol executor
async-global-executor	async-global-executor
async-io	async-io reactor (required by smol)
hickory-dns	Hickory DNS resolver (tokio only)

Example

use async_rs::{Runtime, TokioRuntime, traits::*};
use std::{io, time::Duration};

async fn get_a(rt: &TokioRuntime) -> io::Result<u32> {
    rt.spawn_blocking(|| Ok(12)).await
}

async fn get_b(rt: &TokioRuntime) -> io::Result<u32> {
    rt.spawn(async { Ok(30) }).await
}

async fn tokio_main(rt: &TokioRuntime) -> io::Result<()> {
    let a = get_a(rt).await?;
    let b = get_b(rt).await?;
    rt.sleep(Duration::from_millis(500)).await;
    assert_eq!(a + b, 42);
    Ok(())
}

fn main() -> io::Result<()> {
    let rt = Runtime::tokio()?;
    rt.block_on(tokio_main(&rt))
}

Modules

traits

A collection of traits to define a common interface across async runtimes

util

A collection of utilities to deal with IO, futures and runtimes

Structs

AsyncGlobalExecutor

Dummy object implementing executor common interfaces on top of async-global-executor

AsyncIO

Dummy object implementing reactor common interfaces on top of async-io

HickoryToSocketAddrs

Perform async DNS resolution using hickory-dns

Noop

Dummy object implementing async common interfaces on top of noop

Runtime

A full-featured Runtime implementation

Smol

Dummy object implementing async common interfaces on top of smol

Tokio

Dummy object implementing async common interfaces on top of tokio

Type Aliases

AGERuntime

Type alias for the async-global-executor runtime

NoopRuntime

Type alias for the noop runtime

SmolRuntime

Type alias for the smol runtime

TokioRuntime

Type alias for the tokio runtime