Threads stuck, gradually, slowly...Have you any suggestions?

Hi!

 

Java 5 threading here.

 

I have an Executer with 10 threads,

 

threads are busy in e-mail sending tasks execution.

 

Gradually (1 thread in 5 hours) threads stuck in TIMED_WAITING state, from which they never revoked,

 

example of thread state is here, taken by jconsole:

 

Name: pool-4-thread-1
State: TIMED_WAITING on java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject@3125fe1
Total blocked: 0  Total waited: 7,609

Stack trace: 
 sun.misc.Unsafe.park(Native Method)
java.util.concurrent.locks.LockSupport.parkNanos(LockSupport.java:198)
java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject.awaitNanos(AbstractQueuedSynchronizer.java:2025)
java.util.concurrent.ArrayBlockingQueue.poll(ArrayBlockingQueue.java:342)
com.idi.mailer.executor.impl.ResultsQueue.pull(ResultsQueue.java:66)
com.idi.mailer.executor.impl.SerialMailExecutor$FinalizerTask.run(SerialMailExecutor.java:466)
java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886)
java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908)
java.lang.Thread.run(Thread.java:662)

 

Gradually all 10 threads get into that state.

 

They are not using common resources. They are not waiting each other. No locks possible.

 

What I do now to fix the matter, I recognize the failure at the end and restart the entire executer.

 

It looks like a VM bug, because I looked into similar posts and all they end up in some VM problem...

 

Have you any idea?

 

Thanks.

 

Peter.

 

 

 

Developer