Introduce an exit request API with wait-for-exit method

[dmlloyd]

Description
Introduce an exit request API with wait-for-exit method. Methods should be defined as follows:

• A method to request that the application exit with a given exit code (non blocking) (e.g. requestExit(int); code must be between 0 and 255 (inclusive))
• A method to request that the application exit with no code (0 is implied) (non blocking) (e.g. requestExit())
• A method to wait for an exit request; this method returns the requested exit code (blocking) (e.g. awaitExit())

[gastaldi]

Dumb question, but after the application exits, what is a valid use case for awaitExit()?

[dmlloyd]

The awaitExit method would be used to wait for someone to call requestExit. Once exit is requested, awaitExit returns the requested exit code.

[ToWipf]

My way to stop the application:

private boolean bShutdown = false;

@Override
public int run(String... args) throws Exception {
	LOGGER.info("start");
	while (true) {
		Thread.sleep(1000);
		if (bShutdown) {
			LOGGER.info("stop");
			return 0;
		}
	}
}

public void stopApp() {
	this.bShutdown = true;
}

[stuartwdouglas]

This is present in Quarkus.waitForExit and Quarkus.asyncExit