[FELIX-4374] IPOJO: ConcurrentModificationException in ProvidedService

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: ipojo-runtime-1.11.0
• Fix Version/s: ipojo-runtime-1.11.1
• Component/s: iPOJO
• Environment: Karaf 2.3.3
• Assignee: Clement Escoffier
• Reporter: Klaus Schröder
• Created: 06/Jan/14 08:03
• Updated: 07/Mar/14 08:27
• Resolved: 06/Jan/14 10:43

Description

I have a problem with a ManagedServices and IPOJO.
We have a service that provides externally configured properties. We want to use the managed service approach to get automatic refreshs of changed properties. The properties are read from a file

{karaf}

/etc/na.default.properties containing ~500 properties and are injected into the service by @Updated, see code below.
Basically the code works fine, but from time to time the service startup fails with a ConcurrentModificationException in class ProvidedService. The exception does not show always, but it is reproducible by starting and stopping the bundle various times. The code has been stripped down to be very simple and the problem could still be reproduced.

IPOJO version is 1.11.0, Karaf version 2.3.3

Short stacktrace:

2014-01-03 16:17:41,357 | INFO  |  pool-1-thread-1 | product-properties-services      | ?                                   ? | 64 - product-properties-services - 0.0.1.SNAPSHOT | [INFO] com.nextaudience.clustor.product.properties.services.DefaultPropertiesResolverService : An error occurred when creating an instance of com.nextaudience.clustor.product.properties.services.DefaultPropertiesResolverService 
java.util.ConcurrentModificationException 
        at java.util.TreeMap$PrivateEntryIterator.nextEntry(TreeMap.java:1115)[:1.7.0_45] 
        at java.util.TreeMap$ValueIterator.next(TreeMap.java:1160)[:1.7.0_45] 
        at org.apache.felix.ipojo.handlers.providedservice.ProvidedService.getServiceProperties(ProvidedService.java:447)[55:org.apache.felix.ipojo:1.11.0] 
        at org.apache.felix.ipojo.handlers.providedservice.ProvidedService.registerService(ProvidedService.java:357)[55:org.apache.felix.ipojo:1.11.0] 
        at org.apache.felix.ipojo.handlers.providedservice.ProvidedServiceHandler.__M_stateChanged(ProvidedServiceHandler.java:484)[55:org.apache.felix.ipojo:1.11.0] 
        at org.apache.felix.ipojo.handlers.providedservice.ProvidedServiceHandler.stateChanged(ProvidedServiceHandler.java)[55:org.apache.felix.ipojo:1.11.0] 
        at org.apache.felix.ipojo.InstanceManager.setState(InstanceManager.java:536)[55:org.apache.felix.ipojo:1.11.0] 
        at org.apache.felix.ipojo.InstanceManager.start(InstanceManager.java:418)[55:org.apache.felix.ipojo:1.11.0] 
        at org.apache.felix.ipojo.ComponentFactory.createInstance(ComponentFactory.java:179)[55:org.apache.felix.ipojo:1.11.0] 
        at org.apache.felix.ipojo.IPojoFactory.createComponentInstance(IPojoFactory.java:319)[55:org.apache.felix.ipojo:1.11.0] 
        at org.apache.felix.ipojo.IPojoFactory.createComponentInstance(IPojoFactory.java:240)[55:org.apache.felix.ipojo:1.11.0] 
        at org.apache.felix.ipojo.extender.internal.linker.ManagedType$InstanceSupport$1.call(ManagedType.java:312)[55:org.apache.felix.ipojo:1.11.0] 
        at org.apache.felix.ipojo.extender.internal.linker.ManagedType$InstanceSupport$1.call(ManagedType.java:306)[55:org.apache.felix.ipojo:1.11.0] 
        at org.apache.felix.ipojo.extender.internal.queue.JobInfoCallable.call(JobInfoCallable.java:114)[55:org.apache.felix.ipojo:1.11.0] 
        at java.util.concurrent.FutureTask.run(FutureTask.java:262)[:1.7.0_45] 
        at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)[:1.7.0_45] 
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)[:1.7.0_45] 
        at java.lang.Thread.run(Thread.java:744)[:1.7.0_45] 
2014-01-03 16:17:41,357 | ERROR |  pool-1-thread-1 | product-properties-services      | ?                                   ? | 64 - product-properties-services - 0.0.1.SNAPSHOT | [ERROR] com.nextaudience.clustor.product.properties.services.DefaultPropertiesResolverService : null 

Our service:

{code
@Component(managedservice = "na.default.properties", publicFactory = false)
@Instantiate
@Provides
public class DefaultPropertiesResolverService implements ObservablePropertiesResolver {

private static final Logger LOG = LoggerFactory.getLogger(DefaultPropertiesResolverService.class);

@ServiceController
private boolean ready;
private Dictionary<String, String> properties;

@Validate
synchronized private void startService() {
LOG.info("startService start...");
if (getProperties() == null)

{ LOG.warn("No properties for " + getClass().getName()); return; }

if (getProperties().isEmpty())

{ LOG.warn("Empty properties for " + getClass().getName()); return; }

ready = true;
LOG.info(DefaultPropertiesResolverService.class.getName() + "::Start");
}

@Invalidate
synchronized private void stopService()

{ ready = false; LOG.info(DefaultPropertiesResolverService.class.getName() + "::Stop"); }

synchronized public Dictionary<String, String> getProperties()

{ return properties; }

@Updated
synchronized public void updateLocalProperties(Dictionary<String, String> cfgProperties)

{ LOG.info("DefaultProperties: updateLocalProperties start..."); properties = cfgProperties; LOG.info("DefaultProperties: updateLocalProperties end"); }

}
{code