It looks as if there might be a deadlock/race condition.

ACTION: main -- Error. Agent error: java.lang.Exception: Agent timed out with a timeout of 480 seconds; check console log for any additional details
REASON: User specified action: run main ThreadMXBeanStateTest
TIME: 480.493 seconds
messages:
command: main ThreadMXBeanStateTest
reason: User specified action: run main ThreadMXBeanStateTest
Mode: agentvm
Timeout signalled after 480 seconds
Timeout information:
Running jstack on process 23612
2016-05-06 13:38:40
Full thread dump Java HotSpot(TM) 64-Bit Server VM (9-internal+0-2016-05-06-122827.danielfuchs.8156153 mixed mode):

"Attach Listener" #192 daemon prio=9 os_prio=64 tid=0x000000000095b000 nid=0xcc waiting on condition [0x0000000000000000]
   java.lang.Thread.State: RUNNABLE

"StateChanger" #191 daemon prio=5 os_prio=64 tid=0x0000000000d20800 nid=0xcb runnable [0xffff80ff9fee6000]
   java.lang.Thread.State: RUNNABLE
at jdk.internal.loader.BuiltinClassLoader.loadClassOrNull(java.base@9-internal/BuiltinClassLoader.java:376)
- locked <0x00000000e02bcd08> (a java.lang.Object)
at jdk.internal.loader.BuiltinClassLoader.loadClass(java.base@9-internal/BuiltinClassLoader.java:364)
at jdk.internal.loader.ClassLoaders$AppClassLoader.loadClass(java.base@9-internal/ClassLoaders.java:184)
at java.lang.ClassLoader.loadClass(java.base@9-internal/ClassLoader.java:473)
- locked <0x00000000e097dc10> (a java.lang.Object)
at java.lang.ClassLoader.loadClass(java.base@9-internal/ClassLoader.java:419)
at ThreadStateController.run(ThreadStateController.java:122)

"SameVMThread" #190 prio=5 os_prio=64 tid=0x0000000000962800 nid=0xca waiting for monitor entry [0xffff80ffa07ee000]
   java.lang.Thread.State: BLOCKED (on object monitor)
at java.lang.ClassLoader.loadClass(java.base@9-internal/ClassLoader.java:466)
- waiting to lock <0x00000000e097dc10> (a java.lang.Object)
at java.lang.ClassLoader.loadClass(java.base@9-internal/ClassLoader.java:419)
at jdk.testlibrary.Utils.adjustTimeout(Utils.java:283)
at ThreadStateController.pause(ThreadStateController.java:77)
at ThreadMXBeanStateTest.main(ThreadMXBeanStateTest.java:78)
at jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(java.base@9-internal/Native Method)
at jdk.internal.reflect.NativeMethodAccessorImpl.invoke(java.base@9-internal/NativeMethodAccessorImpl.java:62)
at jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(java.base@9-internal/DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(java.base@9-internal/Method.java:531)
at com.sun.javatest.regtest.agent.MainActionHelper$SameVMRunnable.run(MainActionHelper.java:226)
at java.lang.Thread.run(java.base@9-internal/Thread.java:804)

"MyThread" #74 daemon prio=5 os_prio=64 tid=0x0000000000b23000 nid=0x57 in Object.wait() [0xffff80ffa0ff8000]
   java.lang.Thread.State: WAITING (on object monitor)
at java.lang.Object.wait(java.base@9-internal/Native Method)
- waiting on <0x00000000e02faf98> (a java.lang.Object)
at java.lang.Object.wait(java.base@9-internal/Object.java:516)
at ThreadMXBeanProxy$MyThread.run(ThreadMXBeanProxy.java:117)
- waiting to re-lock in wait() <0x00000000e02faf98> (a java.lang.Object)
- locked <0x00000000e02f7d18> (a java.lang.Object)

