7:57 a.m.
Hi all,
I've downloaded Drools fusion sample and started to make some changes to
the code (first of all wipe out the UI so I can test it easier).
I tried to get to a minimal set so I can run a console main class and see
what happens but I am facing a strange behaviour.
As soon as I start pushing events into the WorkingMemoryEntryPoint
("StockTick stream") a Thread - not daemonized since it blocks shutdown from
ending - is spawned and this prevents my JVM from shutting down (obviously
if I call System.exit(0) it will but I am avoiding this).
I've tried both to halt and dispose the session that this entry point
belongs but with no success. Does anyone know how could I get rid of this
thread?
best regards,
--
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10:22 a.m.
Rafael Ribeiro wrote:
Hi all,
I've downloaded Drools fusion sample and started to make some changes to
the code (first of all wipe out the UI so I can test it easier).
I tried to get to a minimal set so I can run a console main class and see
what happens but I am facing a strange behaviour.
As soon as I start pushing events into the WorkingMemoryEntryPoint
("StockTick stream") a Thread - not daemonized since it blocks shutdown from
ending - is spawned and this prevents my JVM from shutting down (obviously
if I call System.exit(0) it will but I am avoiding this).
I've tried both to halt and dispose the session that this entry point
belongs but with no success. Does anyone know how could I get rid of this
thread?
Drools is starting up threads in a number of places now - using "new
Thread()". I think the plan is to change this to an interface call that
allows pluggable implementations. So that the user can decide how
threads are executed and stopped.
Mark
best regards,
11:54 a.m.
Hi Rafael,
Are you setting the MultithreadEvaluation option or is this using default
options? Do you have an example code that shows this behavior?
Thanks,
Edson
2009/7/16 Rafael Ribeiro <rafaelri(a)gmail.com>
Hi all,
I've downloaded Drools fusion sample and started to make some changes to
the code (first of all wipe out the UI so I can test it easier).
I tried to get to a minimal set so I can run a console main class and see
what happens but I am facing a strange behaviour.
As soon as I start pushing events into the WorkingMemoryEntryPoint
("StockTick stream") a Thread - not daemonized since it blocks shutdown
from
ending - is spawned and this prevents my JVM from shutting down (obviously
if I call System.exit(0) it will but I am avoiding this).
I've tried both to halt and dispose the session that this entry point
belongs but with no success. Does anyone know how could I get rid of this
thread?
best regards,
--
12:10 p.m.
Hi Edson!
as I've already mentioned I've modified the sample so, if you get the
StockTick sample and replace the Main class this will run fine.
The sample shuts down fine but as I saw it sets the JFrame uses
frame.setDefaultCloseOperation( WindowConstants.EXIT_ON_CLOSE ); which in
turn makes the trick.
Below the code of my modified main class:
package org.drools.examples.broker;
import org.drools.KnowledgeBase;
import org.drools.KnowledgeBaseConfiguration;
import org.drools.KnowledgeBaseFactory;
import org.drools.builder.KnowledgeBuilder;
import org.drools.builder.KnowledgeBuilderFactory;
import org.drools.builder.ResourceType;
import org.drools.conf.EventProcessingOption;
import org.drools.examples.broker.model.Company;
import org.drools.examples.broker.model.CompanyRegistry;
import org.drools.examples.broker.model.StockTick;
import org.drools.io.ResourceFactory;
import org.drools.runtime.StatefulKnowledgeSession;
import org.drools.runtime.rule.WorkingMemoryEntryPoint;
public class Main {
private static final String RULES_FILE = "/broker.drl";
static StatefulKnowledgeSession session;
static WorkingMemoryEntryPoint tickStream;
/**
* @param args
*/
public static void main(String[] args) throws Exception {
// set up and show main window
CompanyRegistry companies = new CompanyRegistry();
KnowledgeBuilder builder =
KnowledgeBuilderFactory.newKnowledgeBuilder();
try {
builder.add( ResourceFactory.newInputStreamResource(
Main.class.getResourceAsStream( RULES_FILE ) ),
ResourceType.DRL);
} catch ( Exception e ) {
e.printStackTrace();
}
if( builder.hasErrors() ) {
System.err.println(builder.getErrors());
System.exit( 0 );
}
KnowledgeBaseConfiguration conf =
KnowledgeBaseFactory.newKnowledgeBaseConfiguration();
conf.setOption( EventProcessingOption.STREAM );
KnowledgeBase kbase = KnowledgeBaseFactory.newKnowledgeBase( conf );
kbase.addKnowledgePackages( builder.getKnowledgePackages() );
session = kbase.newStatefulKnowledgeSession();
session.setGlobal( "services", new BrokerServices() {
public void log(String message) {
System.out.println(message);
}
});
for( Company company : companies.getCompanies() ) {
session.insert( company );
}
session.fireAllRules();
tickStream = session.getWorkingMemoryEntryPoint( "StockTick stream"
);
for (int i=10;i>0;i--) {
tickStream.insert(new StockTick("RHT", i*10,
System.currentTimeMillis()));
session.getAgenda().getAgendaGroup( "evaluation" ).setFocus();
session.fireAllRules();
}
session.dispose();
session.halt();
System.out.println("Still running...");
}
}
regards,
Rafael Ribeiro
2009/7/16 Edson Tirelli <tirelli(a)post.com>
Hi Rafael,
Are you setting the MultithreadEvaluation option or is this using
default options? Do you have an example code that shows this behavior?
