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https://issues.apache.org/jira/browse/FELIX-5416?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16056276#comment-16056276
]
Thomas Watson commented on FELIX-5416:
--------------------------------------
This is a real issue and SCR code is wrong. Here is the sequence of events
that happen.
1) The thread stopping the framework is interrupted (in this case it was gogo,
but anything could do that).
2) The framework proceeds to stop the bundles
3) The SCR bundle is stopped (current thread is still interrupted)
4) SCR activator cases enters
org.apache.felix.scr.impl.ComponentActorThread.terminate()
5) a TERMINATION_TASK is scheduled and the lock on 'tasks' is immediately
obtained
Here is where the failure happens. If the consuming task code in
ComponentActorThread.run() does not obtain the 'tasks' lock in order to consume
the TERMINATION_TASK before step 5 obtains the 'tasks' lock in order to wait
for tasks to be empty we will enter an endless loop of interruptions and this
all happens while holding the 'tasks' lock which then also causes deadlock and
prevention of the TERMINATION_TASK from ever being consumed.
The terminate() method should be updated to something like the following in
order to correctly ignore interrupted exceptions.
{code}
void terminate()
{
schedule( TERMINATION_TASK );
while (!tasks.isEmpty()) {
final boolean interrupted = Thread.interrupted();
try {
tasks.wait();
} catch (InterruptedException e) {
logger.log(LogService.LOG_ERROR,
"Interrupted exception waiting for queue to empty", e);
} finally {
if (interrupted) { // restore interrupt status
Thread.currentThread().interrupt();
}
}
}
}
{code}
> Endless loop throwing InterruptedException when shutting down framework
> -----------------------------------------------------------------------
>
> Key: FELIX-5416
> URL: https://issues.apache.org/jira/browse/FELIX-5416
> Project: Felix
> Issue Type: Bug
> Components: Declarative Services (SCR)
> Affects Versions: scr-2.0.6
> Environment: OS: linux and windows
> Java Version: 1.8.0_111
> OSGi Impl: Apache Felix (5.6.1)
> Reporter: Jorge Cercas
>
> When shutting down the framework via the framework's stop method or in a gogo
> terminal shell via stop 0 command, the Apache Felix Declarative Services goes
> into a never ending loop with the following log ENTRIES:
> 2016-11-16 17:44:22,030 | ERROR | FelixStartLevel | scr
> | 7 - org.apache.felix.scr - 2.0.6 | Interrupted exception waiting
> for queue to empty
> java.lang.InterruptedException
> at java.lang.Object.wait(Native Method)[:1.8.0_111]
> at java.lang.Object.wait(Object.java:502)[:1.8.0_111]
> at
> org.apache.felix.scr.impl.ComponentActorThread.terminate(ComponentActorThread.java:131)[7:org.apache.felix.scr:2.0.6]
> at
> org.apache.felix.scr.impl.Activator.doStop(Activator.java:216)[7:org.apache.felix.scr:2.0.6]
> at
> org.apache.felix.utils.extender.AbstractExtender.stop(AbstractExtender.java:128)[7:org.apache.felix.scr:2.0.6]
> at
> org.apache.felix.scr.impl.Activator.stop(Activator.java:181)[7:org.apache.felix.scr:2.0.6]
> at
> org.apache.felix.framework.util.SecureAction.stopActivator(SecureAction.java:719)[org.apache.felix.framework-5.6.1.jar:]
> at
> org.apache.felix.framework.Felix.stopBundle(Felix.java:2610)[org.apache.felix.framework-5.6.1.jar:]
> at
> org.apache.felix.framework.Felix.setActiveStartLevel(Felix.java:1389)[org.apache.felix.framework-5.6.1.jar:]
> at
> org.apache.felix.framework.FrameworkStartLevelImpl.run(FrameworkStartLevelImpl.java:308)[org.apache.felix.framework-5.6.1.jar:]
> at java.lang.Thread.run(Thread.java:745)[:1.8.0_111]
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