"pool-1-thread-1" #12 daemon prio=5 os_prio=64 tid=0x0000000000a78000 nid=0x1a waiting on condition [0xffff80ffb1cf7000]
   java.lang.Thread.State: TIMED_WAITING (parking)
at jdk.internal.misc.Unsafe.park(java.base@9-internal/Native Method)
- parking to wait for <0x00000000e00bf8c0> (a java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject)
at java.util.concurrent.locks.LockSupport.parkNanos(java.base@9-internal/LockSupport.java:230)
at java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject.awaitNanos(java.base@9-internal/AbstractQueuedSynchronizer.java:2106)
at java.util.concurrent.ScheduledThreadPoolExecutor$DelayedWorkQueue.take(java.base@9-internal/ScheduledThreadPoolExecutor.java:1131)
at java.util.concurrent.ScheduledThreadPoolExecutor$DelayedWorkQueue.take(java.base@9-internal/ScheduledThreadPoolExecutor.java:848)
at java.util.concurrent.ThreadPoolExecutor.getTask(java.base@9-internal/ThreadPoolExecutor.java:1083)
at java.util.concurrent.ThreadPoolExecutor.runWorker(java.base@9-internal/ThreadPoolExecutor.java:1143)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(java.base@9-internal/ThreadPoolExecutor.java:632)
at java.lang.Thread.run(java.base@9-internal/Thread.java:804)

"Service Thread" #11 daemon prio=9 os_prio=64 tid=0x0000000000afb000 nid=0x18 runnable [0x0000000000000000]
   java.lang.Thread.State: RUNNABLE

"Common-Cleaner" #10 daemon prio=8 os_prio=64 tid=0x0000000000769800 nid=0x17 in Object.wait() [0xffff80ffb1ffa000]
   java.lang.Thread.State: TIMED_WAITING (on object monitor)
at java.lang.Object.wait(java.base@9-internal/Native Method)
- waiting on <0x00000000e022ee08> (a java.lang.ref.ReferenceQueue$Lock)
at java.lang.ref.ReferenceQueue.remove(java.base@9-internal/ReferenceQueue.java:151)
- waiting to re-lock in wait() <0x00000000e022ee08> (a java.lang.ref.ReferenceQueue$Lock)
at jdk.internal.ref.CleanerImpl.run(java.base@9-internal/CleanerImpl.java:148)
at java.lang.Thread.run(java.base@9-internal/Thread.java:804)
at jdk.internal.misc.InnocuousThread.run(java.base@9-internal/InnocuousThread.java:122)

"Sweeper thread" #9 daemon prio=9 os_prio=64 tid=0x00000000006c4800 nid=0x16 runnable [0x0000000000000000]
   java.lang.Thread.State: RUNNABLE

"C1 CompilerThread2" #8 daemon prio=9 os_prio=64 tid=0x00000000006c3000 nid=0x15 waiting on condition [0x0000000000000000]
   java.lang.Thread.State: RUNNABLE
   No compile task

"C2 CompilerThread1" #7 daemon prio=9 os_prio=64 tid=0x00000000006c0800 nid=0x14 waiting on condition [0x0000000000000000]
   java.lang.Thread.State: RUNNABLE
   No compile task

"C2 CompilerThread0" #6 daemon prio=9 os_prio=64 tid=0x00000000006bf000 nid=0x13 waiting on condition [0x0000000000000000]
   java.lang.Thread.State: RUNNABLE
   No compile task

"Signal Dispatcher" #5 daemon prio=9 os_prio=64 tid=0x00000000006bd000 nid=0x12 runnable [0x0000000000000000]
   java.lang.Thread.State: RUNNABLE

"Reference Pending List Locker" #4 daemon prio=9 os_prio=64 tid=0x00000000006bb800 nid=0x11 waiting on condition [0x0000000000000000]
   java.lang.Thread.State: RUNNABLE

"Finalizer" #3 daemon prio=8 os_prio=64 tid=0x000000000069e800 nid=0x10 in Object.wait() [0xffff80ffb59fe000]
   java.lang.Thread.State: WAITING (on object monitor)
at java.lang.Object.wait(java.base@9-internal/Native Method)
- waiting on <0x00000000e01ac408> (a java.lang.ref.ReferenceQueue$Lock)
at java.lang.ref.ReferenceQueue.remove(java.base@9-internal/ReferenceQueue.java:151)
- waiting to re-lock in wait() <0x00000000e01ac408> (a java.lang.ref.ReferenceQueue$Lock)
at java.lang.ref.ReferenceQueue.remove(java.base@9-internal/ReferenceQueue.java:172)
at java.lang.ref.Finalizer$FinalizerThread.run(java.base@9-internal/Finalizer.java:216)