Thanks,
Edson
2009/7/16 Rafael Ribeiro <rafaelri(a)gmail.com>
>
> Hi all,
>
> I've downloaded Drools fusion sample and started to make some changes to
> the code (first of all wipe out the UI so I can test it easier).
> I tried to get to a minimal set so I can run a console main class and see
> what happens but I am facing a strange behaviour.
> As soon as I start pushing events into the WorkingMemoryEntryPoint
> ("StockTick stream") a Thread - not daemonized since it blocks shutdown
> from
> ending - is spawned and this prevents my JVM from shutting down (obviously
> if I call System.exit(0) it will but I am avoiding this).
> I've tried both to halt and dispose the session that this entry point
> belongs but with no success. Does anyone know how could I get rid of this
> thread?
>
> best regards,
> --
>
_______________________________________________
rules-users mailing list
rules-users(a)lists.jboss.org
http://lists.jboss.org/mailman/listinfo/rules-users
9:56 a.m.
The problem here is a different one. The engine is calling shutdown() on
a thread pool and even without any task being executed, the thread is
blocked in an internal JDK queue waiting for the timeout. I replaced the
call by shutdownNow(), forcing the jdk to signal an interrupt to the thread
and this seemed to work. I am investigating side effects of this procedure
right now.
[]s
Edson
2009/7/16 Mark Proctor <mproctor(a)codehaus.org>
Rafael Ribeiro wrote:
> Hi all,
>
> I've downloaded Drools fusion sample and started to make some changes to
> the code (first of all wipe out the UI so I can test it easier).
> I tried to get to a minimal set so I can run a console main class and
see
> what happens but I am facing a strange behaviour.
> As soon as I start pushing events into the WorkingMemoryEntryPoint
> ("StockTick stream") a Thread - not daemonized since it blocks shutdown
from
> ending - is spawned and this prevents my JVM from shutting down
(obviously
> if I call System.exit(0) it will but I am avoiding this).
> I've tried both to halt and dispose the session that this entry point
> belongs but with no success. Does anyone know how could I get rid of this
> thread?
>
Drools is starting up threads in a number of places now - using "new
Thread()". I think the plan is to change this to an interface call that
allows pluggable implementations. So that the user can decide how
threads are executed and stopped.
Mark
> best regards,
>
_______________________________________________
rules-users mailing list
rules-users(a)lists.jboss.org
https://lists.jboss.org/mailman/listinfo/rules-users
--
Edson Tirelli
JBoss Drools Core Development
JBoss by Red Hat @ www.jboss.com
9:59 a.m.
Edson:
Is it a code change inside Drools or is there any other shutdown method
that I may call ?
Mark:
I completely agree with this future change, it makes much sense in an
AppServer environment where we shouldn't be handling thread creation and
disposal by ourselves.
regards,
Rafael
2009/7/17 Edson Tirelli <tirelli(a)post.com>
The problem here is a different one. The engine is calling shutdown()
on a thread pool and even without any task being executed, the thread is
blocked in an internal JDK queue waiting for the timeout. I replaced the
call by shutdownNow(), forcing the jdk to signal an interrupt to the thread
and this seemed to work. I am investigating side effects of this procedure
right now.
[]s
Edson
2009/7/16 Mark Proctor <mproctor(a)codehaus.org>
Rafael Ribeiro wrote:
> > Hi all,
> >
> > I've downloaded Drools fusion sample and started to make some changes
> to
> > the code (first of all wipe out the UI so I can test it easier).
> > I tried to get to a minimal set so I can run a console main class and
> see
> > what happens but I am facing a strange behaviour.
