[jira] [Updated] (FELIX-3910) Race conditions in DependencyManager

["Pierre De Rop (JIRA)" <ji...@apache.org>]

     [ https://issues.apache.org/jira/browse/FELIX-3910?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]

Pierre De Rop updated FELIX-3910:
---------------------------------

    Attachment: FELIX-3910-patch

Attached a proposed patch, which seems to resolve the issue.
Notice that the other dependencies (ConfigurationDependency, etc ...) might have to be patched in a similar way.

Mainly, the patch is located in the ServiceDependencyImpl.java and is simply reusing the SerialExecutor of the components the ServiceDependency is attached to. 

I would appreciate if some DM committers could take a look at this patch; may be I have missed something and there is another way to go ?

thanks. 
/pierre
                
> Race conditions in DependencyManager
> ------------------------------------
>
>                 Key: FELIX-3910
>                 URL: https://issues.apache.org/jira/browse/FELIX-3910
>             Project: Felix
>          Issue Type: Bug
>          Components: Dependency Manager
>    Affects Versions: dependencymanager-3.0.0
>         Environment: jdk1.6, jdk1.7, linux fc16
>            Reporter: Pierre De Rop
>         Attachments: FELIX-3910-patch
>
>
> In a multi threaded context, where dependencies are injected concurrently from different threads, we  came across some exceptions which seem to take place from dependencymanager.
> I have tried to reproduce the problems using a paxexam test which I will commit.
> Not all exceptions are reproduced by the test case, but I think that the testcase really reproduces a problem. 
> I also have a candidate patch, which I will submit to this jira issue.
> Here are the exceptions we have seen:
> first stacktrace seen:
> ===============
> ERROR: Bundle test.dm [21] EventDispatcher: Error during dispatch. (java.lang.NullPointerException)
> java.lang.NullPointerException
>         at org.apache.felix.dm.impl.dependencies.ServiceDependencyImpl.addedService(ServiceDependencyImpl.java:481)
>         at org.apache.felix.dm.tracker.ServiceTracker$Tracked.customizerAdded(ServiceTracker.java:1325)
>         at org.apache.felix.dm.tracker.AbstractTracked.trackAdding(AbstractTracked.java:290)
>         at org.apache.felix.dm.tracker.AbstractTracked.track(AbstractTracked.java:236)
>         at org.apache.felix.dm.tracker.ServiceTracker$Tracked.serviceChangedHideAspects(ServiceTracker.java:1206)
>         at org.apache.felix.dm.tracker.ServiceTracker$Tracked.serviceChanged(ServiceTracker.java:1101)
>         at org.apache.felix.framework.util.EventDispatcher.invokeServiceListenerCallback(EventDispatcher.java:932)
>         at org.apache.felix.framework.util.EventDispatcher.fireEventImmediately(EventDispatcher.java:793)
>         at org.apache.felix.framework.util.EventDispatcher.fireServiceEvent(EventDispatcher.java:543)
>         at org.apache.felix.framework.Felix.fireServiceEvent(Felix.java:4260)
>         at org.apache.felix.framework.Felix.registerService(Felix.java:3275)
>         at org.apache.felix.framework.BundleContextImpl.registerService(BundleContextImpl.java:346)
>         at org.apache.felix.framework.BundleContextImpl.registerService(BundleContextImpl.java:320)
>         at test.dm.race.RaceTest$RegistrationHelper$1.run(RaceTest.java:104)
>         at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886)
>         at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908)
>         at java.lang.Thread.run(Thread.java:662)
> second exceptions:
> ==============
> ERROR: EventDispatcher: Error during dispatch. (java.lang.NullPointerException)
> java.lang.NullPointerException
>         at org.apache.felix.dm.impl.ComponentImpl.invokeCallbackMethod(ComponentImpl.java:686)
>         at org.apache.felix.dm.impl.dependencies.ServiceDependencyImpl.invoke(ServiceDependencyImpl.java:704)
>         at org.apache.felix.dm.impl.dependencies.ServiceDependencyImpl.invokeRemoved(ServiceDependencyImpl.java:666)
>         at org.apache.felix.dm.impl.dependencies.ServiceDependencyImpl.removedService(ServiceDependencyImpl.java:520)
>         at org.apache.felix.dm.tracker.ServiceTracker$Tracked.customizerRemoved(ServiceTracker.java:1351)
>         at org.apache.felix.dm.tracker.AbstractTracked.untrack(AbstractTracked.java:359)
>         at org.apache.felix.dm.tracker.ServiceTracker$Tracked.serviceChangedHideAspects(ServiceTracker.java:1285)
>         at org.apache.felix.dm.tracker.ServiceTracker$Tracked.serviceChanged(ServiceTracker.java:1101)
>         at org.apache.felix.framework.util.EventDispatcher.invokeServiceListenerCallback(EventDispatcher.java:878)
>         at org.apache.felix.framework.util.EventDispatcher.fireEventImmediately(EventDispatcher.java:732)
>         at org.apache.felix.framework.util.EventDispatcher.fireServiceEvent(EventDispatcher.java:662)
>         at org.apache.felix.framework.Felix.fireServiceEvent(Felix.java:3587)
>         at org.apache.felix.framework.Felix.access$000(Felix.java:40)
>         at org.apache.felix.framework.Felix$1.serviceChanged(Felix.java:625)
>         at org.apache.felix.framework.ServiceRegistry.unregisterService(ServiceRegistry.java:117)
>         at org.apache.felix.framework.ServiceRegistrationImpl.unregister(ServiceRegistrationImpl.java:128)
>         at org.apache.felix.dm.test.RaceTest$AFactory$2.run(RaceTest.java:151)
>         at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886)
>         at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908)
>         at java.lang.Thread.run(Thread.java:662)

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