AdaptorBasic
result: Error. Agent error: java.lang.Exception: Agent 14 timed out with a timeout of 480 seconds; check console log for any additional details

It looks like both client and server are waiting to receive a datagram - a datagram has probably been discarded by the system

"AgentVMThread" #16 prio=5 os_prio=31 cpu=18.56ms elapsed=483.11s allocated=641K defined_classes=76 tid=0x0000000131876800 nid=25863 runnable [0x000000017060e000]
   java.lang.Thread.State: RUNNABLE
at sun.nio.ch.DatagramChannelImpl.receive0(java.base@18-ea/Native Method)
at sun.nio.ch.DatagramChannelImpl.receiveIntoNativeBuffer(java.base@18-ea/DatagramChannelImpl.java:750)
at sun.nio.ch.DatagramChannelImpl.receive(java.base@18-ea/DatagramChannelImpl.java:728)
at sun.nio.ch.DatagramChannelImpl.trustedBlockingReceive(java.base@18-ea/DatagramChannelImpl.java:666)
at sun.nio.ch.DatagramChannelImpl.blockingReceive(java.base@18-ea/DatagramChannelImpl.java:635)
at sun.nio.ch.DatagramSocketAdaptor.receive(java.base@18-ea/DatagramSocketAdaptor.java:240)
at AdaptorBasic.test(AdaptorBasic.java:71)
at AdaptorBasic.test(AdaptorBasic.java:133)
at AdaptorBasic.main(AdaptorBasic.java:148)
at java.lang.invoke.LambdaForm$DMH/0x0000000300001c00.invokeStatic(java.base@18-ea/LambdaForm$DMH)
at java.lang.invoke.LambdaForm$MH/0x00000003000cd800.invoke(java.base@18-ea/LambdaForm$MH)
at java.lang.invoke.Invokers$Holder.invokeExact_MT(java.base@18-ea/Invokers$Holder)
at jdk.internal.reflect.DirectMethodHandleAccessor.invokeImpl(java.base@18-ea/DirectMethodHandleAccessor.java:155)
at jdk.internal.reflect.DirectMethodHandleAccessor.invoke(java.base@18-ea/DirectMethodHandleAccessor.java:104)
at java.lang.reflect.Method.invoke(java.base@18-ea/Method.java:577)
at com.sun.javatest.regtest.agent.MainActionHelper$AgentVMRunnable.run(MainActionHelper.java:312)
at java.lang.Thread.run(java.base@18-ea/Thread.java:833)

   Locked ownable synchronizers:
- <0x0000000790207c50> (a java.util.concurrent.locks.ReentrantLock$NonfairSync)

"Thread-0" #17 daemon prio=5 os_prio=31 cpu=1.16ms elapsed=483.10s allocated=1544K defined_classes=1 tid=0x00000001320bc000 nid=26371 runnable [0x000000017081a000]
   java.lang.Thread.State: RUNNABLE
at sun.nio.ch.DatagramChannelImpl.receive0(java.base@18-ea/Native Method)
at sun.nio.ch.DatagramChannelImpl.receiveIntoNativeBuffer(java.base@18-ea/DatagramChannelImpl.java:750)
at sun.nio.ch.DatagramChannelImpl.receive(java.base@18-ea/DatagramChannelImpl.java:728)
at sun.nio.ch.DatagramChannelImpl.trustedBlockingReceive(java.base@18-ea/DatagramChannelImpl.java:666)
at sun.nio.ch.DatagramChannelImpl.blockingReceive(java.base@18-ea/DatagramChannelImpl.java:635)
at sun.nio.ch.DatagramSocketAdaptor.receive(java.base@18-ea/DatagramSocketAdaptor.java:240)
at java.net.DatagramSocket.receive(java.base@18-ea/DatagramSocket.java:701)
at TestServers$AbstractUdpServer.run(TestServers.java:633)
at java.lang.Thread.run(java.base@18-ea/Thread.java:833)