> > As soon as I start pushing events into the WorkingMemoryEntryPoint
> > ("StockTick stream") a Thread - not daemonized since it blocks
shutdown
> from
> > ending - is spawned and this prevents my JVM from shutting down
> (obviously
> > if I call System.exit(0) it will but I am avoiding this).
> > I've tried both to halt and dispose the session that this entry point
> > belongs but with no success. Does anyone know how could I get rid of
> this
> > thread?
> >
> Drools is starting up threads in a number of places now - using "new
> Thread()". I think the plan is to change this to an interface call that
> allows pluggable implementations. So that the user can decide how
> threads are executed and stopped.
>
> Mark
> > best regards,
> >
>
>
> _______________________________________________
> rules-users mailing list
> rules-users(a)lists.jboss.org
> https://lists.jboss.org/mailman/listinfo/rules-users
>
--
Edson Tirelli
JBoss Drools Core Development
JBoss by Red Hat @ www.jboss.com
_______________________________________________
rules-users mailing list
rules-users(a)lists.jboss.org
https://lists.jboss.org/mailman/listinfo/rules-users
10:09 a.m.
Rafael,
It is the JDK class:
Class ScheduledThreadPoolExecutor
Check the API for methods shutdown() and shutdownNow(). I am also looking
at the JDK source code. It seems safe in our case to change the call to
shutdownNow() instead of the previous call to shutdown(). The shutdown is
called on session dispose() only and as so it is an irreversible operation
anyway.
I am just double checking, but I think there is no choice. Brian Goetz's
Java Concurrency in Practice also states that the jdk blocking operations
may or may not be canceled gracefully (case-by-case) on chapter 7.
Give me another hour to make sure everything is ok and I will commit a
fix.
https://jira.jboss.org/jira/browse/JBRULES-2211
[]s
Edson
2009/7/17 Rafael Ribeiro <rafaelri(a)gmail.com>
Edson:
Is it a code change inside Drools or is there any other shutdown method
that I may call ?
Mark:
I completely agree with this future change, it makes much sense in an
AppServer environment where we shouldn't be handling thread creation and
disposal by ourselves.
regards,
Rafael
2009/7/17 Edson Tirelli <tirelli(a)post.com>
> The problem here is a different one. The engine is calling shutdown()
> on a thread pool and even without any task being executed, the thread is
> blocked in an internal JDK queue waiting for the timeout. I replaced the
> call by shutdownNow(), forcing the jdk to signal an interrupt to the thread
> and this seemed to work. I am investigating side effects of this procedure
> right now.
>
> []s
> Edson
>
>
> 2009/7/16 Mark Proctor <mproctor(a)codehaus.org>
>
> Rafael Ribeiro wrote:
>> > Hi all,
>> >
>> > I've downloaded Drools fusion sample and started to make some changes
>> to
>> > the code (first of all wipe out the UI so I can test it easier).
>> > I tried to get to a minimal set so I can run a console main class and
>> see
>> > what happens but I am facing a strange behaviour.
>> > As soon as I start pushing events into the WorkingMemoryEntryPoint
>> > ("StockTick stream") a Thread - not daemonized since it blocks
shutdown
>> from
>> > ending - is spawned and this prevents my JVM from shutting down
>> (obviously
>> > if I call System.exit(0) it will but I am avoiding this).
>> > I've tried both to halt and dispose the session that this entry point
>> > belongs but with no success. Does anyone know how could I get rid of
>> this
>> > thread?
>> >
>> Drools is starting up threads in a number of places now - using "new
>> Thread()". I think the plan is to change this to an interface call that
>> allows pluggable implementations. So that the user can decide how
>> threads are executed and stopped.
>>
>> Mark
>> > best regards,
>> >
>>
>>
>> _______________________________________________
>> rules-users mailing list
>> rules-users(a)lists.jboss.org
>> https://lists.jboss.org/mailman/listinfo/rules-users
>>
>
>
>
> --
> Edson Tirelli
> JBoss Drools Core Development
> JBoss by Red Hat @ www.jboss.com
>
> _______________________________________________
> rules-users mailing list
> rules-users(a)lists.jboss.org
> https://lists.jboss.org/mailman/listinfo/rules-users
>
>
_______________________________________________
rules-users mailing list
rules-users(a)lists.jboss.org
https://lists.jboss.org/mailman/listinfo/rules-users
--
Edson Tirelli
JBoss Drools Core Development
JBoss by Red Hat @ www.jboss.com
5411
days inactive
5412
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6 comments
3 participants
participants (3)
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Edson Tirelli -
Mark Proctor -
Rafael Ribeiro