[FELIX-4385] NPE in Configuration Admin Service when deleting configuration

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: configadmin-1.8.2
• Fix Version/s: configadmin-1.8.2
• Component/s: Configuration Admin
• Assignee: Pierre De Rop
• Reporter: Pierre De Rop
• Created: 15/Jan/14 12:49
• Updated: 17/Mar/15 06:44
• Resolved: 03/Feb/14 15:26

Description

While writing a test for Apache Felix DependencyManager, I came across the following exception from ConfigAdmin 1.8.0 (under high load):

ERROR - CM Configuration Updater (Delete: pid=Aspect2.pid23) : Unexpected problem providing configuration Aspect2.pid23 to service [org.osgi.service.cm.ManagedService, id=117, bundle=26/local] - java.lang.NullPointerException
        at java.lang.StringBuffer.<init>(StringBuffer.java:120)
        at org.apache.felix.cm.impl.ConfigurationManager.getTargetedConfiguration(ConfigurationManager.java:523)
        at org.apache.felix.cm.impl.ConfigurationManager$ConfigurationProvider.provideReplacement(ConfigurationManager.java:1666)
        at org.apache.felix.cm.impl.ConfigurationManager$DeleteConfiguration.run(ConfigurationManager.java:1816)
        at org.apache.felix.cm.impl.UpdateThread.run(UpdateThread.java:103)
        at java.lang.Thread.run(Thread.java:722)

I suspect that this NPE occurs in the following scenario:

1- one ManagedService listening to a given configuration pid is being unregistered (from one thread)
2- concurrently, another thread is deleting the Configuration for the same PID the ManagedService was registered for.

I never wrote some test cases for configuration admin sub-project but I will try to write one in order to reproduce the issue.

For now, I'm using the attached patch, which seems to fix the problem.