一直存在的DubboResponseTimeoutScanTimer

基於dubbo2.5.3

每次通過jstack pid出來的結果中都有:

"DubboResponseTimeoutScanTimer" daemon prio=10 tid=0x00007f5990002800 nid=0x7ba6 sleeping[0x00007f59fe5d1000]
   java.lang.Thread.State: TIMED_WAITING (sleeping)
	at java.lang.Thread.sleep(Native Method)
	at com.alibaba.dubbo.remoting.exchange.support.DefaultFuture$RemotingInvocationTimeoutScan
 
.run(DefaultFuture.java:300)
	at java.lang.Thread.run(Thread.java:745)

   Locked ownable synchronizers:
	- None

在DefaultFuture.java中:

static {
   Thread th = new Thread(new RemotingInvocationTimeoutScan(), "DubboResponseTimeoutScanTimer");
   th.setDaemon(true);
   th.start();
}

而RemotingInvocationTimeoutScan