test/jdk/java/util/concurrent/tck/ThreadLocalRandomTest.java

8234131: Miscellaneous changes imported from jsr166 CVS 2020-12
Reviewed-by: martin

*** 382,412 ****
          // be polluted by previous tests.
          final AtomicReference<ThreadLocalRandom> threadLocalRandom =
              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();
  
          for (int i = 0; i < NCALLS; i++) {
!             Thread t = newStartedThread(getRandomState);
!             awaitTermination(t);
              if (firstRand != rand.get())
                  return;
          }
          fail("all threads generate the same pseudo-random sequence");
      }
--- 382,409 ----
          // be polluted by previous tests.
          final AtomicReference<ThreadLocalRandom> threadLocalRandom =
              new AtomicReference<>();
          final AtomicLong rand = new AtomicLong();
  
          Runnable getRandomState = new CheckedRunnable() {
              public void realRun() {
                  ThreadLocalRandom current = ThreadLocalRandom.current();
                  assertSame(current, ThreadLocalRandom.current());
                  rand.set(current.nextLong());
                  threadLocalRandom.set(current);
              }};
  
!         awaitTermination(newStartedThread(getRandomState));
!         long firstRand = rand.get();
!         ThreadLocalRandom firstThreadLocalRandom = threadLocalRandom.get();
!         assertNotNull(firstThreadLocalRandom);
  
          for (int i = 0; i < NCALLS; i++) {
!             awaitTermination(newStartedThread(getRandomState));
!             if (testImplementationDetails)
!                 // ThreadLocalRandom has been a singleton since jdk8.
!                 assertSame(firstThreadLocalRandom, threadLocalRandom.get());
              if (firstRand != rand.get())
                  return;
          }
          fail("all threads generate the same pseudo-random sequence");
      }