--- old/test/jdk/java/util/concurrent/tck/ThreadLocalRandomTest.java 2021-01-05 09:12:35.224496362 -0800 +++ new/test/jdk/java/util/concurrent/tck/ThreadLocalRandomTest.java 2021-01-05 09:12:34.716500343 -0800 @@ -384,27 +384,24 @@ new AtomicReference<>(); final AtomicLong rand = new AtomicLong(); - long firstRand = 0; - ThreadLocalRandom firstThreadLocalRandom = null; - Runnable getRandomState = new CheckedRunnable() { public void realRun() { ThreadLocalRandom current = ThreadLocalRandom.current(); assertSame(current, ThreadLocalRandom.current()); - // test bug: the following is not guaranteed and not true in JDK8 - // assertNotSame(current, threadLocalRandom.get()); rand.set(current.nextLong()); threadLocalRandom.set(current); }}; - Thread first = newStartedThread(getRandomState); - awaitTermination(first); - firstRand = rand.get(); - firstThreadLocalRandom = threadLocalRandom.get(); + awaitTermination(newStartedThread(getRandomState)); + long firstRand = rand.get(); + ThreadLocalRandom firstThreadLocalRandom = threadLocalRandom.get(); + assertNotNull(firstThreadLocalRandom); for (int i = 0; i < NCALLS; i++) { - Thread t = newStartedThread(getRandomState); - awaitTermination(t); + awaitTermination(newStartedThread(getRandomState)); + if (testImplementationDetails) + // ThreadLocalRandom has been a singleton since jdk8. + assertSame(firstThreadLocalRandom, threadLocalRandom.get()); if (firstRand != rand.get()) return; }