async-io

Async I/O and timers.

This crate provides two tools:

• Async, an adapter for standard networking types (and [many other] types) to use in async programs.
• Timer, a future that expires at a point in time.

For concrete async networking types built on top of this crate, see [async-net].

Implementation

The first time Async or Timer is used, a thread named "async-io" will be spawned. The purpose of this thread is to wait for I/O events reported by the operating system, and then wake appropriate futures blocked on I/O or timers when they can be resumed.

To wait for the next I/O event, the "async-io" thread uses [epoll] on Linux/Android/illumos, [kqueue] on macOS/iOS/BSD, [event ports] on illumos/Solaris, and [IOCP] on Windows. That functionality is provided by the [polling] crate.

However, note that you can also process I/O events and wake futures on any thread using the block_on() function. The "async-io" thread is therefore just a fallback mechanism processing I/O events in case no other threads are.

Examples

Connect to example.com:80, or time out after 10 seconds.

```rust use asyncio::{Async, Timer}; use futureslite::{future::FutureExt, io};

use std::net::{TcpStream, ToSocketAddrs}; use std::time::Duration;

let addr = "example.com:80".tosocketaddrs()?.next().unwrap();

let stream = Async::::connect(addr).or(async { Timer::after(Duration::from_secs(10)).await; Err(io::ErrorKind::TimedOut.into()) }) .await?; ```

License

Licensed under either of

• Apache License, Version 2.0 (LICENSE-APACHE or http://www.apache.org/licenses/LICENSE-2.0)
• MIT license (LICENSE-MIT or http://opensource.org/licenses/MIT)

at your option.

Contribution

Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in the work by you, as defined in the Apache-2.0 license, shall be dual licensed as above, without any additional terms or conditions.