[SLING-4224] Avoid NPE after HeartbeatHandler deactivation

• Type: Bug
• Status: Closed
• Priority: Minor
• Resolution: Fixed
• Affects Version/s: Discovery Impl 1.0.12
• Fix Version/s: Discovery Impl 1.1.0
• Component/s: Extensions
• Assignee: Stefan Egli
• Reporter: Stefan Egli
• Created: 07/Dec/14 16:21
• Updated: 31/Mar/15 13:41
• Resolved: 26/Jan/15 09:28

Description

The following order of messages, including a NPE, where witnessed:

27.11.2014 17:04:53.913 *INFO* [FelixShutdown] org.apache.felix.framework BundleEvent STOPPING
...
27.11.2014 17:05:07.080 *INFO* [FelixStartLevel] org.apache.sling.discovery.impl Service [org.apache.sling.discovery.impl.common.heartbeat.HeartbeatHandler,3149] ServiceEvent UNREGISTERING
...
27.11.2014 17:05:07.094 *ERROR* [pool-9-thread-1] org.apache.sling.commons.scheduler.impl.QuartzScheduler Exception during job execution of org.apache.sling.discovery.impl.common.heartbeat.HeartbeatHandler@4d2581b9 : null
java.lang.NullPointerException: null
               at org.apache.sling.discovery.impl.cluster.voting.VotingHelper.listOpenNonWinningVotings(VotingHelper.java:53)
               at org.apache.sling.discovery.impl.common.heartbeat.HeartbeatHandler.doCheckView(HeartbeatHandler.java:441)
               at org.apache.sling.discovery.impl.common.heartbeat.HeartbeatHandler.checkView(HeartbeatHandler.java:409)
               at org.apache.sling.discovery.impl.common.heartbeat.HeartbeatHandler.run(HeartbeatHandler.java:212)
               at org.apache.sling.commons.scheduler.impl.QuartzJobExecutor.execute(QuartzJobExecutor.java:105)
               at org.quartz.core.JobRunShell.run(JobRunShell.java:207)
               at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
               at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
               at java.lang.Thread.run(Thread.java:745)

This indicates, that the HeartbeatHandler is executing the checkView method even after deactivation - thus having the config null - thus running into a NPE.