[FELIX-341] Intermittent exception during Felix shutdown

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: framework-1.0.0
• Fix Version/s: scr-1.0.0
• Component/s: Declarative Services (SCR)
• Assignee: Felix Meschberger
• Reporter: Rajini Sivaram
• Created: 21/Aug/07 08:32
• Updated: 30/May/08 18:15
• Resolved: 30/Aug/07 14:56

Description

One of my testcases intermittently throws an exception during shutdown. I have managed to recreate the exception under a debugger, and it shows two threads trying to unregister the same service. The test fails only when declarative services are used. I am using Felix 1.0.0 framework and the latest snapshot of SCR. The test uses multiple versions of a bundle, but I am not sure if that has anything to do with the exception.

The exception thrown is:

— Exception with component : Unexpected problem executing task —
java.lang.IllegalStateException: Service already unregistered.
at org.apache.felix.framework.ServiceRegistrationImpl.unregister (ServiceRegistrationImpl.java:105)
at org.apache.felix.scr.AbstractComponentManager.unregisterComponentService(AbstractComponentManager.java:503)
at org.apache.felix.scr.AbstractComponentManager.deactivateInternal (AbstractComponentManager.java:369)
at org.apache.felix.scr.AbstractComponentManager.access$200(AbstractComponentManager.java:55)
at org.apache.felix.scr.AbstractComponentManager$3.run(AbstractComponentManager.java :176)
at org.apache.felix.scr.ComponentActorThread.run(ComponentActorThread.java:81)

Here is the stack trace of the two threads under the debugger (both are using the same object):

Thread [FelixStartLevel] (Suspended (breakpoint at line 97 in ServiceRegistrationImpl))
ServiceRegistrationImpl.unregister() line: 97
ServiceRegistry.unregisterServices (Bundle) line: 119
Felix._stopBundle(FelixBundle, boolean) line: 1946
Felix.stopBundle(FelixBundle, boolean) line: 1866
Felix.setFrameworkStartLevel (int) line: 1080
StartLevelImpl.run() line: 258
Thread.run() line: 803
Thread [SCR Component Actor] (Suspended (breakpoint at line 97 in ServiceRegistrationImpl))
ServiceRegistrationImpl.unregister() line: 97
ImmediateComponentManager(AbstractComponentManager).unregisterComponentService() line: 503
ImmediateComponentManager(AbstractComponentManager).deactivateInternal() line: 369
AbstractComponentManager.access$200(AbstractComponentManager) line: 55
AbstractComponentManager$3.run() line: 176
ComponentActorThread.run() line: 81

The exception thrown is the IllegalStateException from
public void unregister()
{
if (m_svcObj != null)

{ m_registry.unregisterService(m_bundle, this); m_svcObj = null; m_factory = null; }

else

{ throw new IllegalStateException("Service already unregistered."); }

}