Jetty超时过期,checkIdleTimeout方法抛出的

各位:求助~

我在用jetty+cometd做comet服务,continuation机制已经加入,但是日志中出现了这样的异常

 java.util.concurrent.TimeoutException: Idle timeout expired: 40002/40000 ms
        at org.eclipse.jetty.io.IdleTimeout.checkIdleTimeout(IdleTimeout.java:153)
        at org.eclipse.jetty.io.IdleTimeout$1.run(IdleTimeout.java:50)
        at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:471)
        at java.util.concurrent.FutureTask.run(FutureTask.java:262)
        at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$201(ScheduledThreadPoolExecutor.java:178)
        at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:292)
        at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
        at java.lang.Thread.run(Thread.java:744)
201

堆栈完整,我已无解,求各位帮忙。jetty版本:jetty-9.1.0.v20131115