simple_on_shutdown

This Rust library consists of a convenient macro to specify on shutdown callbacks. This is useful for all runtimes you do not have control over.

The generated main() function of an "actix" web server is a good example. With the exported macro on_shutdown!() you can easily specify code, that should run during program termination/shutdown.

IMPORTANT: Use this on the top level of your main() or whatever your current runtimes main function is! The code gets executed when the context it lives in gets dropped. This can be called multiple times (at least with stable Rust 1.48.0) without problem.

Usage

Recommended

use simple_on_shutdown::on_shutdown;
// ...
on_shutdown!(println!("shutted down"));

Not recommended, old way

// Not recommended, old way
#[macro_use]
extern crate simple_on_shutdown;
// ...
on_shutdown!(println!("shutted down"));

Simple Example

See also "example/"-dir in repository!

use simple_on_shutdown::on_shutdown;

fn main() {
    // some code ...
    
    // Important that the returned value of the macro lives through
    // the whole lifetime of main(). It gets dropped in the end.
    on_shutdown!(println!("shut down with success"));
    // some code ...
}

Actix Web Server

See also "example/"-dir in repository!

use actix_web::{get, HttpServer, App, HttpResponse, Responder};
use simple_on_shutdown::on_shutdown;

#[get("/")]
async fn get_index() -> impl Responder {
    HttpResponse::Ok().body("Hello World")
}

#[actix_web::main]
async fn main() -> std::io::Result<()> {
    // Important that the returned value of the macro lives through
    // the whole lifetime of main(). It gets dropped in the end.
    on_shutdown!({
                // the actual code
                println!("This gets executed during shutdown. Don't to expensive operations here.");
    });

    HttpServer::new(|| {
        App::new()
            .service(get_index)
    })
        .bind(format!("localhost:{}", 8080))?
        .run()
        .await
}