[icedtea-web] not closeable javaws (and maybe more)

[Jie Kang]

----- Original Message -----
> On 02/18/2015 03:23 PM, Jie Kang wrote:
> >
> >
> > ----- Original Message -----
> >> On 02/17/2015 11:57 AM, Jiri Vanek wrote:
> >>> On 02/17/2015 11:00 AM, Jiri Vanek wrote:
> >>>> Hi!
> >>>>
> >>>> Head, for already some time javaws apps needs to be closed by signal
> >>>> kill.
> >>>> For long time I thought this is soem accident or whatever, but it is
> >>>> not.
> >>>> Today I tracked it to guilty changeset of
> >>>> http://icedtea.classpath.org/hg/icedtea-web/rev/6f4c1d501560
> >>>>
> >>>> Looking for the fix now, but in case I fail, this will spare some time
> >>>> to
> >>>> the followr,
> >>>>
> >>>>    J.
> >>>
> >>> Ok, so the caus eis clear, ServiceExecutor do not run as daemon, and so
> >>> is
> >>> preventing jvm to stop.
> >>>
> >>> I'm wondering Why I dont see this issue from plugin side...
> >>>
> >>> Anyway - for javaws - both ok and failed run - where to place call to
> >>>
> >>> diff -r a8baec8d9d21 netx/net/sourceforge/jnlp/cache/ResourceTracker.java
> >>> --- a/netx/net/sourceforge/jnlp/cache/ResourceTracker.java    Fri Feb 13
> >>> 12:48:24 2015 +0100
> >>> +++ b/netx/net/sourceforge/jnlp/cache/ResourceTracker.java    Tue Feb 17
> >>> 11:57:01 2015 +0100
> >>> @@ -34,6 +34,7 @@
> >>>    import java.util.List;
> >>>    import java.util.concurrent.ExecutorService;
> >>>    import java.util.concurrent.Executors;
> >>> +import java.util.concurrent.TimeUnit;
> >>>
> >>>    import net.sourceforge.jnlp.DownloadOptions;
> >>>    import net.sourceforge.jnlp.Version;
> >>> @@ -633,4 +634,15 @@
> >>>        interface Filter<T> {
> >>>            public boolean test(T t);
> >>>        }
> >>> +
> >>> +    public static void shutdDownThreadPool() throws
> >>> InterruptedException{
> >>> +        threadPool.shutdown();
> >>> +        if (!threadPool.awaitTermination(5, TimeUnit.SECONDS)) {
> >>> +            OutputController.getLogger().log("Executor did not terminate
> >>> in the specified time.");
> >>> +            List<Runnable> droppedTasks = threadPool.shutdownNow();
> >>> +            OutputController.getLogger().log("Executor was abruptly shut
> >>> down. " + droppedTasks.size() + " tasks will not be executed.");
> >>> +        }
> >>> +    }
> >>> +
> >>> +
> >>>    }
> >>>
> >>>
> >>> ?
> >>
> >> One more thought, attached patch fixed the issue for me:
> >>
> >> It does only thing - it changes threads used by ExecutorService to
> >> daemons.
> >>
> >> Well, I dont know whot Iahve done - I dont know if ExecutorService is
> >> still
> >> keeping its purpose when its threads are daemons.
> >>
> >> On contrary, documentation is silent, and usage of custom ThreadFactory is
> >> supported....
> >> As negativism, original code (before patch 6f4c1d501560) was not using
> >> daemons. But was not recycling threads...
> >>
> >>
> >> Thoughts?
> >
> > Hello,
> >
> > I strongly prefer a solution that uses threadPool.shutdown() since it is
> > the proper way to stop the service and generally much more
> > predictable/safer solution.
> 
> I'm the opposite. I consider this as much safer ad more predictable
> approach...


By making them daemon threads they are discarded on exit. How is this EVER safe or predictable?


[1] http://crunchify.com/what-is-daemon-thread-in-java-example-attached/
[2] http://stackoverflow.com/questions/2213340/what-is-daemon-thread-in-java

"stacks are not unwound - the JVM just exits", "finally blocks are not executed"

> 
> >
> > How about using a ResourceTracker Factory to create ResourceTrackers and
> > keep a list of them there. Then you can call the shutdown on all the
> > ResourceTrackers when IT-W exits.
> 
> Again - when/where is that point where to call this "shutdown" ? Such a point
> do not exists in
> plugin, and is achiavable by many paths from javaws....

JNLPRuntime:

        Runtime.getRuntime().addShutdownHook(new Thread("JNLPRuntimeShutdownHookThread") {
            public void run() {
                markNetxStopped();
                CacheUtil.cleanCache();
            }
        });

Does this shutdown hook not work?

> 
> Also - the service is static, so no need to track it...
> 
> J:(
> 
> 
> 


Regards,


-- 

Jie Kang

OpenJDK Team - Software Engineering Intern