NullPointerException occurs when using QueuelessExcecutor

Issue

The following NullPointerException appears every keepalive-time seconds when using QueuelessExecutor.

ERROR [org.jboss.threads.executor] (test-thread2-threads - 1) Task execution failed for task org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor@1675e00: java.lang.NullPointerException
    at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:521) [jbossweb-7.0.17.Final-redhat-1.jar:]
    at org.jboss.threads.SimpleDirectExecutor.execute(SimpleDirectExecutor.java:33) [jboss-threads-2.0.0.GA-redhat-2.jar:2.0.0.GA-redhat-2]
    at org.jboss.threads.QueuelessExecutor$Worker.run(QueuelessExecutor.java:614) [jboss-threads-2.0.0.GA-redhat-2.jar:2.0.0.GA-redhat-2]
    at java.lang.Thread.run(Thread.java:636) [rt.jar:1.6.0_20]
    at org.jboss.threads.JBossThread.run(JBossThread.java:122) [jboss-threads-2.0.0.GA-redhat-2.jar:2.0.0.GA-redhat-2]