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https://issues.apache.org/jira/browse/FELIX-4297?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13808839#comment-13808839
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David Jencks commented on FELIX-4297:
-------------------------------------
Looking hard at the new logs I found what I think the problem is, I added a
test case demonstrating.
Component FactoryClient has references to a factory component
(ComponentFactory) and also a multiple reference to the service the component
factory creates with newInstance. The ComponentFactory reference is first in
the xml descriptor so is opened first. The setFactory method calls newInstance
on the factory, creating a service which results in a service event for the
other bind method. Since we're still in the first bind method for the factory,
the edgeInfo for the 2nd reference hasn't even had the open tracking count set,
and can't possibly get it's open latch counted down... that happens later when
the 2nd dependency manager is opened.
The solution is to notice that if the open tracking count is not set, then the
tracking count from the service event must be out of range since the tracker
has recorded it and sometime later the open will be set to the highest tracking
count the tracker has recorded.
rev 1536996
> [DS] timing hole in opening a dependency manager
> ------------------------------------------------
>
> Key: FELIX-4297
> URL: https://issues.apache.org/jira/browse/FELIX-4297
> Project: Felix
> Issue Type: Bug
> Components: Declarative Services (SCR)
> Affects Versions: scr-1.8.0
> Reporter: David Jencks
> Assignee: David Jencks
> Fix For: scr-1.8.0
>
> Attachments: stacktrace2.log, stacktrace.log
>
>
> Pierre de Rop saw this running the integration tests:
> test_concurrent_injection_with_bundleContext(org.apache.felix.scr.integration.Felix3680_2Test)
> Time elapsed: 36.597 sec <<< ERROR!
> java.lang.NullPointerException
> at
> org.apache.felix.scr.impl.manager.DependencyManager.invokeUnbindMethod(DependencyManager.java:1710)
> at
> org.apache.felix.scr.impl.manager.SingleComponentManager.invokeUnbindMethod(SingleComponentManager.java:387)
> at
> org.apache.felix.scr.impl.manager.DependencyManager$MultipleDynamicCustomizer.removedService(DependencyManager.java:355)
> at
> org.apache.felix.scr.impl.manager.DependencyManager$MultipleDynamicCustomizer.removedService(DependencyManager.java:290)
> at
> org.apache.felix.scr.impl.manager.ServiceTracker$Tracked.customizerRemoved(ServiceTracker.java:1503)
> at
> org.apache.felix.scr.impl.manager.ServiceTracker$Tracked.customizerRemoved(ServiceTracker.java:1398)
> at
> org.apache.felix.scr.impl.manager.ServiceTracker$AbstractTracked.untrack(ServiceTracker.java:1258)
> at
> org.apache.felix.scr.impl.manager.ServiceTracker$Tracked.serviceChanged(ServiceTracker.java:1437)
> at
> org.apache.felix.framework.util.EventDispatcher.invokeServiceListenerCallback(EventDispatcher.java:932)
> at
> org.apache.felix.framework.util.EventDispatcher.fireEventImmediately(EventDispatcher.java:793)
> at
> org.apache.felix.framework.util.EventDispatcher.fireServiceEvent(EventDispatcher.java:543)
> at org.apache.felix.framework.Felix.fireServiceEvent(Felix.java:4260)
> at org.apache.felix.framework.Felix.access$000(Felix.java:74)
> at org.apache.felix.framework.Felix$1.serviceChanged(Felix.java:390)
> at
> org.apache.felix.framework.ServiceRegistry.unregisterService(ServiceRegistry.java:148)
> at
> org.apache.felix.framework.ServiceRegistrationImpl.unregister(ServiceRegistrationImpl.java:127)
> at
> org.apache.felix.scr.integration.components.felix3680_2.Main$RegistrationHelper$2.run(Main.java:136)
> at
> java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
> at
> java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
> at java.lang.Thread.run(Thread.java:722)
> The problem is that a service is being removed between the time the component
> instance is being created and the time the dependency manager is opened, and
> there is no open latch yet. I see that the EdgeInfos are never reused, so
> the fix appears to be to:
> 1. set up all the edgeInfos in the ComponentContextImpl constructor, avoiding
> a race (not observed AFAIK) in getEdgeInfo
> 2. make the open latch and close latch in EdgeInfo final
> 3. in DependencyManager.invokeUnbind and invokeUpdated make sure open is
> complete before checking outOfRange.
> 4. distinguish between out of range before and after.
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