if (p == guard) {
          if (pred == null) {
            activeGuards = p.next;
          } else {
            pred.next = p.next;
          }
          p.next = null; // help GC
          break;
        }
      }
    }
  }

  /*
   * Methods that loop waiting on a guard's condition until the guard is satisfied, while recording

    suite.addTest(
        ConcurrentMapTestSuiteBuilder.using(
                new TestStringCacheGenerator(createCacheBuilder().weakKeys()))
            .named("LocalCache with weakKeys") // keys are string literals and won't be GC'd
            .withFeatures(
                CollectionSize.ANY,
                MapFeature.GENERAL_PURPOSE,
                CollectionFeature.SUPPORTS_ITERATOR_REMOVE)
            .createTestSuite());

    suite.addTest(
        ConcurrentMapTestSuiteBuilder.using(
                new TestStringCacheGenerator(createCacheBuilder().weakKeys()))
            .named("LocalCache with weakKeys") // keys are string literals and won't be GC'd
            .withFeatures(
                CollectionSize.ANY,
                MapFeature.GENERAL_PURPOSE,
                CollectionFeature.SUPPORTS_ITERATOR_REMOVE)
            .createTestSuite());

  //         Test s = suite();
  //         for (int i = 0; i < iters; ++i) {
  //             junit.textui.TestRunner.run(s);
  //             System.gc();
  //             System.runFinalization();
  //         }
  //         System.exit(0);
  //     }

  //     public static TestSuite newTestSuite(Object... suiteOrClasses) {

   * ThreadLocal is usually implemented with a WeakReference, which can have negative performance
   * properties; for example, calling WeakReference.get() on Android will block during an
   * otherwise-concurrent GC cycle.
   */
  private static final class TaskNonReentrantExecutor extends AtomicReference<RunningState>
      implements Executor, Runnable {

    /**

      RunnableExecutorPair list;
      synchronized (this) {
        if (executed) {
          return;
        }
        executed = true;
        list = runnables;
        runnables = null; // allow GC to free listeners even if this stays around for a while.
      }
      while (list != null) {
        executeListener(list.runnable, list.executor);
        list = list.next;
      }
    }

   * world. Figure out what sort of space-time tradeoff we're actually going to get here with the
   * *Map variants. This class is particularly hard to benchmark, because the benefit is not only in
   * less allocation, but also having the GC do less work to scan the heap because of fewer
   * references, which is particularly hard to quantify.
   */

  /** Creates an empty {@code CompactHashMap} instance. */

    executor.shutdown();
    assertThat(executor.awaitTermination(10, TimeUnit.SECONDS)).isTrue();
    assertThat(getDone(future2)).isFalse();
  }

  @J2ktIncompatible
  @GwtIncompatible
  @J2ObjCIncompatible // gc
  @AndroidIncompatible
  public void testCancellationWithReferencedObject() throws Exception {
    Object toBeGCed = new Object();
    WeakReference<Object> ref = new WeakReference<>(toBeGCed);

    executor.shutdown();
    assertThat(executor.awaitTermination(10, TimeUnit.SECONDS)).isTrue();
    assertThat(getDone(future2)).isFalse();
  }

  @J2ktIncompatible
  @GwtIncompatible
  @J2ObjCIncompatible // gc
  @AndroidIncompatible
  public void testCancellationWithReferencedObject() throws Exception {
    Object toBeGCed = new Object();
    WeakReference<Object> ref = new WeakReference<>(toBeGCed);

   * world. Figure out what sort of space-time tradeoff we're actually going to get here with the
   * *Map variants. This class is particularly hard to benchmark, because the benefit is not only in
   * less allocation, but also having the GC do less work to scan the heap because of fewer
   * references, which is particularly hard to quantify.
   */

  /** Creates an empty {@code CompactHashMap} instance. */