Crate graceful_shutdown
source ·Expand description
A library to make it easier to handle graceful shutdowns in async code.
This provides tools to wait for pending tasks to complete before finalizing shutdown.
Examples
use graceful_shutdown::Shutdown;
use tokio::io::{AsyncReadExt, AsyncWriteExt};
use tokio::net::TcpListener;
use tokio::signal;
use tokio::{select, spawn};
#[tokio::main]
async fn main() -> Result<(), Box<dyn std::error::Error>> {
let shutdown = Shutdown::new();
let listener = TcpListener::bind("127.0.0.1:8000").await?;
spawn(shutdown.shutdown_after(signal::ctrl_c()));
loop {
match shutdown.cancel_on_shutdown(listener.accept()).await {
Some(Ok((mut conn, _))) => {
spawn(shutdown.graceful(async move {
let mut buf = [0; 1024];
loop {
let n = match conn.read(&mut buf).await {
Ok(n) if n == 0 => return,
Ok(n) => n,
Err(e) => {
eprintln!("failed to read from socket; err = {:?}", e);
return;
}
};
if let Err(e) = conn.write_all(&buf[0..n]).await {
eprintln!("failed to write to socket; err = {:?}", e);
return;
}
}
}));
}
Some(Err(e)) => {
eprintln!("Error accepting connection; err = {:?}", e);
shutdown.shutdown();
}
None => {
eprintln!("Starting shutdown");
break;
}
}
}
shutdown.await;
Ok(())
}
Structs
A future that is canceled if shutdown is initiated.
A drop guard to prevent final shutdown.
Future that prevents shutting down until the wrapped future completes.
Future for graceful shutdown.
Future for waiting for a shutdown with an escape hatch terminating condition.