How to shutdown IronJacamar embedded properly ?

[sewatech]

Hi,

When I shutdown IronJacamar embedded, some non-daemon threads are kept alive. That's a real problem when I try to embed IJ in a webapp.

Here is the simpler exemple that shows my problem :

public static void main(String[] args) throws Throwable {

   System.setProperty(Context.INITIAL_CONTEXT_FACTORY, "org.jnp.interfaces.LocalOnlyContextFactory");
   System.setProperty(Context.URL_PKG_PREFIXES, "org.jboss.naming:org.jnp.interfaces");

   Set<Thread> initialThreads = Thread.getAllStackTraces().keySet();

   Embedded embedded = EmbeddedFactory.create();
   embedded.startup();
   embedded.shutdown();

   Set<Thread> finalThreads = Thread.getAllStackTraces().keySet();
   finalThreads.removeAll(initialThreads);

   finalThreads.forEach(thread -> System.out.println(thread.getThreadGroup().getName() + "/" + thread.getName()));
}

Is their a way to initialize or shutdown IJ in order to avoid this thread problem ?

Alexis

[maeste]

Hi,

which version of IronJacamar are you using? Would you please paste here the result of your println cycle?

Thanks

S.

[sewatech]

Hi Stefano,

I'm using IronJacamar 1.3.4.Final.

Here is my output :

fungal/Listener:55030

[java.net.PlainSocketImpl.socketAccept(Native Method), java.net.AbstractPlainSocketImpl.accept(AbstractPlainSocketImpl.java:409), java.net.ServerSocket.implAccept(ServerSocket.java:545), java.net.ServerSocket.accept(ServerSocket.java:513), com.arjuna.ats.internal.arjuna.recovery.Listener.run(Listener.java:122)]

fungal/pool-1-thread-1

[sun.misc.Unsafe.park(Native Method), java.util.concurrent.locks.LockSupport.park(LockSupport.java:175), java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject.await(AbstractQueuedSynchronizer.java:2039), java.util.concurrent.LinkedBlockingQueue.take(LinkedBlockingQueue.java:442), java.util.concurrent.ThreadPoolExecutor.getTask(ThreadPoolExecutor.java:1067), java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1127), java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617), java.lang.Thread.run(Thread.java:745)]

fungal/Transaction Reaper

[java.lang.Object.wait(Native Method), com.arjuna.ats.internal.arjuna.coordinator.ReaperThread.run(ReaperThread.java:90)]

fungal/Transaction Reaper Worker 0

[java.lang.Object.wait(Native Method), java.lang.Object.wait(Object.java:502), com.arjuna.ats.arjuna.coordinator.TransactionReaper.waitForCancellations(TransactionReaper.java:328), com.arjuna.ats.internal.arjuna.coordinator.ReaperWorkerThread.run(ReaperWorkerThread.java:65)]

system/RMI TCP Accept-0

[java.net.PlainSocketImpl.socketAccept(Native Method), java.net.AbstractPlainSocketImpl.accept(AbstractPlainSocketImpl.java:409), java.net.ServerSocket.implAccept(ServerSocket.java:545), java.net.ServerSocket.accept(ServerSocket.java:513), sun.rmi.transport.tcp.TCPTransport$AcceptLoop.executeAcceptLoop(TCPTransport.java:400), sun.rmi.transport.tcp.TCPTransport$AcceptLoop.run(TCPTransport.java:372), java.lang.Thread.run(Thread.java:745)]

It appears that fungal/pool-1-thread-1 is the only non-daemon one.

Alexis

[sewatech]

In the meanwhile, I've tried some workaround.

First with some code :

ThreadPoolExecutor lookupPool = embedded.lookup("LookupPool", ThreadPoolExecutor.class);
embedded.shutdown();
lookupPool.shutdown();

Or with some configuration, and redefining the naming.xml file, and adding a destroy element on the LookupPool bean :

  <bean name="LookupPool">
    <constructor factoryMethod="newFixedThreadPool"
                 factoryClass="java.util.concurrent.Executors">
      <parameter>2</parameter>
    </constructor>
    <destroy method="shutdown"/>
  </bean>

Both solutions seem to be working, but I've no idea whether it have side effects.

Alexis

[jesper.pedersen]

Yes, beans backed by a thread pool should have the "<destroy method="shutdown"/>" element defined.

Feel free to open a JBJCA JIRA for this, and thanks for investigating !

[sewatech]

Done : [JBJCA-1326] naming.xml : the LookupPool bean should have a destroy element - JBoss Issue Tracker

With a PR : Add destroy on LookupPool by hasalex · Pull Request #530 · ironjacamar/ironjacamar · GitHub

[maeste]

Merged your PR on master

https://github.com/ironjacamar/ironjacamar/commit/c8a331d1f5b0b1df60bcbae1cfb3a424f4cbb453

and backported also into 1.2 branch

https://github.com/ironjacamar/ironjacamar/commit/76d07d21e97eae656246f213fce0ba3caf520fc5

Thanks for the interest and PR

regards

S.