This happened once in 9 b121 same binaries run on Linux.
Please refer to following test output:

----------messages:(4/368)----------
command: junit -Djava.util.concurrent.ForkJoinPool.common.parallelism=0 -Djsr166.testImplementationDetails=true JSR166TestCase
reason: User specified action: run junit/othervm/timeout=1000 -Djava.util.concurrent.ForkJoinPool.common.parallelism=0 -Djsr166.testImplementationDetails=true JSR166TestCase
Mode: othervm [/othervm specified]
elapsed time (seconds): 29.147
----------configuration:(0/0)----------
----------System.out:(0/0)----------
----------System.err:(15/1011)----------
JavaTest Message: JUnit Failure: testTransfer2(LinkedTransferQueueTest): expected:<1> but was:<0>
java.lang.Exception: JUnit test failure
at com.sun.javatest.regtest.JUnitAction$JUnitRunner.main(JUnitAction.java:128)
at com.sun.javatest.regtest.JUnitAction$JUnitRunner.main(JUnitAction.java:87)
at jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(java.base@9-ea/Native Method)
at jdk.internal.reflect.NativeMethodAccessorImpl.invoke(java.base@9-ea/NativeMethodAccessorImpl.java:62)
at jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(java.base@9-ea/DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(java.base@9-ea/Method.java:531)
at com.sun.javatest.regtest.agent.MainWrapper$MainThread.run(MainWrapper.java:110)
at java.lang.Thread.run(java.base@9-ea/Thread.java:843)