simple-sigh

A simple signal handler.

lib.rs:

A simple signal handler.

On unix, register SIGINT/SIGTERM signal handlers that call a closure to process the signals. On Windows, register "console control" handlers to call a closure on Ctrl+C, Ctrl+Break and close events.

The closure is called once and it is assumed that it will cause the application to terminate.

Usage

The application must call [init()] early (before setting up any other signal handlers or spawning threads). After init() has been called, it must call [register()] to set the callback closure that will be called when one of the signals of interest is raised.

Waiting for termination requests

Applications that are run on spawned threads can use signaling mechanisms like a Condvar or a channel to signal from the signal handler to main() that the application should be terminated. However, because it is assumed that this is a somewhat common use-case for simple-sigh it provides a pre-baked solution for this pattern: init() returns a KillWait object that has a [KillWait::wait()] method that will block indefinitely and wait for the signal handler to trigger.

fn main() {
  let kw = simple_sigh::init().unwrap();

  // .. spawen application thread here ..

  // Set a signal handler callback
  simple_sigh::register(move |_| {
    println!("Received signal");
    // .. signal application runtime to terminate here ..
  })
  .unwrap();

  // Wait for some kind of abortion signal to be received
  println!("Wait for interrupt/termination signal..");
  kw.wait();
  println!("Bye!");
}

Known limitations

simple-sigh isn't intended for production; it was originally designed for use in examples, and it may be lossy with regards to error handling. The general rule is that simple-sigh belongs in dev-dependencies rather than dependencies.