High CPU in XNIO accept thread

Issue

• We see high CPU in EAP 7's XNIO accept threads:

"default Accept" #125 prio=5 os_prio=0 tid=0x00007fc6e81ee000 nid=0xbcea runnable [0x00007fc6ed7d8000]
   java.lang.Thread.State: RUNNABLE
    at java.lang.Throwable.fillInStackTrace(Native Method)
    at java.lang.Throwable.fillInStackTrace(Throwable.java:783)
    - locked <0x00000007170b0b00> (a java.io.IOException)
    at java.lang.Throwable.(Throwable.java:265)
    at java.lang.Exception.(Exception.java:66)
    at java.io.IOException.(IOException.java:58)
    at sun.nio.ch.ServerSocketChannelImpl.accept0(Native Method)
    at sun.nio.ch.ServerSocketChannelImpl.accept(ServerSocketChannelImpl.java:422)
    at sun.nio.ch.ServerSocketChannelImpl.accept(ServerSocketChannelImpl.java:250)
    - locked <0x00000005c222d048> (a java.lang.Object)
    at org.xnio.nio.QueuedNioTcpServer.handleReady(QueuedNioTcpServer.java:466)
    at org.xnio.nio.QueuedNioTcpServerHandle.handleReady(QueuedNioTcpServerHandle.java:38)
    at org.xnio.nio.WorkerThread.run(WorkerThread.java:567)