JVM termination, daemon threads

[wytten]

Day 1 of Spring Integration here...I've got a simple directory monitor working but the JVM doesn't exit when I interrupt the main thread with Control-C. I tried specifying daemon=false as described here but that had no effect.

My configuration (with failed attempt at daemon=false) is as follows. What configuration do I need to make the JVM exit?

	
	<int:channel id="fileChannel" datatype="java.io.File">
		<int:dispatcher task-executor="fileChannelTaskExecutor" />
	</int:channel>

	<bean id="fileChannelTaskExecutor"
		class="org.springframework.scheduling.concurrent.ThreadPoolTaskExecutor">
		<property name="corePoolSize" value="2"/>
		<property name="daemon" value="false"/>
	</bean>	

	<int:poller default="true" max-messages-per-poll="1"
		fixed-rate="1000" />

	<int-file:inbound-channel-adapter 
		directory="file:c:/watch" channel="fileChannel" prevent-duplicates="true" />

	<int:outbound-channel-adapter channel="fileChannel" 
		ref="target" method="handleMessage" >
	</int:outbound-channel-adapter>

	<bean id="target" class="...

[Gary Russell]

Can you attach a thread dump? (I think it's Ctrl-Break on Windows, but you can use jstack or VisualVM too).

[jim_doyle]

I have no problems with CTRL-C ; but I am an using a JVM Shutdown and a Spring Context Listener Shutdown hook. The
JVM Shutdown will tell Spring to close... The Spring Context listener will tell the Sched/Executor to passivate. Seems to work for me!

class Main {
  private static ClassPathXmlApplicationContext springCtx;
  public static void main(String [] args) {

    // Create a global shutdown handler to take down the Spring Container
    Runtime.getRuntime().addShutdownHook(new Thread() {
            public void run() {
                if (springCtx != null) {
                    springCtx.close();
                }
                log.info("*** Started Spring shutdown...");
            }
        });

        // Bootstrap Spring Container
        springCtx = new ClassPathXmlApplicationContext(new String[]{
                    "nbpump-spring-context.xml",
                    "activemq-jms-config.xml"
                });
        // When the Spring Container is told to shutdown, add a Listener to terminate the Task Scheduler and its thread pool
        springCtx.addApplicationListener(new TaskSchedulerShutdownHandler());
       //
       //  The rest of your main method goes here
  }

  // Task Shutdown handler - uses static Spring Context to locate Task Scheduler and Executor and take it down easy.
static class TaskSchedulerShutdownHandler implements ApplicationListener<ContextClosedEvent> {
        public void onApplicationEvent(ContextClosedEvent event) {
            ThreadPoolTaskExecutor executor = springCtx.getBean(ThreadPoolTaskExecutor.class);
            ThreadPoolTaskScheduler scheduler = springCtx.getBean(ThreadPoolTaskScheduler.class);
            if (executor != null) {
                executor.shutdown();
            }
            if (scheduler != null) {
                scheduler.shutdown();
            }
            log.info("*** Shutdown Spring scheduler and executor...");
        }
    }

[wytten]

Can you attach a thread dump? (I think it's Ctrl-Break on Windows, but you can use jstack or VisualVM too).

Thanks for the push in the right direction; it turns out this had nothing to do with threads.
I had been starting the windows cmd shell with Cygwin shell as parent process. Turns out
I can't interrupt any Java process with a cmd shell started that way. If I start cmd shell
the ordinary way, everything works fine.