[POOL-326] Threading issue, NullPointerException and IllegalStateException in GenericKeyedObjectPool

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 2.4.2
• Fix Version/s: 2.6.1
• Assignee: Unassigned
• Reporter: Chris Allison
• Created: 12/May/17 15:48
• Updated: 05/Oct/19 01:01
• Resolved: 05/Oct/19 01:01

Description

I'll included a test to help reproduce this issue. Take a look at the embedded comments as it's extremely difficult to reproduce. I've seen the provided test show the failure on more than one PC so I believe it will show the problem.

Example stack trace for error on return:
java.util.concurrent.ExecutionException: java.lang.NullPointerException
at java.util.concurrent.FutureTask.report(FutureTask.java:122)
at java.util.concurrent.FutureTask.get(FutureTask.java:192)
at threading_pool.ObjectPoolIssue.run(ObjectPoolIssue.java:63)
at threading_pool.ObjectPoolIssue.main(ObjectPoolIssue.java:23)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at com.intellij.rt.execution.application.AppMain.main(AppMain.java:147)
Caused by: java.lang.NullPointerException
at org.apache.commons.pool2.impl.GenericKeyedObjectPool.returnObject(GenericKeyedObjectPool.java:474)
at threading_pool.ObjectPoolIssue$Task.call(ObjectPoolIssue.java:112)
at java.util.concurrent.FutureTask.run(FutureTask.java:266)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
at java.lang.Thread.run(Thread.java:745)

Example stack trace for error on borrow:
java.util.concurrent.ExecutionException: java.lang.NullPointerException
at java.util.concurrent.FutureTask.report(FutureTask.java:122)
at java.util.concurrent.FutureTask.get(FutureTask.java:192)
at threading_pool.ObjectPoolIssue.run(ObjectPoolIssue.java:63)
at threading_pool.ObjectPoolIssue.main(ObjectPoolIssue.java:23)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at com.intellij.rt.execution.application.AppMain.main(AppMain.java:147)
Caused by: java.lang.NullPointerException
at org.apache.commons.pool2.impl.GenericKeyedObjectPool.deregister(GenericKeyedObjectPool.java:1146)
at org.apache.commons.pool2.impl.GenericKeyedObjectPool.borrowObject(GenericKeyedObjectPool.java:438)
at org.apache.commons.pool2.impl.GenericKeyedObjectPool.borrowObject(GenericKeyedObjectPool.java:279)
at threading_pool.ObjectPoolIssue$Task.call(ObjectPoolIssue.java:108)
at java.util.concurrent.FutureTask.run(FutureTask.java:266)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
at java.lang.Thread.run(Thread.java:745)

Issue Links

• is related to: POOL-374 org.apache.commons.pool2.impl.GenericKeyedObjectPool.returnObject(K, T) should throw IllegalStateException instead of NullPointerException when a key is not found in the pool map