test/jdk/java/util/concurrent/LinkedTransferQueue/WhiteBox.java

8246677: LinkedTransferQueue and SynchronousQueue synchronization updates
Reviewed-by: martin

*** 59,82 ****
  
  @Test
  public class WhiteBox {
      final ThreadLocalRandom rnd = ThreadLocalRandom.current();
      final VarHandle HEAD, TAIL, ITEM, NEXT;
-     final int SWEEP_THRESHOLD;
  
      public WhiteBox() throws ReflectiveOperationException {
          Class<?> qClass = LinkedTransferQueue.class;
          Class<?> nodeClass = Class.forName(qClass.getName() + "$Node");
          MethodHandles.Lookup lookup
              = MethodHandles.privateLookupIn(qClass, MethodHandles.lookup());
          HEAD = lookup.findVarHandle(qClass, "head", nodeClass);
          TAIL = lookup.findVarHandle(qClass, "tail", nodeClass);
          NEXT = lookup.findVarHandle(nodeClass, "next", nodeClass);
          ITEM = lookup.findVarHandle(nodeClass, "item", Object.class);
-         SWEEP_THRESHOLD = (int)
-             lookup.findStaticVarHandle(qClass, "SWEEP_THRESHOLD", int.class)
-             .get();
      }
  
      Object head(LinkedTransferQueue q) { return HEAD.getVolatile(q); }
      Object tail(LinkedTransferQueue q) { return TAIL.getVolatile(q); }
      Object item(Object node)           { return ITEM.getVolatile(node); }
--- 59,78 ----
*** 365,404 ****
      public void testSerialization() {
          LinkedTransferQueue q = serialClone(new LinkedTransferQueue());
          assertInvariants(q);
      }
  
-     public void cancelledNodeSweeping() throws Throwable {
-         assertEquals(SWEEP_THRESHOLD & (SWEEP_THRESHOLD - 1), 0);
-         LinkedTransferQueue q = new LinkedTransferQueue();
-         Thread blockHead = null;
-         if (rnd.nextBoolean()) {
-             blockHead = new Thread(
-                 () -> { try { q.take(); } catch (InterruptedException ok) {}});
-             blockHead.start();
-             while (nodeCount(q) != 2) { Thread.yield(); }
-             assertTrue(q.hasWaitingConsumer());
-             assertEquals(q.getWaitingConsumerCount(), 1);
-         }
-         int initialNodeCount = nodeCount(q);
- 
-         // Some dead nodes do in fact accumulate ...
-         if (blockHead != null)
-             while (nodeCount(q) < initialNodeCount + SWEEP_THRESHOLD / 2)
-                 q.poll(1L, TimeUnit.MICROSECONDS);
- 
-         // ... but no more than SWEEP_THRESHOLD nodes accumulate
-         for (int i = rnd.nextInt(SWEEP_THRESHOLD * 10); i-->0; )
-             q.poll(1L, TimeUnit.MICROSECONDS);
-         assertTrue(nodeCount(q) <= initialNodeCount + SWEEP_THRESHOLD);
- 
-         if (blockHead != null) {
-             blockHead.interrupt();
-             blockHead.join();
-         }
-     }
- 
      /** Checks conditions which should always be true. */
      void assertInvariants(LinkedTransferQueue q) {
          assertNotNull(head(q));
          assertNotNull(tail(q));
          // head is never self-linked (but tail may!)
--- 361,370 ----