addShutdownHook

fun ApplicationEngine.addShutdownHook(stop: () -> Unit): Unit

Adds automatic JVM shutdown hooks management. Should be used before starting the engine. Once JVM termination noticed, stop block will be executed. Please note that a shutdown hook only registered when the application is running. If the application is already stopped then there will be no hook and no stop function invocation possible. So stop block will be called once or never.