The
Cancel-Correct
Async Runtime.

01
use asupersync::{Region, Cx, Outcome, Budget};02
use std::time::Duration;03 04#[asupersync::main]05
async 
fn main(cx: &Cx) -> Outcome<()> {06    // Open a region — all tasks scoped here07    Region::open(cx, "server", 
async |cx| {08        // Spawn a listener with cancel capability09        
let permit = cx.spawn("listener", 
async |cx| {10            
let listener = cx.tcp_bind("0.0.0.0:8080").
await?;11            
loop {12                
let (stream, _) = listener.accept(cx).
await?;13                cx.spawn("conn", handle_connection(stream));14            }15        });16 17        // Wait for shutdown signal18        cx.shutdown_signal().
await;19 20        // Cancel with budget — tasks get 5s to drain21        permit.cancel(Budget::timeout(Duration::from_secs(5)));22    }).
await23}