CODEWITHSUNDEEP
javaconsoleshutdown-hook
user590444
user590444

Reputation: 4322

How does CTRL-C work with Java program

When I press ctrl-c in console in what sequence are application threads stopped and shutdown hooks called?

Upvotes: 15

Views: 13566

Answers (2)

Stephen C
Stephen C

Reputation: 718826

According to the javadocs, the registered shutdown hooks are called in an unspecified order when the JVM starts shutting down; e.g. in response to a CTRL-C.

Application threads are not "stopped" in any well defined way. Indeed, they could continue running up right until the process exits.

If you want your threads to be shut down in an orderly fashion, you need to do something in a shutdown hook to cause this to happen. For example, a shutdown hook could call Thread.interrupt() to tell worker threads to stop what they are doing ... and call join() to make sure that it has happened.

Upvotes: 12

Martijn Courteaux
Martijn Courteaux

Reputation: 68847

I know that you can specify what should happen when Ctrl-C is being hit by adding a shutdown hook. But I'm not sure in what order.

private static void createShutDownHook()
{
    Runtime.getRuntime().addShutdownHook(new Thread(new Runnable()
    {

        @Override
        public void run()
        {
            System.out.println();
            System.out.println("Thanks for using the application");
            System.out.println("Exiting...");

        }
    }));
}

Upvotes: 5

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