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https://issues.apache.org/jira/browse/CAMEL-26536?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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Work on CAMEL-26536 started by shashank.
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> camel-jms - with asyncStopListener=true, a JmsConsumer stopped and started
> again ends up started without a running listener container
> -------------------------------------------------------------------------------------------------------------------------------------
>
> Key: CAMEL-26536
> URL: https://issues.apache.org/jira/browse/CAMEL-26536
> Project: Camel
> Issue Type: Bug
> Components: camel-jms
> Reporter: shashank
> Assignee: shashank
> Priority: Major
>
> Found with a TLA+ model of {{JmsConsumer}} with {{asyncStartListener}} /
> {{asyncStopListener}} (the lifecycle thread, the asynchronous stop task and
> the asynchronous start task on the component's pool), cross-checked with a
> SPIN model, then reproduced on the real classes.
> With {{asyncStopListener=true}}, {{JmsConsumer.doStop}} submits
> {{stopAndDestroyListenerContainer()}} to the component's thread pool and
> returns, with {{listenerContainer}} still set. If the same consumer is
> started again before that task has run (route policies that stop and start
> the consumer, such as the leader-election policies {{HazelcastRoutePolicy}}
> and {{MasterRoutePolicy}} of camel-zookeeper-master, the JMX start/stop
> operations of the consumer, or code that calls {{stop()}} / {{start()}} on
> it), {{doStart}} sees the old listener container, does not create a new one,
> and initializes and starts it again. The stop task then reads the field,
> stops and destroys that container, and sets {{listenerContainer}} to null.
> The consumer reports Started but has no listener container and consumes
> nothing, with no error logged. If the stop task nulls the field while
> {{doStart}} is between its null check and {{afterPropertiesSet()}}, the start
> fails with a NullPointerException instead. The stop task also shuts down the
> private thread pool stored in {{executorService}}, which can be the pool of a
> listener container created by the new start.
> Short trace of the model:
> {noformat}
> 1 lifecycle : doStop -> listenerContainer = C1, submit stop task
> (JmsConsumer:216-219)
> 2 lifecycle : doStart -> listenerContainer != null, keep C1
> (:149)
> 3 lifecycle : C1.afterPropertiesSet(); C1.start(); initialized = true
> (:177-189)
> 4 stop task : listenerContainer.stop(); listenerContainer.destroy()
> (:195-196) -> C1 not running
> 5 stop task : listenerContainer = null; initialized = false
> (:203-205)
> -> consumer Started, no listener container
> {noformat}
> With {{asyncStartListener=true}} as well, the start task works on whatever
> the field holds when it runs: it can start the container the stop task
> destroys, hit the null field (NPE logged as "ignored"), or initialize a newer
> container a second time.
> The real-class test holds the tasks the consumer submits to the pool and runs
> them in a chosen order: stopping and starting the consumer with the stop task
> pending leaves {{getListenerContainer().isRunning()}} false and the next
> message is not consumed. Without hooks, 30 stop/start cycles of the consumer
> with the real pool (in-VM Artemis) ended 30 times without a running listener
> container (27 started without a listener, 3 starts failed with the NPE).
> A route restart ({{restartRoute}}, {{stopRoute}} + {{startRoute}}) is not
> affected, as the route creates a new consumer when it starts again.
> *Proposal:* {{doStop}} detaches the listener container under a lock of the
> consumer (the container, its private thread pool and the {{initialized}} flag
> are taken and cleared at once), and the stop task stops and destroys only the
> container (and pool) it was given, so a start that runs before the stop task
> creates a new listener container. {{doStart}} hands the container it created
> to the start task, which does nothing if the consumer no longer uses it, and
> after starting it checks again under the lock and stops and destroys it if
> the consumer was stopped meanwhile.
> Affected: main, 4.23.x, 4.22.x (the same {{JmsConsumer}} code), 4.18.x,
> 4.14.x (the same bug; {{initialized}} is set in {{doStart}} there).
> _Filed with Claude Code on behalf of allthingssecurity._
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