You are viewing a plain text version of this content. The canonical link for it is here.
Posted to dev@felix.apache.org by "Xander Uiterlinden (JIRA)" <ji...@apache.org> on 2013/09/23 09:39:02 UTC
[jira] [Commented] (FELIX-3910) Race conditions in
DependencyManager
[ https://issues.apache.org/jira/browse/FELIX-3910?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13774356#comment-13774356 ]
Xander Uiterlinden commented on FELIX-3910:
-------------------------------------------
Ik just reviewed the patch. I see it introduces a SerialExecutor to prevent race conditions. With revision r1488970 I introduced a guarded block to guarantee execution of callback methods in the correct order. See the enqueueCallback, waitForCallbackLock, execute and releaseCallback methods. Maybe we can remove the serial executor introduced in the patch and use this mechanism for the non-aspect aware callbacks as well ?
> 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, FELIX-3910.patch.2, FELIX-3910.patch.3
>
>
> 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)
--
This message is automatically generated by JIRA.
If you think it was sent incorrectly, please contact your JIRA administrators
For more information on JIRA, see: http://www.atlassian.com/software/jira