REST threads hang in sun.nio.ch.PollArrayWrapper.poll0(Native Method) forever

in our production server I found a strange behavior where the REST POST threads sometimes hangs and remain in RUNNABLE state forever in method sun.nio.ch.PollArrayWrapper.poll0(Native Method)

after some days the wildfly app server become unresponsive and consume high CPU.

Attached a print screen form our javamelody monitoring that show some of the hanging threads in a RUNNABLE state for more that 50 hours (and counting).

and attached 3 thread dumps that show the threads still in runnable state