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https://issues.apache.org/jira/browse/FELIX-6253?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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Carsten Ziegeler updated FELIX-6253:
------------------------------------
Description:
There is a possible deadlock in the HttpServiceRuntimeImpl updateChangeCount
similar to FELIX-6252
T
was:
There is a possible deadlock in the ComponentRegistry and it goes like this:
The update of the change count is setting up a timer to execute a task while it
is holding a lock. The task in turn, is grabbing that lock when activated and
calls into the service registry while holding the lock.
Now, when a service gets unregistered that is coming from a factory - the
service registry will do an upcall that triggers scr to update the change count
and hence, trying to grab the lock mentioned above.
That can cause a case where the task has the lock and is waiting in the service
registry which is waiting on scr, which is waiting for the lock.
E.g.:
For the tasks:
{code:java}
java.lang.Thread.State: WAITING (parking)
at sun.misc.Unsafe.park(Native Method)
- parking to wait for <0x00000007bc02ea40> (a
java.util.concurrent.CountDownLatch$Sync)
at java.util.concurrent.locks.LockSupport.park(LockSupport.java:175)
at
java.util.concurrent.locks.AbstractQueuedSynchronizer.parkAndCheckInterrupt(AbstractQueuedSynchronizer.java:836)
at
java.util.concurrent.locks.AbstractQueuedSynchronizer.doAcquireSharedInterruptibly(AbstractQueuedSynchronizer.java:997)
at
java.util.concurrent.locks.AbstractQueuedSynchronizer.acquireSharedInterruptibly(AbstractQueuedSynchronizer.java:1304)
at java.util.concurrent.CountDownLatch.await(CountDownLatch.java:231)
at
org.apache.felix.framework.ServiceRegistry.getService(ServiceRegistry.java:368)
at
org.apache.felix.framework.EventDispatcher.filterListenersUsingHooks(EventDispatcher.java:618)
at
org.apache.felix.framework.EventDispatcher.fireServiceEvent(EventDispatcher.java:542)
at org.apache.felix.framework.Felix.fireServiceEvent(Felix.java:4833)
at org.apache.felix.framework.Felix.access$000(Felix.java:112)
at org.apache.felix.framework.Felix$1.serviceChanged(Felix.java:434)
at
org.apache.felix.framework.ServiceRegistry.servicePropertiesModified(ServiceRegistry.java:612)
at
org.apache.felix.framework.ServiceRegistrationImpl.setProperties(ServiceRegistrationImpl.java:132)
at
org.apache.felix.scr.impl.ComponentRegistry$4.run(ComponentRegistry.java:743)
- locked <0x000000074376fb00> (a java.lang.Object)
at java.util.TimerThread.mainLoop(Timer.java:555)
at java.util.TimerThread.run(Timer.java:505)
{code}
and for the update:
{code:java}
java.lang.Thread.State: BLOCKED (on object monitor) at
org.apache.felix.scr.impl.ComponentRegistry.updateChangeCount(ComponentRegistry.java:722)
- waiting to lock <0x000000074376fb00> (a java.lang.Object) at
org.apache.felix.scr.impl.BundleComponentActivator.updateChangeCount(BundleComponentActivator.java:778)
at
org.apache.felix.scr.impl.manager.AbstractComponentManager.setState(AbstractComponentManager.java:1420)
at
org.apache.felix.scr.impl.manager.SingleComponentManager.getServiceInternal(SingleComponentManager.java:962)
at
org.apache.felix.scr.impl.manager.SingleComponentManager.getService(SingleComponentManager.java:900)
at
org.apache.felix.framework.ServiceRegistrationImpl.getFactoryUnchecked(ServiceRegistrationImpl.java:348)
at
org.apache.felix.framework.ServiceRegistrationImpl.getService(ServiceRegistrationImpl.java:248)
at
org.apache.felix.framework.ServiceRegistry.getService(ServiceRegistry.java:350)
at
org.apache.felix.framework.EventDispatcher.filterListenersUsingHooks(EventDispatcher.java:618)
at
org.apache.felix.framework.EventDispatcher.fireServiceEvent(EventDispatcher.java:542)
at org.apache.felix.framework.Felix.fireServiceEvent(Felix.java:4833) at
org.apache.felix.framework.Felix.access$000(Felix.java:112) at
org.apache.felix.framework.Felix$1.serviceChanged(Felix.java:434) at
org.apache.felix.framework.ServiceRegistry.unregisterService(ServiceRegistry.java:170)
{code}
[~cziegeler], could you have a look and see if that is fixable by not holding
the lock while calling into the serviceregistry?
> Potential deadlock in HttpServiceRuntimeImpl updateChangeCount
> --------------------------------------------------------------
>
> Key: FELIX-6253
> URL: https://issues.apache.org/jira/browse/FELIX-6253
> Project: Felix
> Issue Type: Bug
> Components: HTTP Service
> Affects Versions: http.base-4.0.8, http.bridge-4.0.10, http.jetty-4.0.16
> Reporter: Karl Pauls
> Assignee: Carsten Ziegeler
> Priority: Major
> Fix For: http.base-4.0.10, http.jetty-4.0.20, http.bridge-4.0.12
>
>
> There is a possible deadlock in the HttpServiceRuntimeImpl updateChangeCount
> similar to FELIX-6252
> T
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