"Reference Handler" #2 daemon prio=10 os_prio=64 tid=0x000000000069b000 nid=0xf in Object.wait() [0xffff80ffa1dfe000]
   java.lang.Thread.State: WAITING (on object monitor)
at java.lang.Object.wait(java.base@9-internal/Native Method)
- waiting on <0x00000000e01a9250> (a java.lang.ref.Reference$Lock)
at java.lang.Object.wait(java.base@9-internal/Object.java:516)
at java.lang.ref.Reference.tryHandlePending(java.base@9-internal/Reference.java:193)
- waiting to re-lock in wait() <0x00000000e01a9250> (a java.lang.ref.Reference$Lock)
at java.lang.ref.Reference$ReferenceHandler.run(java.base@9-internal/Reference.java:155)

"main" #1 prio=5 os_prio=64 tid=0x0000000000431000 nid=0x2 in Object.wait() [0xffff80ffbf18e000]
   java.lang.Thread.State: WAITING (on object monitor)
at java.lang.Object.wait(java.base@9-internal/Native Method)
- waiting on <0x00000000e0926930> (a java.lang.Thread)
at java.lang.Thread.join(java.base@9-internal/Thread.java:1313)
- waiting to re-lock in wait() <0x00000000e0926930> (a java.lang.Thread)
at java.lang.Thread.join(java.base@9-internal/Thread.java:1387)
at com.sun.javatest.regtest.agent.MainActionHelper.runClass(MainActionHelper.java:130)
at com.sun.javatest.regtest.agent.AgentServer.doMain(AgentServer.java:233)
at com.sun.javatest.regtest.agent.AgentServer.run(AgentServer.java:182)
at com.sun.javatest.regtest.agent.AgentServer.main(AgentServer.java:59)

"VM Thread" os_prio=64 tid=0x000000000068e000 nid=0xe runnable

"GC Thread#0" os_prio=64 tid=0x0000000000446000 nid=0x3 runnable

"GC Thread#1" os_prio=64 tid=0x0000000000447000 nid=0x4 runnable

"GC Thread#2" os_prio=64 tid=0x0000000000448800 nid=0x5 runnable

"GC Thread#3" os_prio=64 tid=0x000000000044a000 nid=0x6 runnable

"G1 Main Marker" os_prio=64 tid=0x000000000046d000 nid=0xc runnable

"G1 Marker#0" os_prio=64 tid=0x000000000046e800 nid=0xd runnable

"G1 Refine#0" os_prio=64 tid=0x0000000000450800 nid=0xa runnable

"G1 Refine#1" os_prio=64 tid=0x000000000044f000 nid=0x9 runnable

"G1 Refine#2" os_prio=64 tid=0x000000000044d800 nid=0x8 runnable

"G1 Refine#3" os_prio=64 tid=0x000000000044c000 nid=0x7 runnable

"G1 Young RemSet Sampling" os_prio=64 tid=0x0000000000452000 nid=0xb runnable

"VM Periodic Task Thread" os_prio=64 tid=0x0000000000ad1800 nid=0x19 waiting on condition

JNI global references: 541

--- Timeout information end.
elapsed time (seconds): 480.493
configuration:
Boot Layer
  class path: /scratch/opt/jprt/jib-data/install/java/re/jtreg/4.2/promoted/all/b02/bundles/jtreg_bin-4.2.zip/jtreg/lib/javatest.jar
              /scratch/opt/jprt/jib-data/install/java/re/jtreg/4.2/promoted/all/b02/bundles/jtreg_bin-4.2.zip/jtreg/lib/jtreg.jar
  patch: java.base /scratch/opt/jprt/T/P1/122827.danielfuchs/s/jdk/testoutput/jdk_management/JTwork/patches/java.base

Test Layer
  class path: /scratch/opt/jprt/T/P1/122827.danielfuchs/s/jdk/testoutput/jdk_management/JTwork/classes/java/lang/management/ThreadMXBean
              /scratch/opt/jprt/T/P1/122827.danielfuchs/s/jdk/test/java/lang/management/ThreadMXBean
              /scratch/opt/jprt/T/P1/122827.danielfuchs/s/jdk/testoutput/jdk_management/JTwork/classes/lib/testlibrary
              /scratch/opt/jprt/T/P1/122827.danielfuchs/s/jdk/test/lib/testlibrary
              /scratch/opt/jprt/T/P1/122827.danielfuchs/s/jdk/testoutput/jdk_management/JTwork/classes/java/lang/Thread
              /scratch/opt/jprt/T/P1/122827.danielfuchs/s/jdk/test/java/lang/Thread