locked org.apache.skywalking.apm.dependencies.io.netty.channel.nio.SelectedSelectionKeySet

[renhaizhou]

There are many blocking logs during pressure measurement. What is the reason？

"grpc-nio-worker-ELG-1-4" Id=28 RUNNABLE (in native)
at sun.nio.ch.EPollArrayWrapper.epollWait(Native Method)
at sun.nio.ch.EPollArrayWrapper.poll(EPollArrayWrapper.java:269)
at sun.nio.ch.EPollSelectorImpl.doSelect(EPollSelectorImpl.java:79)
at sun.nio.ch.SelectorImpl.lockAndDoSelect(SelectorImpl.java:86)
- locked org.apache.skywalking.apm.dependencies.io.netty.channel.nio.SelectedSelectionKeySet@1ee09943
- locked java.util.Collections$UnmodifiableSet@2f6801ee
- locked sun.nio.ch.EPollSelectorImpl@28e46bcd
at sun.nio.ch.SelectorImpl.select(SelectorImpl.java:97)
at org.apache.skywalking.apm.dependencies.io.netty.channel.nio.SelectedSelectionKeySetSelector.select(SelectedSelectionKeySetSelector.java:62)
at org.apache.skywalking.apm.dependencies.io.netty.channel.nio.NioEventLoop.select(NioEventLoop.java:807)
at org.apache.skywalking.apm.dependencies.io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:457)
at org.apache.skywalking.apm.dependencies.io.netty.util.concurrent.SingleThreadEventExecutor$4.run(SingleThreadEventExecutor.java:989)
at org.apache.skywalking.apm.dependencies.io.netty.util.internal.ThreadExecutorMap$2.run(ThreadExecutorMap.java:74)
at org.apache.skywalking.apm.dependencies.io.netty.util.concurrent.FastThreadLocalRunnable.run(FastThreadLocalRunnable.java:30)
at java.lang.Thread.run(Thread.java:745)