None exist error code after a graceful shutdown

Question

I'd like to return a none zero exit code after a normal graceful shutdown.
My end task is to be able to send a restart event to a number of machines running my application that will gracefully shutdown and inform the shell script that started it that it wants to be restarted.
One option would be System.exit with a shutdown hook that monitors the current threads, and does not end until the other threads have also exited, but I would have to inform this hook of threads that should be allowed to finish naturally. But that seams a little [t]icky.
I guess I could write to a file, and then close down naturally. But this leaves files drifting about. I'm not overly keen on that either.
Any other suggestions? Thanks, Mike

Answer 1

The "worker" thread should
not be interupted, and told to exit, just left to
exit under there own steam. (when they have finished
the current job). What is the "worker" thread ? Is it what I meant with "watcher" thread ? Is that what you said or what I said ?
And, I assumed we are talking about a server-like application, that is one running indefinitely, as opposed to one that would perform a specific task and then terminate. Am I correct ?
The initalization of this new type of
shutdown/restart is currently undefined, but will
likely that the application start listening on a
socket connection. I'm sorry, I don't understand that at all.
I want this to ease deployment,
currently when I deploy a new version I type "ant
deploy", then VNC on to each of the computer
(currently just 3, but likely to be more soon) and
manually restart. What I want is to just type "ant
deploy" it sends a signal to the running copies, and
they restart themselfs. (I'm a lazy brsatard).You know this quote by Larry Wall (?) about the three most important characteristics of a programmer, don't you ?
>
and thus the exit code is already defined.Not so with what I would consider a "graceful
shutdown". Then the application would shut down as
all the threads have completed.It depends on whether having "all threads completed" is a normal part of the application's flow. If I assumed correctly we were talking about a server-like app, then it's not. Ergo the command to terminate has to be issued at some point. The question is how that gets done. For instance, if you send a CTRL-C from the shell, your application shuts down with an error code != 0.
A graceful shutdown needs to be initiated somewhere. How do you plan to do it ?