[POOL-337] EvictionTimer does not remove cancelled tasks from the executor, leading to an IllegalStateException when the evictor attempts to evict

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 2.5.0
• Assignee: Unassigned
• Reporter: Reinald Verheij
• Created: 30/Jan/18 11:49
• Updated: 26/May/18 05:50
• Resolved: 21/May/18 12:14

Description

EvictionTimer does not remove cancelled tasks from the executor, leading to an IllegalStateException when the evictor attempts to evict.

 

EvictionTimer::schedule() adds eviction tasks to the executor, but the cancel does not remove it. This is asymmetric and leads to the following exception:

java.lang.IllegalStateException: Pool not open
	at org.apache.commons.pool2.impl.BaseGenericObjectPool.assertOpen(BaseGenericObjectPool.java:713)
	at org.apache.commons.pool2.impl.GenericObjectPool.evict(GenericObjectPool.java:721)
	at org.apache.commons.pool2.impl.BaseGenericObjectPool$Evictor.run(BaseGenericObjectPool.java:1077)
	at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
	at java.util.concurrent.FutureTask.runAndReset(FutureTask.java:308)
	at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$301(ScheduledThreadPoolExecutor.java:180)
	at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:294)
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
	at java.lang.Thread.run(Thread.java:748)

I think the cancel would need to remember the future which returned from executor::scheduleWithFixedDelay() in schedule() and then do something like this (see EvictionTimer.java compared to original EvictionTimer.java.original-from-2.5.0.java )

if (futures.containsKey(task)) {
    futures.remove(task).cancel(false);
    executor.purge();
}

Issue Links

• blocks: DBCP-493 Upgrade Apache Commons Pool to the version 2.5.1
• links to: GitHub Pull Request #4